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: Hydrogen gas was discovered within the steel casing above standing water in a percussion-drilled borehole on the Hanlord Site in south-central Washington state. In situ measurements of the borehole fluids indicated anoxic, low-Eh (〈-400 mV) conditions. Ground water sampled from adjacent wells in the same formation indicated that the ground water was oxygenated. H2 was generated during percussion drilling, due to the decomposition of borehole waters as a result of aqueous reactions with drilled sediment and steel from the drilling tools or casing. The generation of H2 within percussion-drilled boreholes that extend below the water table may be more common than previously realized. The ambient concentration of H2 produced during drilling was limited by microbial activity within the casing-resident fluids. H2 was generated abiotically in the laboratory, whereby sterilized borehole slurry samples produced 100 times more H2 than unsterilizcd samples. It appears that H2 is metabolized by microorganisms and concentrations might be significantly greater if not for microbial metabolism.

Notes: Measurement accuracy was increased by nearly one order of magnitude by outfitting the thermal-pulse flowmeter (TFM) with an inflatable packer. To accurately measure slow water velocities in boreholes greater than 15 cm diameter, it is necessary to divert borehole fluids through the TFM by inflating a packer. During calibration it was noted that the TFM's accuracy decreased as the borehole diameter increased. With Lhe packer inflated the TFM has a useful flow measurement range of 0.08 to 15 L/min (with flow velocities of 0.24 ± 0.012 cm/inin to 45.7 ± 0.61 cm/min, respectively, in 20-cm-diameter pipe), compared to 0.8 to 57 L/min for a packcrless TFM. A computer interlace was added to the TFM to provide a real-time graphical display of the differential voltage output from the TFM, a running mean and standard deviation of the pulse-response time, and a mean flow rate and velocity based on calibration curve fits.

Notes: The Nguyen and Pinder method is one of four techniques commonly used for analysis of response data from slug tests. Limited field research has raised questions about the reliability of the parameter estimates obtained with this method. A theoretical evaluation of this technique reveals that errors were made in the derivation of the analytical solution upon which the technique is based. Simulation and field examples show that the errors result in parameter estimates that can differ from actual values by orders of magnitude. These findings indicate that the Nguyen and Pinder method should no longer be a tool in the repertoire of the field hydrogeologist. If data from a slug test performed in a partially penetrating well in a confined aquifer need to be analyzed, recent work has shown that the Hvorslev method is the best alternative among the commonly used techniques.

Notes: Nonparametric prediction limits can be useful statistical tools for ground water monitoring at facilities regulated under RCRA Subtitle C. Subtitle D. and similar regulations. New, exact tables arc presented for both “1 of m” plans (m chances to gel one observation inbounds at each of r monitoring wells to avoid a statistically significant increase) and “California” plans (first or all of the next m-1 observations inbounds at each well). The tables provide per-constituent significance levels (false positive rates) as a function of the background sample size n. m. r, the prediction limit (the largest or the next to largest, background observation), and the confirmatory resampling plan selected.When used in a monitoring program, future observations from several wells are compared with a prediction limit obtained from a common background sample. The table significance levels therefore depend critically on having IID (independent and identically distributed) observations. In particular, the false positive rate computations are not valid, and the procedures should not be used, with constituents whose measurements exhibit inherent spatial or systematic temporal variability.Recent U.S. EPA guidance explicitly encourages controlling facility-wide false positive rates over both constituents and wells. Nonparametric prediction limits, particularly with California resampling plans, will have greater difficulty in meeting the new. lower per-constituent false positive rate goals than previous ones, especially if many constituents are involved. Nonetheless, nonparametric prediction limits remain superior to other commonly used procedures for dealing with data with high proportions of nondctects.

Notes: On-site analysis of trichloroethylene (TCE) in aqueous samples by head- space sample preparation and gas chromatography (HS/GC) provides for quick and precise concentration estimates. This analytical approach is well suited for the on-site determination of volatile organic compounds (VOCs) in a variety of sample matrices, including ground water and saturated and unsatured soils. For these reasons, HS/GC can be used to establish analyte concentrations on a near real time basis to help select appropriate casing material during monitoring well installation. This application and the collection of multiple well samples during sampling events facilitates the hydrogeological site interpretation and the formulation of remediation strategies.

