ALBERT

Notes: Users of photogrammetric data have often been puzzled by conflicting advice given by companies regarding achievable height accuracies which could be expected from varying scales of aerial photography. The author chairs the Photogrammetry Group which is convened under the auspices of the Council of the UK Land and Hydrographic Survey Association (TSA). The first aim of this Group was to establish some common ground among TSA member companies with regard to achievable heighting accuracies. A series of tests was carried out on the most commonly used photographic scales and guidelines were published to clients based on these tests. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Les utilisateurs des données photogrammétriques ont été souvent déconcertés par les avis contraires émanant des entreprises concernant les précisions altimétriques accessibles à partir de diverses échelles des photographies aériennes. Dans ce contexte, le Conseil de ľ‘Association britannique des levées terrestres et hydrographiques (TSA) a mis sur pied un Groupe “Photogrammétrie” et en a confié la présidence àľauteur. Le premier objectif de ce Groupe a consistéàétablir des bases communes aux entreprises membres de la TSA, en ce qui concerne les précisions altimétriques réalisables. On a effectué un ensemble ď essais sur les échelles des photographies aériennes les plus communément utilisées et ľ on a publicé, à partir de ces essais un opuscule destinéà guider les clients. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Die Nutzer photogrammetrischer Daten werden oft durch widerspriich-liche Ratschläge der Firmen in bezug auf die bei verschiedenen Bildmaβstäben erreichbare Höhengenauigkeit verwirrt. Der Autor leitet den photogrammetrischen Ausschuβ, der unter Aufsicht des Council des UK Land and Hydrographic Survey Association (TSA) einberufen wurde. Erstes Ziel dieses Gremiums war es, eine gemeinsame Grundlage unter den TSA-Mitgliedsgesellschaften im Hinblick auf erreichbare Höhengenauigkeit zu schaffen. Es wurde eine Reihe von Versuchen zu den am meisten verwendeten Bildmaβstäben durchgeführt, undes wurden daraufberuhende Richtlinien für Kunden veröffentlicht.

Notes: Cartography andphotogrammetry have always been strongly linked and this paper emphasises a view of cartography as a process of spatial data representation, rather than as a method of creating a product, a map. Of course, the definition of cartography must change with developments in its practice. An outline of the historical background to the subject is presented, followed by a consideration of the relationship between the cartographer and the user of the product. The basic problems involved in the transfer of information from the complex real world to a generalized cartographic product are analysed and technological aspects of the discipline are described. Contemporary applications of cartography include hazard mapping, links with GIS, tactile products and electronic hydrographic representation, all of which represent customer driven progress. It is concluded that the future of cartography is, overall, dependent on a graphical representation of high quality being supplied to the end user, rather than on the methods used to attain this objective. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé La cartographie et la photogramétrie ont toujours été liées étroitement ľune àľautre, et ľ‘on souligne dans cet article ľ‘idée que la cartographie est un systéme de représentation des données à trois dimensions, plutôt qu‘un ensemble de procédés de fabrication ďun produit, la carte. II est évident que la définition de la cartographie doit changer au fur et à mesure que des évolutions apparaissent dans sa pratique. Aprés un aperçu du contexte historique de ce thème, on examine les relations qui se développent entre le cartographe et ľutilisateur du produit. On analyse les problèmes fondamentaux du transfert ďinformations du monde réel, complexe, à un produit cartographique géneralisé et ľ‘on décrit la technologie qu'utilise cette discipline. Les applications récentes de la cartographie concernent la cartographie des risques naturels, les relations avec les SIG, les cartes qui se lisent par le toucher, et la représentation electronique de ľ‘hydrographic produits qui tous sont issus de cheminements pilotés en aval, par le client. On en déduit que la cartographie est, àľ'avenir, par dessus tout fonction ďune represséntation graphique de haute qualityé fournie à un utilisateur final, plutôt que de processus utilisé pour parvenir à cet objectif.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Kartographie und Photogrammetrie waren immer eng verbunden, und dieser Beitrag betont starker eine Auffassung von der Kartographie als einem Prozeβ der Darstellung von Raumdaten als ein Verfahren zur Herstellung eines Erzeugnisses, der Karte. Natürlich muβ sich die Definition der Kartographie bei Entwicklungen in ihrer Praxis ändern. Es erfolgt eine Skizzierung des historischen Hintergrundes des Gegenstands, gefolgt von Betrachtungen zur Beziehung zwischen Kartographen und dem Nutzer des Erzeugnisses. Die mit der Übertragung von Informationen aus der komplexen realen Welt in ein generalisiertes kartographisches System verbundenen grundlegenden Probleme werden analysiert, und es werden technologische Aspekte der Disziplin beschrieben. Zeitgenössische Anwendungen der Kartographie schlieβen die Kartierung von Katastrophen, Verbindungen zu GPS, gefühlsmäβge Erzeugnisse und elektronische hydrographische Darstellungen ein, die alle den vom Nutzer beeinflufiten Fortschritt darstellen. Es wird geschluffolgert, daft die Zukunft der Kartographie vor allem von der graphischen Darstellung hoher Qualität, die dem Endnutzer geliefert wird, abhängig ist undnicht so sehr von den Methoden, me dieses Ziel erreicht wird.

Notes: Since its foundation in 1982, the Institut Cartogràfic de Catalunya has been dealing with digital images. Though digital images and techniques were initially confined to remote sensing, they have been gradually transferred to and combined with photogrammetry. In addition to the development of remote sensing and digital orthophotography systems, this expertise has facilitated the introduction of commercially available digital photogrammetric systems (scanning and stereocompilation) which are now in full operation. The paper describes the experience in scanning, orthophotography production and stereocompilation, draws some conclusions and gives an insight of the future of digital photogrammetry. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé L‘Institut Cartographique de Catalogue s‘est intéressé au traitement des images numériques depuis le moment où il a été crée, en 1982. Bien qu'au début les images numériques et leur technologie aient été réservées à la télédétection, elles se sont trouvées peu à peu transférées et intégrées à la photogrammétrie. Ce savoir-faire a permis le développement des systèmes de télédétection et ď orthophotographie numérique et a, de plus, facilité la mise à disposition sur le marché de systèmes de photogrammétrie numérique qui sont maintenant pleinement opérationnels. On présente dans cet article ľ expérience acquise dans le domaine du balayage, de la production des orthophotographies et de la stéréocompilation, on en tire quelques conclusions et ľ on termine par un aperçu sur ľ‘avenir de la photogrammétrie numérique. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Seit seiner Gründung im Jahre 1982 hat sich das Institut Cartogràfic de Catalunya mit digitalen Bildern beschäftigt. Obwohl digitate Bilder und Verfahren ursprünglich auf die Fernerkundung begrenzt waren, wurden sie schrittweise auf die Photogrammetrie übertragen bzw. mit ihr kombiniert. Zusätzlich zur Entwicklung von Fernerkundung und digitaler Orthophoto-Systeme hat diese Erfahrung die Einführung kommerziell verfügbarer digitaler photogrammetrischer Systeme erleichtert, die jetzt überall in der Praxis angewendet werden. Der Beitrag beschreibt die Erfahrung bei der Abtastung, der Herstellung von Orthophotos und bei der Stereoauswertung und gibt einige Schluβfolgerungen und Aussichten in bezug auf die Digitalphotogrammetrie wieder.

Notes: The paper entitled The Photogrammetric Society Analogue Instrument Project was published in The Photogrammetric Record, 14(82): 565–582 (October 1993) and contained, as Appendix A, an extract from the Archive concerned with the history of the Zeiss Stereoplanigraph in Great Britain. In The Photogrammetric Record, 14(83): 769–782 (April 1994), three further Appendices were published which dealt with the Williamson Multiplex equipment and other instruments. In this third extract, the history of five other instruments of the Multiplex type are described. This brings to a close that section of the Archive dealing with instruments using direct optical projection.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On a publicé dans le numéro 14(82) (pp 565–582) ďoctobre 1993 du“Photogrammetric Record”ľarticle intitulé“le projet de la Société (britannique) de Photogrammétrie sur les instruments analogiques” et inséré dans ľannexe A un extrait des Archives relatif a ľhistorie du Stereoplan-igraphe Zeiss en Grande-Bretagne. On a publicé dans le numéro 14 (83) ďavril 1994 du“Photogrammetric Record”(pp 769–782) trois annexes supplémentaires qui traitaient de ľappareil Multiplex de Williamson et ďautres instruments. Dans ce troisième extrait, on présente ľhistorie de cinq autres appareils du type Multiplex. Cette partie des Archives qui traitait des appareils basés sur ľemploi ďuneprojection optique directe, se trouve ainsi achevee.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Der Beitrag mit dem Titel“The Photogrammetric Society Analogue Instrument Project”wurde im Photogrammetric Record, 14(82): 565–582 (Oktober 1993) veröffentlicht und enthielt als Anlage A einen Extrakt vom Archiv, das mit der Geschichte des Zeiss Steroplanigraph in Groβbritannien verbunden war. Im Photogrammetric Record, 14(83); 769–782 (April 1984) wurden 3 weitere Anlagen veröffentlicht, die vom Williamson Multiplex und anderen Geräten handelten. In diesem 3. Auszug wird die Geschichte von 5 anderen Geräten des Multiplex-Typs beschrieben. Das führt zum Abschluβ desjenigen Teils des Archivs, das sich mit Geräten mit direkter optischer Projektion befaβt.