Notes: The vertical distribution and partitioning (between the solid and aqueous phase) of chromium in a glaciofluvial aquifer in northeastern Connecticut were assessed. Most of the chromium (99 percent of its mass) is bound to the soil. Retardation is primarily the result of binding to organic matter and adsorption to iron oxide coatings. However, other attenuation mechanisms also appear to be significant. If the degree of chromium binding observed here is representative of other chromium contaminated sites, pump-and-treat remediation will not remove the vast amount of chromium from the subsurface. However, most of the chromium may be immobile, and removal may not be required following the initial pumping to remove the mobile fraction. Further knowledge of the mechanisms that bind chromium to the soil, their reversibility, and their kinetics is essential to developing effective remediation strategies.

Notes: Surfactant solutions are being proposed for in situ flushing of organic contaminants from soils and aquifers. The feasibility of surfactant additives in remediation may depend in large part on how these chemicals affect the hydraulic conductivity of the porous media. While there is evidence in the literature of conductivity loss during surfactant flushing (Miller et al. 1975; Nash et al. 1987), there has been little research on quantifying the process for unconsolidated sediments. Surfactant-affected hydraulic conductivity reductions were measured in two soils (Teller loam and Daugherty sand). Testing was done with eight surfactants at a variety of concentrations (10-5 to 10-l mole/kg), surfactant mixtures, and added solution electrolytes. The Teller was also tested with its organic matter removed. Maximum hydraulic conductivity decreases were 47 percent for the sand and more than two orders of magnitude for the loam. Surfactant concentrations, surfactant mixtures, soil organic content, and added solution electrolytes all affected the degree of conductivity reduction. Results indicate that surfactant-affected hydraulic conductivity losses should be considered prior to in situ remediation and may preclude surfactant use in some fine grain soils.

Notes: Soil gas samples from intact soil cores were collected on adsorbents at a field site, then thermally desorbed and analyzed by laboratory gas chromatography (GC). Vertical concentration profiles of predominant vapor phase petroleum hydrocarbons under ambient conditions were obtained for the zone directly above the capillary fringe. Water and residual phase weathered aviation gasoline were present in this region of the profile.The sampling, trapping, and GC methodology was effective in most respects. Reproducibility, trapping, and desorption efficiency were generally satisfactory, and different sorbent tubes gave similar results. A minor shortcoming of the method occurred with the most volatile compound, 2,3-dimcthylbutane, which was poorly retained during several weeks of storage lime and was also poorly desorbed.Vapor phase concentrations of predominant hydrocarbon compounds all increased with depth at one sampling location. At a more highly contaminated location, concentrations of highly volatile compounds increased with depth while concentrations of less volatile compounds remained constant or decreased, possibly indicating distillation effects. Scatier in the data was attributed to heterogeneities in water and residual phase distribution.

Notes: The Sankey Brook catchment lies in the heart of the Mersey basin. As part of a major study into development issues in the Sankey Brook catchment, a hydraulic model was constructed and successfully used to simulate the river system and to assist in the derivation of discharge control policies.The background to the study and the subsequent hydrological and hydraulic modelling are described, particularly in relation to the more complex systems in the lower reaches of Sankey Brook.

Notes: Osaka has nearly completed its sewerage system, and twelve sewage-treatment works are now in operation. Tsumori and Ebie works, the two oldest, were commissioned in 1940. For these works, full-scale reconstruction has just commenced.This paper reports on the reconstruction of the Tsumori works, and outlines the plan for future reconstruction of the city's sewage-treatment works.