Notes: An analysis is given of the modelling of XY stage errors in an analytical plotter by polynomial functions. This is discussed as an alternative to demanding strict mechanical accuracy in the stage construction. In an era of plentiful computational resources, it is concluded that apportioning more of the responsibility to the mathematical co-ordinate refinement is an effective strategy. A second degree polynomial is used for each of the two stages in an analytical plotter, modelling the systematic stage errors to within the variability of a single observation. A requirement for instrument stability is emphasized. Such techniques have application for other instruments such as image scanners. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On étudie la modélisation des erreurs des chariots XY ďun restituteur analytique en utilisant des fonctions polynomials. II s‘agit en fait de trouver une alternative à des exigences de prêcision mêcanique très strictes dans la réalisation de ces chariots. A une époque oùľon dispose ďune abondance de ressources en moyens de calcul, il apparait en effet relever ďune stratégie efficace de s'appuyer davantage sur les traitements mathématiques pour améliorer les valeurs des coordonnées. On utilise, pour chacun des deux chariots, un polynome du second degrè pour modéliser les erreurs systématiques des chariots, et les rendre inférieures aux erreurs propres à une observation unique. On insiste sur la nécessitéďune grande stabilityé instrumental. Ces processus peuvent également s'appliquer àďautres instruments comme les scanneurs ďimages. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Es wird die Modellierung von Fehlern des xy-Wagens bei analytischen Auswertegeräten mit Hilfe von Polynomen analysiert. Des wird als Alternative zur Forderung nach einer strengen mechanischen Genauigkeit bei der Bildwagenkonstruktion diskutiert. Im Zeitalter hervorragender Computer-Ressourcen, so wird geschluβfolgert, ist es eine effektive Strategie, sich mehr der mathematischen Koordinatenverbesserung zuzuwenden. Ein Polynom 2. Grades wird für jeden der 2 Bildträger eines analytischen Auswertegerätes genutzt, um die systematischen Fehler im Bereich der Variation von einzelnen Beobachtungen zu modellieren. Bezüglich der Stabilität des Instruments wird eine Anforderung formuliert. Solche Verfahren kännen auch bei anderen Geräten, wie zum Beispiel Bildscanner angewendet werden.

Notes: Photogrammetry is used extensively in British Coal Opencast to provide surface profiles of both new sites and existing sites. This paper will discuss the development of GPS within Opencast and its deployment as a tool to provide the ground control required for mapping. Comparisons with conventional equipment will also be made and relative cost effectiveness assessed. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On utilise largement la photogrammétrie dans British Coal Opencast, pour déterminer des profiles de surface, à la fois dans les sites nouveaux et dans les sites en cours. On examine dans cet article ľ emploi du GPS dans ces mines et son développement comme outil permettant ď obtenir les points ď appui sur le terrain nécessaires à la cartographie. On se propose defaire les comparaisons avec les équipements classiques et ďévaluer les avantages relatifs coût/efficacité. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Die Photogrammetrie wird bei den Britischen Kohlen-Tagebauen extensiv zur Beschaffung von Oberflächenprofilen sowohl bei Neuaufschlüssen als auch bei bestehenden Gruben eingesetzt. Im Artikel wird die Entwicklung von GPS und seine Entwicklung als Hilfsmittel zur Beschaffung der für die Kartenherstellung benötigten Paβpunkte diskutiert. Es erfolgen auch Vergleiche mit der konventionellen Ausrüstung und in bezug auf die relative Kosteneffektivität.

Notes: An investigation has been made into the feasibility of using a low cost GPS receiver fitted to a light fixed wing aircraft as an aid to flying parallel flight lines for block aerial vertical photography. Two cases were examined: (I) the pilot controlled the heading of the aircraft according to the indications on the course deviation indicator of the GPS receiver; (2) the autopilot, being connected to the GPS receiver, controlled the heading of the aircraft. The results obtained for both sidelap and endlap were equal to or superior to those obtained with a CCTV system. 〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn a mené une recherche sur la faisabilité du GPS comme aide au maintien du parallélisme des axes de prises de vues d'un bloc de photographies aériennes verticales, en utilisant un récepteur GPS bon marché fié a un avion léger. On a examiné deux cas: (i) celui ou le pilote a maintenu le cap de l'avion en suivant les indications de l'index de changement de route du récepteur GPS; (ii) celui ou c'est le pilote automatique qui, par une liaison au récepteur GPS, a maintenu le cap de l'uvion. Les résultats obtenus pour le recouvrement latéral et l'extrgmité des bandes se sont révélés égaux ou supérieurs ii ceux obtenus avec un systPme CCTV.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungEs wurde eine Untersuchung über die mögliche Nutzung billiger GPS-Empfanger, die in ein Kleinjlugzeug als Hilfsmittel zum Flug paralleler Bildstreifen für die blockweise Luftbildaufnahme eingebaut wurden, durchgefuhrt. Dabei wurden 2 Falle geprüft: (1) Der Pilot steuerte das Flugzeug entsprechend der Anzeige auf dem Kursindikator des GPS-Empfangers. (2) Der mit dem GPS-Empfänger verbundene Autopilot steuerte das Flugzeug. Die Ergebnisse sowohl für Querals auch Längsüberdeckung waren gleich oder besser als die mit einem CCTV-System erhaltenen.

Notes: The authors provide an account of current Directorate of Military Survey approaches to the provision of photocontrol by use of GPS and they pay special attention to the requirements of height control. 〈section xml:id="abs1-2"〉〈title type="main"〉SummaryGPS now provides us with a rapid method for determining plan and height for photogrammetric control directly over the points required by the photogrammetrist. By utilizing the slope of the geoid model, orthometric heights can be obtained to an accuracy of 0.15 m to 0.2 m. Surveys can be carried out quickly in all weather conditions and with none of the traditional terrestrial survey skills. Time, cost and manpower are greatly reduced. The plan accuracies are well within any requirements of the photogrammetrist and heights can be achieved to within 0.15 m to 0.2 m on test areas of UK. As photogrammetric height accuracy requires at best 1 m for plotting a 10 metre contour interval, heighting by GPS and the use of a geoid model solves the heighting problem.〈section xml:id="abs1-3"〉〈title type="main"〉Résumé Les auteurs fournissent un compte-rendu de la façon dont le Directorate of Military Survey aborde actuellement le problème de la fourniture de points ďappui photos avec ľemploi du GPS et prêterit une attention particulière à celui des points ďappui altimétriques.〈section xml:id="abs1-4"〉〈title type="main"〉Zusammenfassung Die Autoren geben einen Bericht über die gegenwärtigen Versuche beim Directorate of Military Survey zur Paβpunktbestimmung mit GPS, wobei sie den Anforderungen an die Höhenbestimmung besondere Aufmerksamkeit zollen.

Notes: The operational situation of precise airborne GPS positioning of camera air stations and its use in combined block adjustment for aerial triangulation is reviewed. The acceptance of systematic GPS errors, which occur especially with biased phase ambiguity solutions after loss of lock of signals in-flight, has motivated the method of additional linear GPS drift parameters which are to be solved in the combined block adjustment. It also implies that no absolute GPS co-ordinates are required and that the datum transformation is provided via a few ground control points. A great number of practical examples demonstrates that the method has been successfully applied within a wide range of photoscales and of block sizes. It has proved to be fully operational under various practical conditions. The high accuracy performance of GPS blocks and the economic benefit have been confirmed. It is particularly noticeable that the stationary receiver can be at a great distance, up to 500 km or more from the mission area. The conclusion is drawn that GPS supported aerial triangulation is ready to become standard. The potential improvement from dual frequency receivers and fast ambiguity solutions only enhances that conclusion. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On examine, dans cet article, le degréďopérationnalité atteint par le GPS aéroporté dans le positionnement précis des sommets de prises de vues des caméras aériennes, et son insertion dans la compensation par blocs en aérotriangulation. La possibilityéďerreurs systématiques dans le GPS, en particulier en cas de perte des signaux en vol, qui se manifeste par des ambiguïtés de phase et des biais dans les résultats, à conduit a introduire dans la compensation en bloc des inconnues supplémental s, traduisant une dérive linéaire du GPS. II en résulte qu'il n'est pas nécessaire de disposer de coordonnées GPS absolues et que quelques points ďappui sur le terrain suffisent à assurer les changements de coordonnées. On a utilisé avec succès cette méthode dans de nombreux essaispratiques comportant un large eventail ďéchelles de prises de vues et de tallies des blocs. On a pu ainsi mettre en évidence ľentière opérationnalité de cette méthode, dans des conditions réelles différentes. On a également confirmé la haute précision des résultats des blocs GPS et les avantages économiques de ce système. En particulier, il est tout à fait remarquable que le récepteur fixe puisse se trouver à une grande distance de la zone du lasé, 500 km ou plus. On peut en conclure que ľaérotriangulation appuyée sur le GPS est en train de devenir une méthode standard. Les améliorations possibles que peuvent apporter les récepteurs à deux fréquences et la résolution rapide des ambiguïtés, ne font que renforcer cette conclusion. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Die hochgenaue Kamera Positionierung durch GPS und ihre Anwendung für die Aerotriangulation wird zusammengefaβt dargestellt. Die Existenz systematischer GPS Fehler, wie sie inbesondere durch nur genäherte Phasen-Mehrdeutigkeitslösungen nach Signalabrissen im Flug verursacht werden, haben zu der speziellen Methode zusätzlicher linearer GPS Drift Parameter geführt, die in der kombinierten Blockausgleichung bestimmt werden. Ferner wird dabei die Datumtransformation mit Hilfe einiger weniger Paβpunkte bestimmt, d.h. es werden keine absoluten GPS Koordinaten vorausgesetzt. Mit einer groβen Zahl praktischer Beispiele wird demonstriert, daβ die Methode in einem groβen Bereich von Bildmaβstäben und Blockgröβen bereits erfolgreich angewendet wird. Sie hat sich unter den verschiedensten praktischen Bedingungen als voll operationell erwiesen. Dabei wurde die theoretisch erwartete hohe Genauigkeit der GPS Blöcke und ihre Wirtschaftlichkeit bestätigt. Besonders bedeutsam ist der empirische Nachweis, daβ der stationäre GPS Empfänger sehr weit, bis 500 km oder mehr, von dem Fluggebiet entfernt sein kann. Als Ergebnis wird empfohlen, die GPS gestützte Aerotriangulation als verfügbares photogrammetrisches Standardverfahren allgemein zu verwenden. Diese Schluβfolgerung wird durch die neuesten Entwicklungen von Zwei-Frequenz Empfängern und schnellen Mehrdeutigkeitslösungen, in die hohe Erwartungen gesetzt werden, nur noch bekräftigt.