Notes: The paper outlines how consent standards are normally calculated in Scotland for both river systems and tidal waters. A background is given to the reason why a more statistical approach has been adopted in England and Wales where the use of combining distribution methods is more widespread. Comparison of the two approaches is made, particularly with regard to their potential impact on resources required for treatment plants, and also the problems of taking enforcement action. The setting of standards under the EC urban waste water treatment Directive is considered where, in addition to the implications of primary, secondary and more stringent treatment, consideration is given to storm-sewage overflows and industrial discharges.

Notes: The introduction of ultraviolet disinfection in Jersey has achieved significant improvements in water quality. However, bathing waters in St Aubin's Bay and shellfish flesh have failed to comply with microbial standards. Streams and seepages from coastal structures were investigated as potential indicator organism sources (total and faecal coliforms, faecal streptococci). Seepages were an unimportant bacterial source as concentrations were low. Geometric mean concentrations in streams were up to four orders of magnitude higher than in final sewage-treatment works effluent, and concentrations increased significantly at high stream discharge. Rainfall-induced pulses of poor water quality occurred two to three times per week during the 1993 summer season. Natural discharges from island catchments thus contribute significantly to the bacterial load received at the coast, especially during high flow events. These observations have implications for other UK and European schemes using tertiary disinfection technology to attain water quality targets in coastal waters.

Notes: British Gas owns over 900 sites within the UK with a total land area in excess of 5500 ha. Many of the sites are former gasworks, chemical works or associated holder stations.Although serious attempts were made to remove contamination during the last three decades, the operating and demolition standards previously considered to be adequate may no longer be acceptable and may have given rise to sites with the potential to contaminate adjacent land, surface waters and ground-water. As a result, further actions may now be required on these sites to reach new environmental standards, thereby reducing any chance there may be of legal liability on the Company.This paper describes the advantages and disadvantages of several qualitative and quantitative risk-assessment methods which can be used to prioritize potentially contaminated sites for further investigation. The use of site investigation data to accurately target risk reduction in site remediation proposals is also discussed.

Notes: Using regional statistics of daily rainfall, a simple water-balance model was employed to generate runoff sequences with which to simulate the yield/storage behaviour of reservoirs in south-east England, in north-west England, and North Wales. Similarly sequences of recharge to an unconfined aquifer in eastern England were the basis of deriving its yield/storage behaviour. Then, taking scenarios of the year 2030 rainfall and evaporation, provided by the University of East Anglia's Climatic Research Unit, reductions in yield were calculated to be 5–15% below present-day values. For direct supply reservoirs, greater percentage reductions in yield were found to apply to the south-east region, as compared to the north-west. The results from the aquifer example are interpreted on a novel basis which allows an immediate comparison with the surface reservoir examples.Coastal sea-water intrusion was modelled for three common geological conditions (i) the Grimsby Chalk (confined), (ii) the Brighton Chalk (unconfined), and (hi) the Otter Valley Sandstone (unconfined). In all three cases the effect of a possible 0.6 m rise in mean sea level was shown to have only a marginal effect on sustainable yields, which reduced by about 1.5%.Estuarine fresh-salt water interfaces are important to the abstraction regime of freshwater intakes in the lower reaches of rivers. The effect of a 0.6-m sea-level rise on the saline interface location at high tide was evaluated by hydrodynamic computational models. Only a minor inland shin of the interface was found, less man 800 m in the Thames tideway and less than 500 m in the Lune estuary. The Severn estuary is exceptional in having its saline interface move 3.5 km landwards for the same 0.6-m rise in mean sea level.

Notes: During the long-distance pressure transportation of sewage, the interior of a rising main tends to become anaerobic, thereby producing a large amount of hydrogen sulphide at manholes and terminals. High concentrations of hydrogen sulphide have become a serious environmental and maintenance problem.In order to prevent the production of hydrogen sulphide in rising mains, the City of Kobe (in Japan) introduced a system to inject air directly into the main.This paper describes the results of studies on the effect of air injection on hydrogen sulphide inhibition and the relationship between water quality and the amount of air injected.

Notes: This paper describes the experience gained by Yorkshire Water in the construction and operation of a wastewater treatment plant to deal with the effluent from Europe's largest canning and bottling factory (at Wakefield, West Yorkshire). The process which was chosen was the ‘Biothane’ upward-flow anaerobic sludge blanket system. Commissioning of the plant was fraught with difficulties due to the erratic organic load being discharged from the factory, along with larger than anticipated volumes of caustic solution.

Notes: The problems of water-colour management in peatland catchments are discussed. Colour may be managed in three areas of the reservoir catchment system: on the catchment itself, in the channel/conduit system and within the reservoir. Whilst a number of workers have considered the management of catchment areas and some have evolved tributary turnout strategies, no previous research has considered the role of the reservoir in the amelioration or enhancement of water colour. The management of water colour at Thornton Moor catchment (near Bradford) is described. In this catchment a staged approach has been adopted, with colour being managed in an integrated manner at three stages along the catchment/conduit/reservoir system.

Notes: Books reviewed in this article: Water Wisdom, by Colin Allsebrook. Regional Ground-Water Quality. Edited by W. M. Alley. Respirometry of Activated Sludge, by Milenko Ros. Strategy for the Sustainable Use of England's Estuaries, by English Nature. European Environmental Law Casebook, by L. Krämer.

Notes: Stream gauging data play a vital role in the planning of flood mitigation strategies. A study of the value of stream flow data for the design of levee systems shows that the availability of a reasonable sample of pertinent data can be worth many times the cost of collecting that data.

Notes: In 1985 the House of Commons Environment Committee expressed reservations over some of the waste-management procedures followed by British Nuclear Fuels Ltd at their Drigg low-level radioactive waste disposal facility near Sellafield in Cumbria. These reservations prompted the company to implement a £20 million programme of improvements aimed at maximizing site usage, reducing trench leachate arisings and redirecting to the Irish Sea.This paper provides information and test results associated with design considerations and initial dilution testing, respectively, of a computercontrolled long sea outfall system designed to discharge leachate to the Irish Sea. Information is also provided on difficulties experienced during construction of the outfall.

Notes: Since 1987 British Gas plc has undertaken an extensive programme of medium pressure (up to 2 bar) cast-iron mains replacement in urban locations, using a variety of rehabilitation techniques.This paper describes the experience of North Thames Region of British Gas plc, over the period 1987–1991, when the rehabilitation of over 230 km of mains was undertaken in the size range 300–460 mm.The techniques which were used favoured medium density polyethylene pipe wherever possible. However, about 100 km of rehabilitation was undertaken using hoselining, usually where mains were larger than 460 mm dia., or where aboveground access was restricted, or if the mains configuration included many changes of direction.This paper deals with (a) various aspects of operating rehabilitation contracts from a public utilities viewpoint, (b) the special factors relating to the inspection and testing of hoselined mains including factors found to contribute to failure, and (c) some of the controls that have been introduced to improve reliability of rehabilitation systems.

Notes: The use of cement kilns for managing solid and hazardous wastes is facilitated by the high temperature, long gas retention periods, natural alkaline environment, minimum amount of waste produced and high thermal capacity. The main benefits include energy recovery, conservation of fossil fuels, reduction in cement production costs and the use of already existing facilities.The test burns conducted in cement kilns worldwide have demonstrated very high destruction efficiencies for most stable organic compounds, with toxic contaminants barely above the background levels.There are several cement plants in the US and Europe presently using solid and hazardous wastes as supplementary fuel. The application of this technology in Australia has been ignored in the past. An international conference (Kilnburn‘92) on the role of cement kilns in waste management was held recently in Australia and has enhanced the implementation of this technology in Australia.

Notes: The capacity of the sewage-treatment works at Silchester in Hampshire has been enhanced and the effluent quality improved to a high standard by the installation of a new submerged biological aerated filter plant. Ten prefabricated steel submerged aerated filters reduce BOD and fully nitrify settled domestic sewage from a population equivalent of 20 000.Comprehensive operating data are presented to demonstrate the ability of single-stage submerged downflow aerated biological filters to produce a nitrified effluent. The final effluent quality remains consistently within consent limits at 4.8 mg/l BOD, 7.0 mg/l SS and 0.5 mg/l NH3-N, all 95 percentiles. (Consent 7 mg/l BOD, 25 mg/l SS, and 5 mg/l NH3-N, 95 percentiles.)Data are presented on total coliform and E. Coli concentrations through the filter plant, showing better than 3 log reductions in the effluent.