Notes: A description is given of a heighting accuracy test carried out at Cartographical Services Limited on 1:2000 scale aerial photography. Premarked points, with ground surveyed heights, were established on a dual carriageway road near Worcester and photography was flown using a Leica RC20 aerial camera with EMC. Photogrammetric height measurement was carried out with both a Zeiss P3 analytical plotter and a Cartographic Engineering Limited/Carto Instruments AP190 plotter; respective r.m.s.e. accuracies of ± 25 mm and ± 30 mm were obtained. The new Cartographic Engineering Limited CP2 analytical plotter has subsequently been used for height measurement on similar photography and comparable accuracy has been achieved. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On présente un essai de précision altimétrique, effectué par la Société“Cartographical Services” de Southampton, sur des photographies aérienne àľéchelledu 1:2000. On a utilisé des points pré-balisés, repartis sur une route à double voie près de Worcester, et dont ľaltitude a été déterminé sur le terrain. La prise de vue a été fait avec une caméra Leica RC20 munie ďun système de compensation du filé longitudinal. On a effectué les déterminations photogrammétriques des altitudes en utilisant à la fois un restituteur analytique Zeiss P3 et une restituteur AP190 de la Société“Cartographic Engineering/Carto Instruments.” On a obtenu comme erreurs moyennes quadratique les valeurs de ± 25 mm et ± 30 mm respectivement. On a enfin utilisé le noveau restituteur analytique CP2 de la Société“Cartographic Engineering” pour ces déterminations altimétriques et ľon a obtenu une précision comparable. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Es wird ein Versuch zur Bestimmung der Höhengenauigkeit, der beim Cartographical Services Ltd. in Southampton für den Bildmaβstab 1:2000 durchgeführt wurde beschrieben. Signalisierte Punkte, deren Höhen im Gelände bestimmt wurden, wurden aufeiner Doppelfahrbahn in der Nähe von Worcester angeordnet undmit einerLeica RC20 mit EMC aufgenommen. Die photogrammetrische Höhenbestimmung erfolgte mit einem analytischen Auswertegerät P3 von Zeiss und einem AP 190 Plotter von Cartographic Engineering Ltd./Carto Instruments. Dabei wurden mittlere Fehler von ± 25 mm bzw. ± 30 mm erhalten. Das neue analytische Auswertegerät CP 2 von Cartographic Engineering Ltd. wurde danach für Höhenmessungen bei ähnlichen Luftbildern genutzt, wobei vergleichbare Genauigkeiten erreicht wurden.

Notes: This paper describes a method for modelling the SPOT satellite imaging process using a single Ground Control Point (GCP) and for extracting ground planimetric information. Satellite position is derived using the collinearity condition equations. Initial orbit is obtained from the given ephemeris data and refinement is carried out using an iterative least squares solution. Attitude variations are taken into account by fitting a third order polynomial in time to the attitudes derived from the ephemeris by integration. After refining the satellite position, planimetric co-ordinates can be derived using the collinearity equations with an accuracy of up to 38 m in latitude and 52 m in longitude (average of the r.m.s. errors from two tests) when the GCP used for modelling is obtained from the 1:50 000 scale map. These figures include the measurement errors as well as the modelling error. It has been found that the method is not sensitive to the location of the GCP used for modelling. Résumé On présente dans cet article une méthode de modélisation du traitement des images du satellite SPOT ne faisant appel qu'à un seul point ďappui au sol et permettant ďextraire des informations planimétriques. On obtient la position du satellite à partir des équations traduisant la condition de colinéarité. On part ďune orbite initiale issue des données fournies par les éphémerides, et on ľameliore par une résolution itèrative, basée sur les moindres carrés. On tient compte des variations ďattitude par ľintermédiaire ďun polynome du troisième ordre fonction du temps et correspondant aux attitudes dérivées des éphémérides par intégration. Une fois obtenue la position définitive du satellite, on peut tirer les coordonnees planimétriques des équations de colinéarité avec une précision qui atteint 38 m en latitude et 52 m en longitude (valeurs moyennes des erreurs moyennes quadratiques rèsultant de deux essais), lorsque le point ďappui au sol utilisé dans la modélisation provident de la carte au 1:50 000. Ces chiffres incluent les erreurs de mesure ainsi que ľerreur de modélisation. On a trouvé que la méthode nétait pas du tout sensible à la position qu'occupait le point ďappui au sol utilisé dans le modélisation. 〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Im Artikel wird ein Verfahren zur Geländemodellierung des SPOT-Abbildungsprozesses unter Verwendung eines einzelnen Geländepaβpunktes (GCP) und zur Ableitung planimetrischer Informational beschrieben. Die Satellitenposition wird mit Hilfe der Kollinearitätsgleichungen beschrieben. Die Näherungswerte für die Bahnkurve werden aus gegebenen Ephemeriden bestimmt, die durch einen iterativen Prozeβ nach der Methode der kleinsten Quadrate verbessert werden. Veränderungen der Bahn werden rechtzeitig durch Anpassung mit einem Polynom 3. Grades an die aus den Ephemeriden abgeleitete Bahn durch Integration angepaβt. Nach Verbesserung der Satelliten-position können die Lagekoordinaten mit Hilfe der Kollinearitätsgleichungen mit einer Genauigkeit bis zu 38 m in der Breite und 52 m in der Länge (Mittelwert der mittleren Fehler aus 2 Versuchen) bestimmt werden, wenn der Paβpunkt (GCP) aus einer Karte 1:50 000 entnommen wurde. Dabei ist der Meβfehler ebenso wie der Modellierungsfehler enthalten. Es zeigte sich, daβ das Verfahren nicht empfindlich ist in bezug aufdie Lage des zur Modellierung benutzten Paβpunktes.

Notes: The construction of a composite index is described to rank U.S. metropolitan areas for educational attainment. The suggested methodology departs from traditional rank sum methods in that this approach utilizes data resulting in a continuous scale, whereas in the rank sum method, no use is made of the actual values of the data, but merely their rankings. The proposed index circumvents several practical problems because the numbers generated are metric measures allowing the use of arithmetic and statistical operations. Data used are pupil/teacher ratio, an effort index, and academic options in higher education. Comparisons are made across areas by population size and by geographic region.

Notes: Using data from the National Conference of State Legislatures, this paper examines the state budget stabilization funds of Indiana, Iowa, Missouri, Michigan, Minnesota, Ohio, and Wisconsin. Unlike previous research, this paper examines the movement of the fund balances over time (between 1983 and 1991), to see how the fund balances move in relation to a number of indicators of state fiscal health. The results of this research show that the use of these funds varies significantly among the states as does the level of funding and therefore the ability of the funds to serve as an effective tool for counter-cyclical state fiscal policy.

Notes: Book reviewed in this article:Agriculture, Environment, and Health: Sustainable Development in the 21st Century. Vernon W. Ruttan, Editor.Managing Water as an Economic Resource. James Winpenny.Trials of Transition: Economic Reform in the Former Communist Bloc. Michael Keren and Gur Ofer, Editors.Tower Block: Modern Public Houslng in England, Scotland, Wales and Northern Ireland. Miles Glendinning and Stefan Muthesius.Capital and Communities in Black and White: The Intersections of Race, Class, and Uneven Development. Gregory S.Restructuring for Innovation: The Remaking of the U.S. Semiconductor Industry. David P. Angel.Technopolis: High-Technology Industry and Regional Development in Southern California. Allen J. Scott.

Notes: The results of this study confirm the expected positive relationship between economic development agency spending and employment growth among the states. Furthermore, it is concluded that past studies, by failing to control for state economic development agency spending in estimated regression equations, have underestimated the negative impact of personal taxes on employment growth.

Notes: This paper explores the impact of new technology adoption upon the market performance of small industrial firms. Survey data from a six-sector sample of Western New York manufacturers are presented. The results suggest a positive relationship between new technology adoption and growth of exports, value-added, and total sales. A central finding of the study is that flexible manufacturing systems (FMS) confer different types of technical and commercial advantages across sectors. Two broad groups of process innovators are identified: (1) those that adopt new technology primarily to cut unit costs; and (2) those that aspire toward greater production flexibility. The paper concludes with a brief discussion of the regional development implications that flow from the empirical results.

Notes: This paper presents results of a hierarchical, fixed-question survey that sought responses about flexible machining cells, flexible labor cells, and concurrent changes in plant operations among nonelectrical machinery manufacturers in Illinois, Indiana, Michigan, Ohio, and Wisconsin. General results indicate that the majority of firms in the American Midwest do not possess flexible manufacturing capability. Of those that do possess this capability, most adopted flexible labor cells prior to adopting flexible machining cells. These cells are small, employing relatively few workers and producing a limited line of products. While the adoption process has been plagued with training, scheduling, and integration problems, most plant managers are pleased with the performance of their flexible manufacturing cells. Management has been reluctant to break out of traditional relationships with suppliers, to trim levels of management and to explore strategic alliances with competitors. Survey results are disaggregated by year, size, positon-in-organization, and by union affiliation.

Notes: Book Review in This Article:POSTMODERN CONTENTIONS: EPOCHS, POLITICS, SPACE. Edited by John Paul Jones III, Wolfgang Natter, and Theodore Schatzki.RESTRUCTURING HEGEMONY IN THE GLOBAL POLITICAL ECONOMY: THE RISE OF TRANSNATIONAL NEW-LIBERALISM IN THE 1980s. Edited by Henk Overbeek.THE DEVELOPMENT PROCESS IN SMALL ISLAND STATES. Edited by Douglas G. Lockhart, David Drakakis-Smith, and John Schembri.DEFENSE SPENDING AND ECONOMIC GROWTH. Edited by James E. Payne and Anandi Sahu.URBAN FINANCE UNDER SIEGE. Edited by Thomas R. Swartz and Frank J. Bonello.STATE & RESERVATION: NEW PERSPECTIVES ON FEDERAL INDIAN POLICY. Edited by George Pierre Castile and Robert L. Bee.

Notes: Despite the fact that nonemployment income makes up approximately one-third of all personal income, its impact on local area economies has not been closely examined. This study uses Michigan county data to examine the impact of nonemployment income on nonbasic income over a twenty-seven-year period. This impact is compared to the impact of basic income by employing regression analysis to estimate comparative multiplier effects for both types of income. Nonemployment income is found to have a significant impact on nonbasic income, particularly in metropolitan and nonmetropolitan urban counties, where its impact appears to be stronger than that of basic income.

Notes: This paper examines spatial-temporal trends in the international system of corporate banking centers. It is evident that the largest corporations locate their headquarters in a formal national decision-making hierarchy and that national and regional nodes within this hierarchy house the headquarters of major banks. Initially these banks link clients internally. However, as domestic corporations evolve into transnationals, banks follow their customers overseas and establish foreign headquarters. The results of the study indicate that, until 1975, American banking corporations and their financial centers dominated global banking. Since then other countries, most notably Japan and Germany, have successfully challenged this hegemony, while others like the United Kingdom and Canada have been in relative decline. The 1980s witnessed a new era of international coordination of the world's largest industrial countries. Canada, for example, opened its doors to international banking, joined the G-7, and presently is linked to the world's major banking centers.

Notes: Over the past fifteen years, legislative, regulatory, and technological changes have occurred which have redefined the concept of a “local” bank deposit market. This study employs an interest rate covariability model to evaluate the geographic extent of bank retail CD markets. Classifying deposits according to both size and maturity, a total of four markets are analyzed using yield data for six major state banking areas. The evidence presented for all four cases supports the view that significant, though not perfect, integration exists. The principal finding is that the geographic scope of retail CD markets is inversely related to both size and maturity.

Notes: The success of economic development initiatives in achieving a significant and sustained improvement for a target area is strongly influenced by the size of the local multiplier. New economic activity is generally site specific and the proportion of spending and re-spending that generates local multiplier effect will vary with the hierarchical level of community in which the activity is located. Leakages in the form of outshopping by community residents and expenditures in the community that constitute payments to agents outside the home community are estimated for communities in six functional levels that, combined, represent the complete trade center hierarchy in Saskatchewan. The resulting multipliers are found to vary with functional level, with the smallest communities having the smallest multipliers. When rural areas are being targeted for economic development, more rural economic activity can be generated by focusing on relatively large rural communities.

Notes: Hong Kong, Singapore, Korea, and Taiwan (the Asian newly industrialized economies [NIEs]) were the economic success stories of the 1970s and 1980s. While there are a number of competing explanations for their rapid growth, some focusing upon the process of export-led development, the Asian NIEs face a more hostile global competitive environment than heretofore acknowledged. Their competitiveness in labor-intensive and traded-goods manufactured industries has been undermined by new competitors including the ASEAN countries of Indonesia, Malaysia, Thailand, and the Philippines, as well as China. With new competitors, the rise of trading blocs, and the shrinkage of export surpluses (over imports) it is doubtful if the NIEs will be able to sustain past rates of growth over the coming years. The capacity to adjust efficiently to changing circumstances has become a vital determinate of long-term growth of the NIEs. Whatever the virtues of past state-based industrial policies, restructuring is now a very important part of the life of firms in the NIEs’labor-intensive industries. Moreover, the significance of these industries in each of the NIEs has been undercut by the growing importance of the global finance industry and its attendant political economy.

Notes: The paper presents a model of worktrip length for rural nonmetropolitan resident women. We find that some factors important in constraining the length of urban women's commute, such as linking worktrips with household-related trips. are less relevant in a rural setting. We also find that women working in non-feminized occupations, women receiving employer-provided health benefits, and women with better transportation resources, tend to have longer worktrips.

Notes: This paper presents a historical perspective of growth of the Mexican automobile industry, focusing on the changing position of Third-World producers within the global motor vehicle industry. Both the impact of Mexican government policies directed toward increasing international competitiveness and that of adjustments made by transnational corporations to changes in technology and production methods are reviewed. Finally, a demand function that relates the proportion of the industry output that is exported to relative producer prices, Mexican and U.S. income, and government policy variables is estimated. The results of that analysis are consistent with the hypotheses that Mexican automotive sector exports are significantly related to (1) relative Mexico/U.S. producer prices, (2) income in the United States, and (3) changes in Mexican government export promotion policies initiated in 1983. These specific results, coupled with the global changes taking place in the industry, lead to the conclusion that Mexico can be expected to continue on its course toward fuller integration into the world motor vehicle industry as a producer of both finished vehicles and parts. While this would be a probable scenario even in the absence of the North American Free Trade Agreement, the Agreement is likely to accelerate the growth of internationally competitive automotive sector production in Mexico.

Notes: Existing studies of convergence across jurisdictions of a nation have focused on developed economies. A key assumption underlying regional convergence is geographical factor mobility, and in a developed economy, mobility is facilitated by low transportation costs. By the same token, convergence in a less-developed economy may be impeded by the absence of a well-developed transportation infrastructure. We examine the rate and industrial composition of economic convergence in a neighboring less-developed country (LDC), Mexico, to examine how it might have differed from the U.S. experience.We find evidence of stronger convergence in Gross State Product per capita in Mexico relative to existing estimates of U.S. convergence. Further, while manufacturing activity has been found to be a primary source of convergence in the U.S., we find weaker evidence of convergence of manufacturing activity in Mexico. On the other hand, industries such as hotels and transportation were found to be significantly influential in regional convergence in the Mexican economy.

Notes: Book reviewed in this article:Institutional Incentives and Sustainable Development: Infrastructure Policies in Perspective. Elinor Ostrom, Larry Schroeder, and Susan Wynne.The Colonizer's Model OF THE World: Geographical Diffusionism AND Eurocentric History. James Blaut.The Age OF Migration: International Population Movements IN The Modern World. Stephen Castles and Mark J. Miller.Environmental Problems In Eastern Europe. F.W. Carter and D. Turnock, Editors.China's Economic Reform: Administering The Introduction Of The Market Mechanism. George Totten and Zhou Shulian.Regional Advantage: Culture and Competition in Silicon Valley And Route 128. AnnaLee Saxenian.

Notes: This paper establishes the concept of production system as an analytical framework to embrace recent industrial changes. Five dimensions of production system changes are posited. A case study of the Korean consumer electronics sector shows that the companies have experienced diverse patterns of changes, but these changes are generally related to plant location, ownership, export orientation, and company size.

Notes: This paper focuses on restructuring in eleven first-tier suppliers in the South Wales motor components sector and examines the influence of production politics, including plant-local labor market relations, on the implementation of flexible manufacaturing during the 1980s. Although industrial geographers have recognized the role of recruitment and training in the restructuring of the spatial division of labor they have tended to focus primarily on the role of new firms operating at “green field” sites and view this process as functional to the needs of capital. However, the argument of this paper will be that while new forms of work organization are influenced by the technical and commercial possibilities of new technology and markets, the form of work organization cannot simply be “read off” from the macro-economic level, but will be partially determined by existing spatiallyuneven social relations of production.

Notes: Institutions matter to economic development—particularly to the process of economic transformation. New technologies and new ways of organizing economic activity do not emerge in a vacuum, but bear the imprint of institutional arrangements. Economic transformation thus entails institutional adaptation as well as technological change—the emergence of new ways of organizing production or production systems and new sets of social and economic relationships which provide the institutional context for economic growth and development. Just as importantly, new institutional arrangements do not emerge tabula rasa, but reflect the legacy of old social and institutional forms. Given particular social and institutional legacies, different societies adapt differently to economic transformation. This article employs a theoretically-informed comparative examination of postwar Japanese capitalism to explore the critical role played by institutions in the process of economic transformation.

Notes: This paper presents a contemporary survey and synthesis of research on the regional dimensions of technology and competitiveness and explores ways in which technological change has influenced industrial restructuring in U.S. regions. Neoclassical models of regional growth are judged to be seriously wanting in their treatment of technological change. Industrial organization theories such as product/profit cycles, best-practice firms, and flexible specialization have proven to be more illuminating. However, the task remains to integrate technology as a core element in a geography of production and regional economic change that includes both global strategic decision-making of companies and the viability of plants in particular regional settings. Although the federal government as sponsor and procurer of technology has contributed significantly to regional industrial restructuring, the prospects for state and local governments to facilitate technological change appear to be very limited.

Notes: A case study of the Hong Kong watch industry demonstrates the adaptive flexibility of labor-intensive industrial clusters. The study describes the evolution of industry in Hong Kong, and highlights the unique attributes of the country's economic history which have influenced the structure of production systems in the country. Focusing on the role of global competition, the case study identifies the constraints posed by a labor-intensive flexible production system in the face of continuous technological change in the industry.