Notes: In recent years an increase in the eutrophication of reservoirs has added to the problems of lowland surface-water treatment. A pilot plant was installed to test the effectiveness of various treatment regimes for a river source which was subject to occasional algal blooms, and a eutrophic reservoir source which was heavily contaminated with cyanobacteria (Oscillatoria sp.). The treatment processes adopted were dissolved-air flotation for chemical coagulation, sand and anthracite filtration, comparative disinfection stages using ozone and chlorine followed by granular activated carbon filtration.The dissolved-air flotation plant was not particularly effective for the removal of algae, but the sand/anthracite filtration process was capable of removing 50% of the algae. The ozone disinfection stage was adequate for disinfection and also reduced algal numbers. Overall the chlorine/granular activated carbon method did not perform as effectively as the ozone/granular activated carbon process; the iatter process was +99% effective for algai control, with river and reservoir sources.

Notes: An intermittent strong vegetable/cabbage odour was noted on raw water abstracted from the River Dee (NW England). The source of the odour was traced to an industrial discharge from an animal feed manufacturer to a tributary of the River Dee. Analysis of water samples by CLSA GC-MS revealed the likely causes of the odour to be dimethyl disulphide and dimethyl trisulphide. 2-hydroxy-4-(methylthio)butanoic acid (HMB), a hydroxy methionine analogue growth supplement used by the feed manufacturer was a likely precursor to the odour problem. Studies conducted on the behaviour of HMB in untreated water showed it to be rapidly degraded. Degradation products included dimethyl disulphide, dimethyl trisulphide and methyl(methylthio)methyl disulphide. The odour of water samples incubated with HMB changed from that of potato to cabbage/sprout, indicating that breakdown of this compound was responsible for the vegetable odour on untreated river water.

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: The paper by Metz challenges the view that stigma associated with a nuclear waste repository might lead to significant economic losses to the host region. We have been invited to comment on the general issues raised by this paper. We find that much of the evidence presented in the paper consists of factual and conceptual errors and misrepresentations of the research literature. Based on our review of evidence documenting the social and economic impacts of perceived risk, we conclude that stigma is an important phenomenon that is symptomatic of fundamental problems with the way in which nuclear waste facilities are sited.

Notes: Many risk communications are intended to help the lay public make complex decisions about risk. To guide risk communicators with this objective, a mental models approach to the design and characterization of risk communications is proposed. Building on text comprehension and mental models research, this approach offers an integrated set of methods to help the risk communication designer choose and analyze risk communication content, structure, and organization. An applied example shows that two radon brochures designed with this approach present roughly the same expert facts as a radon brochure widely distributed by the U.S. EPA but meet higher standards on other content, structure, and organization criteria.

Notes: It has recently been suggested that “standard” data distributions for key exposure variables should be developed wherever appropriate for use in probabilistic or “Monte Carlo” exposure analyses. Soil-on-skin adherence estimates represent an ideal candidate for development of a standard data distribution: There are several readily available studies which offer a consistent pattern of reported results, and more importantly, soil adherence to skin is likely to vary little from site-to-site. In this paper, we thoroughly review each of the published soil adherence studies with respect to study design, sampling, and analytical methods, and level of confidence in the reported results. Based on these studies, probability density functions (PDF) of soil adherence values were examined for different age groups and different sampling techniques. The soil adherence PDF developed from adult data was found to resemble closely the soil adherence PDF based on child data in terms of both central tendency (mean = 0.49 and 0.63 mg-soil/cm2-skin, respectively) and 95th percentile values (1.6 and 2.4 mg-soil/cm2-skin, respectively). Accordingly, a single, “standard” PDF is presented based on all data collected for all age groups. This standard PDF is lognormally distributed; the arithmetic mean and standard deviation are 0.52 ± 0.9 mg-soil/cm2-skin. Since our review of the literature indicates that soil adherence under environmental conditions will be minimally influenced by age, sex, soil type, or particle size, this PDF should be considered applicable to all settings. The 50th and 95th percentile values of the standard PDF (0.25 and 1.7 mg-soil/cm2-skin, respectively) are very similar to recent U.S. EPA estimates of “average” and “upper-bound” soil adherence (0.2 and 1.0 mg-soil/cm2-skin, respectively).