Notes: There is little consensus in the development literature on whether it is supply explanations such as competitiveness levels, or, the external demand structure which drive the link between exports and economic growth. This paper attempts to reconcile the polarization of the aforementioned viewpoints by examining the effects of both world demand and a country's competitiveness in exports on the relationship between export growth and economic growth. The results indicate that only developing countries which are highly competitive and which also face relatively favorable external demand for their exports experience above-average growth. Weak external demand reduces the positive effects of exports on growth substantially but may be offset by high levels of competitiveness in trade. The results imply that both regional and Third World growth studies on the link between exports and economic growth would profit more from integrating both supply as well as external demand explanations rather than succumb to one of the two viewpoints.

Notes: Input-output models are frequently used to estimate impacts, benefits or damages from some event. These analytic models and the questions they are designed to answer are usually based on political definitions of regions. However the true impacts propagate according to the actual spatial pattern of the regional economy. Because of the divergence between the political regions used for analysis and the economic regions on the ground, the economic impacts which spill over political boundaries can sometimes become analytically important. This paper applies these concepts to a case study of allocating irrigation water from the Pecos River in Texas and New Mexico. The U.S. Supreme Court has ruled that New Mexico used water belonging to Texas. Our analysis suggests that the spillover benefits to Texas from New Mexico's use of the water might equal or exceed the benefits which Texas would have gotten from using the water itself. Texas might be better off because New Mexico took its water.

Notes: Book reviewed in this article:The Structure of a Modern Economy: The United States, 1929–89. by Kenneth E. Boulding.Inequality Reexamined. Amartya Sen.Work in the Fast Lane: Flexibility, Divisions of Labor, and Inequality in High-Tech Industries. Glenna Colclough and Charles M. Tolbert II.Persistent Poverty in Rural America. Rural Sociological Society Task Force on Persistent Rural Poverty.Deep Disagreement in U.S. Agriculture: Making Sense of Policy Conflict. by Christopher Hamlin and Philip T. Shepard.Dividing the Waters: Governing Groundwater in Southern California. William Blomquist.Trading Industries: Trading Regions. Helzi Noponen, Julie Graham and Ann Markusen, editors.Trading in a New World Order: The Impact of Telecommunications and Data Services on International Trade in Services by Bruno Lanvin, editor.Exports and Local Development: Mexico's New Maquiladoras. Patricia A. Wilson.Latin America's Turnaround: Privatization, Foreign Investment, and Growth. Paul H. Boeker, editor.The Dynamics of Liberalization: Tanzania and the IMF by Horace Campbell and Howard Stein, editors.Keynes General Theory of Interest: A Reconsideration. Fiona C. Maclachlan.Microcomputer-Based Input-Output Modeling: Applications to Economic Development. Daniel M. Otto and Thomas G. Johnson, editors.

Notes: . .The growth of health maintenance organizations (HMOs) commonly has been viewed as a “procompetitive” change in the structure of the health care delivery system. Because HMOs collect a prepaid fee from subscribers, they serve a dual role as insurers and providers of health care. While HMOs may have competed directly with conventional insurance plans, their effect in health care markets is potentially quite different. A multisector spatial equilibrium model, which incorporates the optimizing behavior of consumers, independent fee-for-service(FFS)providers, and a centralized HMO, is used to explore the effects of an exogenous shift in market structure away from FFS delivery toward the provision of seivices by the HMO. As more physicians are diverted from FFS practice to enter the HMO, both the HMO membership fee and prices in the FFS sector tend to rise. This pattern is consistent with empirical trends in the United States during the 1980s where, despite the rapid growth in HMOs and other forms of prepaid care, both FFS prices and HMO membership fees have risen sharply.

Notes: . This paper analyzes the implications of an exogenous shift in relative prices for an economy that suffers from urban unemployment, as well as uncertainty, in the agricultural sector. Among other things, we show that with agricultural uncertainty, an exogenous shift in relative prices will lower agricultural profit. This result is in sharp contrast with the conventional case of risk-neutrality or certainty where agricultural profit is unaffected by changes in the terms of trade.

Notes: This paper examines the interface between port cities, urban regions and their transportation systems with respect to Singapore. The development of the regional Singaporean transactional space incorporates the province of Johor in Malaysia and the Riau islands in Indonesia, with the resulting spatial pattern and linkages forming an Extended Metropolitan Region (EMR). An EMR spatial model is presented in which transportation is a key factor. This model explains four processes of territorial development — densification, dissemination, extension and contraction. Densification is a process of spatial accumulation of economic activities within an area and aims at higher levels of productivity. Dissemination is a spatial relocation of unproductive economic activity towards productive areas. Extension is a space/time collapse enabling economic activities to extend over a large territory while maintaining low distribution costs. Contraction is a rationalisation of distribution systems facing growing transportation costs and competition from other systems. Based on the framework provided by the spatial model and available evidence, an assessment of transportation and territorial development in the Singapore EMR is undertaken. The analysis underlines the role of Singapore as a regional transhipment centre and its maritimefland interface function.

Notes: Although the last 40 years have witnessed enormous changes within the Third World, many of these have been uneven in their intensity and impact. Indeed, the widening differences between developing countries beg the question as to whether they constitute a cohesive collectivity.This essay makes a comparison between the tropical Third World of the 1950s and that of the 1990s. In many ways the former was much more set and predictable in its relationships and structure than today. However, the changes which have taken place over the last 40 years have not always been to the advantage or lasting benefit of the majority of people in the Third World. A realistic appraisal of future problems and how these might be addressed is thus a central theme of this discussion.

Notes: The development of physical geography in South Asia has generally followed the British and European trends. Diverse themes from denudational chronology to palaeoflood geomorphology have attracted the attention of geomorphologists, particularly in the last 25 years. In addition, geographers’ interest in climatology and biogeography became pronounced during the 1980s. Major methodological shifts in the late 1960s in the west have affected geographical studies in South Asia. These shifts include the use of methods of quantification, remote sensing data, and the increased importance of field and laboratory studies. The second notable aspect in recent times is the accelerating interest amongst physical geographers in environmental studies and the applied aspects of the discipline as well as an increased interaction with scientists in cognate fields. An attempt is also made to identify the key research themes that will interest physical geographers in the near future.

Notes: Our knowledge regarding the physical geography of Southeast Asia is incomplete to a surprising extent. This paper reviews the past research, describes the ongoing work, and attempts to identify the future trends. Coverage of such a large area, even for the last 25 years, requires study of publications in several languages and coping with literature which is not easily available. Therefore certain topics. which are prominent in current research and likely to remain so in the future were chosen and reviewed in detail. Such topics include studies related to active plate margin features; the Pleistocene in Southeast Asia; erosion and sedimentation rates; rainforest; river systems; karst in Southeast Asia; coastal geomorphology; and the urban environment.Environmental studies are rapidly gaining importance chiefly because of (a) the destruction of the natural vegetation and the associated loss of biodiversity and (b) the growing problems due to accelerated erosion and sedimentation This trend is likely to continue with accelerated destruction of forests, development of coastal areas, and urbanization of the landscape The direction of research in physical geography of Southeast Asia has been determined by a combination of individual research interest, governmental priorities, and international expectations

Notes: This paper attempts to reconcile two major conflicting viewpoints regarding the effects of export expansion on economic growth. The first, export optimism, looks to supply factors such as international competitiveness with the view that a favourable export performance results in significant economic growth for a country. The second, export pessimism, argues that exports only contribute significantly to a country's economic growth when the external demand is favourable. Using the Expansion Methodology, the paper shows that the effects of demand and supply factors on the relationship between export growth and economic growth are about the same. The results suggest that while unfavourable demand weakens the aforementioned relationship, tropical countries can offset this by being competitive in their exports. They also caution against excessive weight being given to export-promotion by export optimists as the exports-growth relationship weakens considerably when the external demand falls.

Notes: In the 1950s, few people had travelled widely through different parts of the tropics and interpretations on tropical landforms, soils, vegetation and climate largely rested on impressions gained from residence or long sojourns in particular tropical countries. Most academic geography on the tropics was then written by expatriates and lacked the perspective gained from long experience of tropical regions. Particular problems of understanding arose as people attempted to extrapolate from one part of the tropics to another. Since then, understanding has advanced enormously, largely through the efforts of tropical scientists working in their own institutions and through the greater technological ability to study tropical lands both remotely and through easier field access. The establishment of a number of field stations, aimed primarily at the biological sciences, but also facilitating the work of geographers, has been a major stimulus to this effort. Concerns over practical issues, particularly local development and global climatic change have prompted new avenues of research, many of which have been assisted by the great increase in data collection in tropical countries. For the future, South-South dialogue between tropical physical geographers is needed to improve their ability to ask meaningful questions so that they can contribute to teach the rest of their discipline more about serious applied and applicable geography.

Notes: This paper reviews the articles published on human geography in the Journal since its inception, and focuses on the contributions made in the major fields of research. In the earlier years of the Journal, the themes of tropical agriculture, population and settlement geography, and historical geography were particularly strong, as was a concern with human-environment relationships. Over the years, articles on urban and regional planning, transport and communications, tourism and recreation, and in social geography were also published, reflecting the increasing spread of themes covered. One of the most significant dimensions of change in the Journal has been a shift from a descriptive orientation of the articles to one emphasizing theory development and evaluation.

Notes: The first recorded information about living fresh water diatoms on an ice-wedge furrow is presented. One sample has been analysed and two species, Cymbella aequatis and Tabellaria flocculosa, formed almost half of the diatom population. Some rather rare species for the Canadian Eastern Arctic were identified: Fragilaria constricta, Eunotia lunaris, Eunotia microcephala, Pinnularia gibba, Anomoeoneis zellensis, and Cymbella aspea. Of the 37 species identified, most are common elsewhere in the Arctic.

Notes: The copepods Limnocalanus macrurus G. O. Sars and Eucyclops serrulatus (Fisch.) and the ostracode Cytherissa lacustris (G. O. Sars), hitherto unknown on Spitsbergen, were found in Lake Rewatnet, the last species also in Lake Svartvatnet. Samples from parthenogenetic populations of C. lacustris showed a complete lack of electrophoretically detectable variability at four enzyme-encoding loci, two of which are highly variable in mainland populations. However, morphological variation in the carapace length and nodation was no less than in the mainland populations. The carapace valves of C. lacustris do not preserve well in the sediments of Rewatnet.

Notes: A model is presented that performs spectral deicing of mixed pixels in satellite images of glaciated areas. The model was tested in Northern Victoria Land, Antarctica. For this region we assumed that pixels could be grouped in two broad categories representing pure ice and pure rock. Naturally mixed ice and rock pixels are present in satellite images; these were recomputed to separate the spectral component related to the rock fraction. We used Landsat TM images as input data and aerial photographs, maps and field surveys as reference data. By making use of sample populations of pixels corresponding to pure ice and to pure rock groundels (i.e. ground elements, the ground portions corresponding to each pixel), we detected the linear correlation between pairs of bands and selected the two most suitable bands. For every pixel falling between the correlation lines of the two categories, the rock fraction in the corresponding groundel was computed. This fractional value was then used to perform the automatic deicing process with which the DNs of the selected mixed pixels were recomputed. In the utilised Antarctic image, this process increases about 2.7 times the number of pixels in the pure rock category, allowing the production of enhanced images and, as a side product, a thematic map of rock percentage in the groundels.

Notes: A series of sensitivity analyses using dielectric, mixture and microwave scattering models is presented. Data from the Seasonal Sea Ice Monitoring and Modeling Site (SIMMS) in 1990 and 1991 are used to initialize the models. The objective of the research is to investigate the role of various geophysical and electrical properties in specifying the total relative scattering cross section (ρ′′) of snow covered first-year sea ice during the spring period.The seasonal transition period from the Winter SAR scattering season to Early Melt was shown to signal a transition in dielectric properties which caused the snow volume to become a factor in the microwave scattering process. The effect of the thermal insulation of a snow cover on sea ice was shown to be significant for both ε′ and ε′′. Higher atmospheric temperatures caused proportionally greater changes in the dielectric properties of the sea ice at the base of the snow cover. Model ρ0 was computed for a range of sensor, sensor-earth geometry, and geophysical properties. In the Winter season the surface roughness terms (ohand L) were shown to have a significant impact on ρ0 when the ice surface was the primary scattering mechanism. Once the snow cover began to warm and water was available in a liquid phase, the ice surface became masked because of the decrease in microwave penetration depths. During this period the water volume variable dominated ρ0, both from its impact on ρv0, and due to its control over the dielectric mismatch created at the air/snow interface.

Notes: Multi-temporal satellite images, field observations and field measurements were used to investigate the mechanisms by which sea ice melts offshore from the Mackenzie River Delta. Satellite data recorded between April and August 1986 were corrected to a map projection and calibrated such that albedo and temperature values could be compared. Three stages in the melting of sea ice were identified: flooding (overflows), insolation and melting by warm river water. The albedo values of overflows were as much as 1/7 that of ice values while the albedo of ice decreased by 1/3 over the summer. Approximately two weeks after the overflows develop, sea surface temperatures rise as the river-discharge peaks and becomes the dominant source of energy. By this process, ice removal in the delta regime is initiated two months earlier than adjacent coasts with minimal runoff. However, the net result is only a two-week acceleration of ice removal in the delta region.

Notes: NOAA-AVHRR satellite data have been used for a multi-year analysis of the seasonal variation of snow cover on the peninsula of Jameson Land located from 70°30′N to 72°N on the eastern coast of Greenland. Monitoring programmes for muskoxen and geese populations in Jameson Land wert started in the early 1980s to assess the impact of oil exploration in the area. This study was conducted to provide snow cover data to the wildlife monitoring programmes because snow cover is an important factor which can affect the numbers and distribution of muskoxen and other wildlife in the area.Snow cover mapping is based on the geometric correction and radiometric calibration of each satellite scene before the visual bands are corrected for the terrain-effects and high solar zenith angle by using a simple radiation model. The atmospheric effect on the thermal infrared bands is corrected by using the “split-window” method. An automatic filtering routine with empirically determined thresholds is used to determine cloud-and haze-covered areas before the snow cover is computed from a linear expression using albedos of bare ground and full snow cover. By combining the satellite information with ground measurements and a digital terrain model, both the spatial distribution of snow cover and the total snow cover depletion can be obtained.The method makes it possible to analyse the variation in regional and seasonal snow cover in wildlife habitats. The variation in snow cover depletion has been analysed in five subareas in the muskox area, and the results indicate that the snow cover pattern is an important factor which influences muskox calf crop and regional distribution of the muskox population. The method has proved useful for monitoring the duration of snow cover, and its application ought to facilitate the future study of wildlife habitats in extensive alpine and arctic areas.

Notes: Peculiarities in the intra-annual variations of 03, N20 and CH4 in the middle and upper stratosphere are analysed by different methods for the middle and polar latitudes of the Northern and the Southern hemispheres. In the middle stratosphere the phase of the O, annual harmonic shifts in the Northern Hemisphere from polar to lower latitudes, while in the Southern Hemisphere the downward shift is exhibited. The phase of the NiO annual harmonic shifts to the poles both in the Northern and Southern hemispheres, but in the Northern Hemisphere it is almost vertical with the horizontal spreading, while in the Southern Hemisphere the phase propagation has a remarkable downward component. The most similar shifts of the phase of the annual harmonic in the middle stratosphere of both hemispheres are exhibited for the CII” content in the middle and high latitudes. Remarkable differences are noted between the intervals with the increase of mixing ratios in the annual cycle at different latitudinal belts. In particular, these intervals are large in subtropical stratosphere, with a shorter and steeper decrease of the mixing ratios. The general decrease of these intervals is exhibited from middle to polar latitudes. The striking difference in temporal variations of the species exists between the northern polar and middle latitudes, where the month-to-month changes of the species are often opposite each to other. These peculiarities and interhemispheric differences are associated with the different stratospheric dynamics of the Northern and Southern hemispheres, particularly with different regimes of planetary wave activity in the northern and southern extratropical latitudes.

Notes: A time series of ERS-1 SAR images is used to estimate ice drift in the Fram Strait January-March 1992 (the ERS-1 mission first ice phase). The images all cover the same area. The sampling interval is three days. The paper shows examples of estimation of ice drift and divergence from this image time series. Divergence is an important quantity in order to estimate ice production and hence mixing of the ocean water masses.A reference configuration of ice points is defined for each image. These ice points are identified in the successive image giving a set of point pairs. These point pairs are input for statistical analysis.Upward looking sonars (ULS) and current meters are moored below the scene. A combination of the SAR derived dynamics and the ULS derived ice thickness series will give opportunities to estimate ice mass flux into the Greenland Sea, and to improve ice classification algorithms.

Notes: Sea ice charts produced using spacebornc passive microwave observations are used on routine basis at several ice forecasting centres and during sea ice research campaigns. The capability of passive microwave sensors to monitor the earth, regardless of cloud cover or daylight, and the 1400 km swath width (SSM/I) make these sensors well suited not only for ice forecasting but also for providing information needed for planning northern oceanic routes. The retrieval of sea ice parameters is carried out by utilizing 37 and 19 GHz brightness temperatures measured by Special Sensor Microwave Imager (SSM/I) on the Defense Meteorological Satellite Program (DMSP) platform. The ice type identification uses a-priory established signature brightness temperatures for each ice type. The algorithm generating the sea ice information contains some climatological information on the weather dependence of the observed brightness temperature. A comparison between passive microwave (SSM/I) retrieved ice parameters and ice maps from the Norwegian Meteorological Institute (DNMI) indicates that the weather correcting procedure within the algorithm may need regionalized input. The correlation of variability of the observed brightness temperatures with the weather changes has to be derived prior to introducing any corrections to the existing algorithms. The observed brightness temperatures contain information not only about the ice surface but also the atmospheric contribution. One of the crucial tasks is to establish a technique for flagging changes on the ice surface in order to segregate them from the atmospheric influence on the passive microwave signal. To obtain more knowledge about the effects of regional weather on the retrieval of sea ice parameters, local climatological information from DNMI has been compared with the SSM/I ice charts. This paper focuses on the outcome of this comparison and how regional atmospheric information can be used in the retrieval of sea ice information from passive microwave data.

Notes: Digital image analysis and SPOT XS satellite data recorded on 1 August 1991 were used to monitor vegetation in the border region between Enontekio municipality, Finland, and Kautokeino municipality, Norway. A supervised classification on the red wave length channel was undertaken using training areas for maximum likelihood classifier to produce seven spectral land cover classes. The classification revealed great differences in vegetation between Finland and Norway. The largest difference was the lack of Cladinalichens on the Finnish side of the border. The area on the Finnish side is used for grazing all year round, while the area on the Norwegian side is a winter range only. According to official data for the local reindeer population, the average annual grazing pressure (head/area/time) is higher on the Norwegian side of the reindeer fence. The Finnish grazing practice is believed to have a detrimental impact on the vegetation, and has lead to pasture land degradation.