Notes: A Latin Hypercube probabilistic risk assessment methodology was employed in the assessment of health risks associated with exposures to contaminated sediment and biota in an estuary in the Tidewater region of Virginia. The primary contaminants were polychlorinated biphenyls (PCBs), polychlorinated terphenyls (PCTs), polynuclear aromatic hydrocarbons (PAHs), and metals released into the estuary from a storm sewer system. The exposure pathways associated with the highest contaminant intake and risks were dermal contact with contaminated sediment and ingestion of contaminated aquatic and terrestrial biota from the contaminated area. As expected, all of the output probability distributions of risk were highly skewed, and the ratios of the expected value (mean) to median risk estimates ranged from 1.4 to 14.8 for the various exposed populations. The 99th percentile risk estimates were as much as two orders of magnitude above the mean risk estimates. For the sediment exposure pathways, the stability of the median risk estimates was found to be much greater than the stability of the expected value risk estimates. The interrun variability in the median risk estimate was found to be +/-1.9% at 3000 iterations. The interrun stability of the mean risk estimates was found to be approximately equal to that of the 95th percentile estimates at any number of iterations. The variation in neither contaminant concentrations nor any other single input variable contributed disproportionately to the overall simulation variance. The inclusion or exclusion of spatial correlations among contaminant concentrations in the simulation model did not significantly effect either the magnitude or the variance of the simulation risk estimates for sediment exposures.

Notes: This report summarizes the proceedings of a conference on quantitative methods for assessing the risks of developmental toxicants. The conference was planned by a subcommittee of the National Research Council's Committee on Risk Assessment Methodology/〉 in conjunction with staff from several federal agencies, including the U.S. Environmental Protection Agency, U.S. Food and Drug Administration, U.S. Consumer Products Safety Commission, and Health and Welfare Canada. Issues discussed at the workshop included computerized techniques for hazard identification, use of human and animal data for defining risks in a clinical setting, relationships between end points in developmental toxicity testing, reference dose calculations for developmental toxicology, analysis of quantitative dose-response data, mechanisms of developmental toxicity, physiologically based pharmacokinetic models, and structure-activity relationships. Although a formal consensus was not sought, many participants favored the evolution of quantitative techniques for developmental toxicology risk assessment, including the replacement of lowest observed adverse effect levels (LOAELs) and no observed adverse effect levels (NOAELs) with the benchmark dose methodology.

Notes: The kinetics of disposition of drugs and environmental chemicals will be altered as a result of the rapid and pronounced anatomic and physiologic changes that occur during pregnancy. These include changes in maternal intestinal motility, pulmonary tidal volume and minute volume, cardiac output, and renal function as well as in maternal tissue and fluid volumes and in the weight of the embryo/fetus and its developing organs. Physiologically-based models of pregnancy are capable of taking these temporal changes into account. Several such models have been developed. They vary in their characteristics, depending on the chemical under consideration and the period of gestation of concern to the developers of the models. Several physiologically-based models of gestation are outlined, and an example is given of the application of a physiologically-based model of gestation to predict dose to the rat and mouse fetus.