Notes: The two methods suited for mapping the vegetation of remote inaccessible terrain were compared in terms of their ability to reproduce and distinguish predefined vegetation classes, the appropriateness of their different spatial resolutions to the same end, and their cost-effectiveness. The study was carried out in Jameson Land, East Greenland (70° 30′N to 72°N). The vegetation had previously been classified and mapped by the use of false colour infrared aerial photos in the period 1982–86. The resultant vegetation maps had been drawn on aerial photo overlays at a scale of 1:25, 000.SPOT data from 8 September 1986 and Landsat TM data from 10 August 1987 were used. A supervised classification of the combined satellite data was made using a maximum likelihood algorithm. A vegetation map was produced which accurately plotted 9 of the dominant vegetation classes and 4 non-vegetation classes. The two mapping methods were then compared. The satellite-based method was found to be inadequate for the mapping of vegetation classes which occur in very small vegetation patches. The photo-based mapping had better potential to map these vegetation classes because aerial photos have a higher spatial resolution than the satellite data. Small patches of herb slopes were selectively pinpointed in the photo-based mapping process. As the dominant vegetation types were, however, plotted in less detail, the photo-based mapping generally produced larger vegetation units with a more homogeneous and less complex texture than the satellite-based method.Of the two methods, the satellite-based method was by far the more cost-effective. Satellite data were less expensive to obtain and process than aerial photos and time-consuming interpretation was eliminated. Both methods require detailed ground-truthing, but the satellite-based method requires less so due to the objective classification procedure. Overall, the satellite-based method seems advantageous for vegetation mapping in large remote areas. However, the satellite data still lacks the resolution to map all the important cover classes of the fine-scaled arctic tundra vegetation mosaic. Therefore purpose-specific adaptation of cover classes and manual augmentation may be necessary.

Notes: Evaporation-elevation relationships for many areas of the tropics and subtropics are reviewed in an attempt to define general relationships and are discussed with respect to atmospheric profiles of temperature and humidity. At least three characteristic profiles can be identified: (i) a general decline in evaporation with elevation for most mountainous areas, (ii) a decrease in evaporation with elevation to a minimum (near 1,200 m in Hawai'i) and then a continual increase above that level for trade wind islands and possibly the subtropical Andes, and (iii) an increase in evaporation with elevation in a shallow layer (750 m in southern California) near sea level and a continual decrease above that level for dry, coastal, subtropical west coasts.

Notes: The Kaonde inhabit the savanna woodland plateaus of the Northwestern Province of Zambia. Primarily subsistence farmers, they have developed an agricultural system that consists of a chitemene form of long fallow cultivation and various forms of continuous cultivation. The different cultivation systems involve the exploitation of different environmental locations, where they are characterised by different agricultural practices and crop assemblages. Spatial variations in agricultural land use reflect locally varying environmental conditions. Given the prevalence of the tsetse fly, the Kaonde do not raise livestock, but over the last two decades some Kaonde farmers have engaged in fish-farming as a dietary supplement and cash crop.The Northwestern Province is the least populated, least developed, and most rural province in Zambia, yet recent population growth, notably in the close-settled zone around Solwezi Township (the provincial capital), has led to changes in the Kaonde agriculture system. Population pressure has led to the shortening of the fallows associated with long fallow cultivation, and an increased emphasis on existing forms of continuous cultivation. In a modified fashion, changes in Kaonde agricultural practices support the main contention of the Boserup theory that increases in population lead to the intensification of agriculture.

Notes: International commodity trading forms one of the three main activities attracted to international financial centres. A profile of international commodity exchange in Singapore is presented based partly on a survey of international traders approved under two government incentives (the approved international trader and approved oil trader schemes). The types of trading organisation, their activity, location decisions and evaluation of Singapore as a trading centre are discussed. Three office types are identified — the staging post, the regional mandate and the risk balancer. The regional mandate is the dominant model and is one aspect of a high level of regional containment to commodity trading. This finding is contrasted with the expectations of world city theory and its emphasis on the integration of financial centre activities into global markets.

Notes: The Pacific Islands present a different context for the study of human geography in the Third World. Though marked by much diversity in terms of culture, environment and history, there are key features which distinguish the region. Compared to elsewhere and with the notable exception of Papua New Guinea, they are small in terms of population, land area and resource base, yet many have attained independent nationhood. Island states are frequently fragmented so that small islands with small populations may be spread over vast expanses of ocean, creating particular problems of communication and integration. Moreover, the region is isolated. Although major trade routes cut across the Pacific, in practice, local economies are not well linked and outlying islands face high transport costs and infrequent services. Such features, largely peculiar to the Pacific, together with more universal themes of economic, cultural, political and social transformation have occupied the attention of human geographers in the past 40 years. Most early work was done by researchers from Australia, New Zealand and France but in the past two decades, the growth of regional tertiary institutions has led to a major growth of more locally-based work, much by Pacific Islanders themselves. Such a change has mirrored some major paradigmatic shifts, particularly from modernization theory through neo-Marxism to present interests in development from below and sustainability. Thus, despite the relative smallness of Pacific Island states, they have attracted much attention, both contributing to wider debates and adding new issues and perspectives on the processes of transformation of the geography of the Third World.

Notes: This overview of human geographic studies of sub Saharan Africa begins with the contributions made by West European geographers to the colonial service, and the growing interest in post-war ‘development’ and to the anti-imperial movements in the late colonial period (1945–60). The paper provides an intellectual map of the contributions by European and African geographers to the broad array of development problems which emerged after 1960. North American geographers made significant contributions to the debate somewhat later, particularly in association with the growing involvement of U.S. development agencies in the 1970s. Particular emphasis is given to geographic studies in fields such as agrarian change, ecological degradation, industrialization, human mobility and patterns of urbanization and settlement.

Notes: This paper reviews the directional shifts in human geographical research on Southeast Asia from 1945 to the present. It first begins with an overview of the identity of the region as conceived in various cultural traditions, such as the Greek, Arabic and Indian traditions. This is followed by an evaluation of regional geographies of Southeast Asia in the post-war period, highlighting the pre-eminence of the geostrategic definition of the region and the failure to come to grips with its rich cultural-historical identity. The paper then goes on to show that, arising from the changes in conceptual developments and methodologies in geography, the early regional emphasis then shifted to systematic concerns, with a movement away from ‘encyclopaedic’ to ‘adjectival’ geography (economic, urban, population, political, cultural and historical) and a greater emphasis on issues concerning national development. Since the 1980s, there have also been fewer regional works on Southeast Asia and though there are now many more indigenous geographers within the region, much of their research is based on their own national or provincial areas. However, this may shift again, given that rapid economic growth has now given the region prominence. Certainly, there is renewed multi-disciplinary interest in Southeast Asia.

Notes: Up to June 1993, 207 articles on physical geography have been published in the Malayan Journal of Tropical Geography (MJTG) (1953–57), Journal of Tropical Geography (JTG) (1958–79) and the Singapore Journal of Tropical Geography (SJTG) (1980–93). These articles are examined initially in terms of their sub-fields (Biogeography, Climatology, Geomorphology, Hydrology, and Soils), area of focus (the tropics, Africa, America, East Asia, South Asia, Southeast Asia excluding Malaysia and Singapore, Malaysia, Singapore, and Southwest Pacific) and the area of origin of the authors. The more significant papers in the sub-fields are indicated. Various factors influencing the contributions to the Journal and some insights on the contributions of local staff (Singapore and Malaysia) are also given. The significance of the Journal as an avenue for local and foreign authors and for papers on physical geography in the tropics is briefly evaluated.

Notes: Book reviwed in this articleSAR GEOCODING: DATA AND SYSTEMS. Edited by G. Schreier.INTRODUCTION TO ENVIRONMENTAL REMOTE SENSING. Third edition. By E. C. Barrett and L. F. Curtis.EUROPEAN SPACE DIRECTORY 1993. Eighth edition. Endorsed by Eurospace. Edited by D. Shirvanian.GEOMETRY, RELATIVITY, GEODESY. By H. Moritz and B. Hofmann-Wellenhof.TRATTATO DI FOTOGRAMMETRIA URBANA E ARCHITETTONICA. By M. Fondelli.LE RELEVE ET LA REPRESENTATION DE ĽARCHITECTURE. By J.-P. Saint Aubin.MEASUREMENT AND RECORDING OF HISTORIC BUILDINGS. By P. Swallow, D. Watt and R. Ashton.RELEVES PHOTOGRAMMETRIQUES DU PATRIMOINE EN REGIONS SISMIQUES. By M. Carbonnell.MAP GENERALIZATION: MAKING RULES FOR KNOWLEDGE REPRESENTATION. Edited by B. P. Buttenfield and R. B. McMaster.COMPILATION OF CARTOGRAPHIC AND SPACEBORNE REMOTE SENSING DATA FOR THEMATIC/TOPOGRAPHIC MAPPING. By U. Frei.PRACTICAL SURVEYING AND COMPUTATIONS. Second edition. By A. L. Allan.IMAGE PROCESSING, ANALYSIS AND MACHINE VISION. By M. Sonka, V. Hlavac and R. Boyle.SATELLITE GEODESY: FOUNDATIONS, METHODS, AND APPLICATIONS. By G. Seeber.VIDEOMETRICS. Edited by S. F. El-Hakim.GEOMETRIC AND RADIOMETRIC ANALYSIS OF A CCD-CAMERA BASED PHOTOGRAMMETRIC CLOSE-RANGE SYSTEM. By H. A. Beyer.AUSTRALIA ON PAPER: THE STORY OF AUSTRALIAN MAPPING. By J. D. Lines.VISUALIZATION IN BIOMEDICAL MICROSCOPIES: 3-D IMAGING AND COMPUTER APPLICATIONS. Edited by A. Kriete.INTEGRATING PHOTOGRAMMETRIC TECHNIQUES WITH SCENE ANALYSIS AND MACHINE VISION. Edited by E. B. Barrett and D. M. McKeown.STATE-OF-THE-ART MAPPING. Edited by B. P. Clark, A. Douglas, B. L. Foley, B. Huberty and L. D. Whitmill.STEREOSCOPIC DISPLAYS AND APPLICATIONS IV. Edited by J. O. Merritt and S. S. Fisher.PROCEEDINGS OF THE OEEPE WORKSHOP ON DATA QUALITY IN LAND INFORMATION SYSTEMS, APELDOORN, NETHERLANDS, 4-6 SEPTEMBER 1991. Edited by L. A. Koen and O. Kölbl.CONTOURING: A GUIDE TO THE ANALYSIS AND DISPLAY OF SPATIAL DATA. By D. F. Watson.

Notes: Photogrammetrists are acutely aware that remote methods of survey are commonplace. However, it is only relatively recently that high precision levelling of the national motorway network has been conducted in this manner. There are now several competing methods available, all of which have gained some acceptance. This paper describes a low level aerial photographic method employing a helicopter as the platform. It begins with the reasons for the development, describes the system and methods involved, addresses the safety aspects, attempts to outline the necessity for the largest scale possible to maintain precision, analyses the potential developments and discusses the advantages and disadvantages compared with ground based systems.

Notes: This paper discusses analytical relative orientation for two-media photogrammetry. After a brief introduction concerning the collinearity condition, the coplanarity equation is derived, which is similar inform to the conventional expression. By considering the differences from one-medium photogrammetry, the computational strategy of relative orientation for two-media photogrammetry is studied, including linearization of the equation, the correction for refraction and, especially, the determination of the boundary between the two media. Simulated test results verify the theoretical analysis. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On étudie dans cet article ľ orientation relative analytique dans la photogrammétrie à deux milieux. Après une brève introduction relative à la condition de colinéarité, on en dérive les équations de coplanarité dont la forme est tout à fait semblable à celle du cas classique. On dégage ensuite une stratégie de calcul de ľ orientation relative pour la photogrammétrie à deux milieux, en s'attachant aux différences avec celle à un seul milieu, et en mentionnant la linéarisation des équations, la correction de la réfraction et, plus particulièrement, la détermination de la limite entre les deux milieux. Les résultats obtenus sur des simulations sont conformes àľ‘analyse théorique. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung ImArtikelwirddie analytische relative Orientierung für die Zweimedien-Photogrammetrie diskutiert. Nach einer kurzen Einführung, die sich mit der Kollinearitätsbedingung befaβt, weden Komplanaritätsgleichungen ähnlich der konventionellen Form abgeleitet. Unter Beachtung der Unterschiede zur Einmedium-Photogrammetrie wird die rechnerische Strategic der relativen Orientierung für die Zweimedien-Photogrammetrie studiert. Das schließt die Linearisierung der Gleichungen, die Refraktionskorrektur und besonders die Bestimmung der Grenze zwischen den beiden Medien ein. Simulierte Testergebnisse bestdtigen die theoretische Analyse.

Notes: Book Reviewed in this article:THE MICROSCOPIC PHOTOGRAPHS OF J. B. DANCER. By B. Bracegirdle and J. B. McCormick.ROBOT CALIBRATION. Edited by R. Bernhardt and S. L. Albright.BASIC CARTOGRAPHY FOR STUDENTS AND TECHNICIANS: VOLUME 1. Second edition. Edited by R. W. Anson and F. J. Ormeling.A HALF AND HALF AFFAIR: CHRONICLES OF A HYBRID DON. By D. R. Denman.IMAGE INTERPRETATION IN GEOLOGY. Second edition. By S. A. Drury.VERMESSUNG UND ORTUNG MIT SATELLITES NAVSTAR-GPS UND ANDERE SATELLITENGESTUTZTE NAVIGATIONSSYSTEME. Second edition. By M. Bauer.HANDBOOK OF THE MOIRE FRINGE TECHNIQUE. By K. Patorski.LANDSCAPE ECOLOGY AND GEOGRAPHIC INFORMATION SYSTEMS. Edited by R. Haines-Young, D. R. Green and S. H. Cousins.INTRODUCTION TO INTEGRATED GEO-INFORMATION MANAGEMENT. By S. Cassettari.GEOGRAPHIC INFORMATION 1994: THE SOURCE BOOK FOR GIS. Edited by D. R. Green, D. Rix and J. Cadoux-Hudson.CAMERAS, SCANNERS, AND IMAGE ACQUISITION SYSTEMS. Edited by H. C. Marz and R. L. Nielsen.INVENTORY OF WORLD TOPOGRAPHIC MAPPING. Volume 3, Eastern Europe, ASIA, Oceania and Antarctica. Compiled by R. Böhme. English language editor R. Anson.POSTPROCESSING VON SAR-SATELLITENBILDDATEN. By F. Holecz.DISPLAY SYSTEMS. Edited by C. T. Bartlett and M. D. Cowan.STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS. Edited by S. S. Fisher, J. O. Merritt and M. T. Bolas.

Notes: Photographic lenses are produced in a variety of types for numerous image formats. Innovations in optical technology enable technically advanced lenses to be produced and camera systems improved. Following descriptions of computer aided design and manufacture and the importance of new optical materials, aspheric surfaces and floating elements, several types of lenses are described in detail, including zoom, soft focus, high resolution, micro, large format and telephoto designs. Also discussed are optical attachments and the optical systems of compact cameras, viewfinders and three-chip video cameras.

Notes: Treaty verification involves the acquisition and interpretation of data to establish a country's compliance to an agreement. Remote sensing and photogrammetry in verification is established in the intelligence community and is progressively entering the civilian sector as well. The Open Skies Treaty and the proliferation of commercial satellite imagery have created a niche for open, multilateral verification. These recent developments come at an opportune moment as the verification task has become more cumbersome and complex.This paper surveys the changes in the field of verification, aerial monitoring and satellite surveillance. It details existing and future verification tasks and presents the operational capabilities for fulfilling those tasks. The limiting factors are also presented.

Notes: In a continuing drive to reduce the radiation exposure of nuclear workers, many routine aspects of nuclear plant maintenance and refurbishment are increasingly undertaken by robotic or remote handling tools. Accurate “as built” documentation of plant records is vital to the successful planning and execution of such operations since an unexpected obstruction or undocumented site modification may result in a costly disruption or even failure of the intervention. In recognition of the importance of such documentation, a recent European Community† sponsored project has been directed towards the development of techniques for cost effective survey and modelling of such plant. This paper will detail the rationale behind the design of such a system and will describe typical results from a number of pilot projects.

Notes: Some of the economic and operational aspects of mapping are discussed, including the conditions that may offer air survey a competitive advantage over other methods. The financing of national mapping programmes around the world is increasingly market oriented, driven by the need to provide the end users with information that they can turn into sustainable economic growth and social progress. Despite these economic pressures, map makers seem to find their work more enjoyable and rewarding than most professionals.

Notes: The paper entitled The Photogrammetric Society Analogue Instrument Project was published in The Photogrammetric Record, 14(82): 565-582 (October 1993). It contained, as Appendix A, the entry from the Archive that dealt with the Zeiss Stereoplanigraph. This paper provides a second extract from the Archive concerned with the entries relating to the Barr & Stroud ZA1 plotter, the Williamson Multiplex equipment and the Thompson pinhole plotter.

Notes: A case is made for the development of an inexpensive and portable data capturing unit which could be used with existing mirror stereoscopes and which could provide an accuracy sufficient for most digital map databases. The results of simulation experiments to test the accuracy of the system are presented.

Notes: The pianoforte in the Mozarthaus at Salzburg is a state of the art instrument of the late 18th century. It was recorded photogrammetrically in order to enable fundamental musicological investigations to be carried out. An important aspect of the piano survey was high precision three dimensional point determination performed by combined bundle adjustment. The process was optimized by use of software tools for simulation, automatic error detection and graphical analysis of the adjustment results. This procedure considerably increased the efficiency and reliability of the photogrammetric reconstruction.

Notes: Although accuracy of digital elevation models (DEMs) can be quantified and measured in different ways, each is influenced by three main factors: terrain character, sampling strategy and interpolation method. These parameters, and their interaction, are discussed. The generation of DEMs from digitised contours is emphasised because this is the major source of DEMs, particularly within member countries of OEEPE. Such DEMs often exhibit unwelcome artifacts, depending on the interpolation method employed. The origin and magnitude of these effects and how they can be reduced to improve the accuracy of the DEMs are also discussed.

Notes: Book Reviewed in this article: Joe Doherty, Elspeth Graham and Mo Malek (eds.) Postmodernism and the Social Sciences. Paul Cloke (ed.) Policy and Change in Thatcher's Britain. Ludwik Mazurkiewicz Human Geography in Eastern Europe and the Former Soviet Union. J. W. R. Whitehand and P. J. Larkham (eds.) Urban Landscapes: International Perspectives. Bernard Woods. Communication, Technology and the Development of People.

Notes: A number of geographers have recently championed the struggle against Eurocentric theoretical categorizations in geographical research on African cities. At the same time, many whose work has concentrated on African urban geography have felt left out in the more abstract theoretical debates of their colleagues based in the West. I argue for the possibility of confronting Western bias and contributing to broader theoretical debates by creating theoretical constructs derived from the African experience. I develop my argument through an analysis of urban development in Ng'ambo, the African “Other Side” of Zanzibar city, and work toward the creation of meso-level conceptual guides for understanding Ng'ambo's development derived from the ideas of Ng'ambo residents themselves.