Notes: Although public perceptions of food-related hazards receive much media comment and debate, the research literature on such perceptions is sparse and piecemeal. In the reported study, 216 people completed a questionnaire relating to their perceptions of the “risk characteristics” of potential hazards associated with various aspects of food production and food consumption. Responses were examined via principal-components analysis to obtain a structural representation of risk perception of the kind provided by Fischhoff, Slovic, and their colleagues in their seminal psychometric work.(1,2) A three-component solution accounting for 87% of the variance was obtained, with the dimensions labeled as “severity,”“unknown,” and “number of people exposed.” The findings also yielded information pointing to evidence of the phenomenon of unrealistic optimism. We conclude that our findings offer a useful base upon which further in-depth research integrating different perspectives on risk perception with respect to food-related hazards may be developed.

Notes: Concern about the degree of uncertainty and potential conservatism in deterministic point estimates of risk has prompted researchers to turn increasingly to probabilistic methods for risk assessment. With Monte Carlo simulation techniques, distributions of risk reflecting uncertainty and/or variability are generated as an alternative. In this paper the compounding of conservatism(1) between the level associated with point estimate inputs selected from probability distributions and the level associated with the deterministic value of risk calculated using these inputs is explored. Two measures of compounded conservatism are compared and contrasted. The first measure considered, F, is defined as the ratio of the risk value, Rd, calculated deterministically as a function of n inputs each at the jth percentile of its probability distribution, and the risk value, Rj that falls at the jth percentile of the simulated risk distribution (i.e., F=Rd/Rj). The percentile of the simulated risk distribution which corresponds to the deterministic value, Rd, serves as a second measure of compounded conservatism. Analytical results for simple products of lognormal distributions are presented. In addition, a numerical treatment of several complex cases is presented using five simulation analyses from the literature to illustrate. Overall, there are cases in which conservatism compounds dramatically for deterministic point estimates of risk constructed from upper percentiles of input parameters, as well as those for which the effect is less notable. The analytical and numerical techniques discussed are intended to help analysts explore the factors that influence the magnitude of compounding conservatism in specific cases.

Notes: For noncancer effects, the degree of human interindividual variability plays a central role in determining the risk that can be expected at low exposures. This discussion reviews available data on observations of interindividual variability in (a) breathing rates, based on observations in British coal miners; (b) systemic pharmacokinetic parameters, based on studies of a number of drugs; (c) susceptibility to neurological effects from fetal exposure to methyl mercury, based on observations of the incidence of effects in relation to hair mercury levels; and (d) chronic lung function changes in relation to long-term exposure to cigarette smoke. The quantitative ranges of predictions that follow from uncertainties in estimates of interindividual variability in susceptibility are illustrated.

Notes: Uncertainties are usually evaluated by Monte Carlo analysis. However, multiplicative models with lognormal uncertainties, which are ubiquitous in risk assessments, allow for a simple and quick analytical uncertainty analysis. The necessary formulae are given, which may be evaluated by a desk calculator. Two examples illustrate the method.

Notes: Although there has been nearly complete agreement in the scientific community that Monte Carlo techniques represent a significant improvement in the exposure assessment process, virtually all state and federal risk assessments still rely on the traditional point estimate approach. One of the rate-determining steps to a timely implementation of Monte Carlo techniques to regulatory decision making is the development of “standard” data distributions that are considered applicable to any setting. For many exposure variables, there is no need to wait any longer to adopt Monte Carlo techniques into regulatory policy since there is a wealth of data from which a robust distribution can be developed and ample evidence to indicate that the variable is not significantly influenced by site-specific conditions. In this paper, we propose several distributions that can be considered standard and customary for most settings. Age-specific distributions for soil ingestion rates, inhalation rates, body weights, skin surface area, tapwater and fish consumption, residential occupancy and occupational tenure, and soil-on-skin adherence were developed. For each distribution offered in this paper, we discuss the adequacy of the database, derivation of the distribution, and applicability of the distribution to various settings and conditions.

Notes: We propose a decision-analytic framework, called the mental models approach, for evaluating the impact of risk communications. It employs multiple evaluation methods, including think-aloud protocol analysis, problem solving, and a true-false test that allows respondents to express uncertainty about their answers. The approach is illustrated in empirical comparisons of three brochures about indoor radon.

Notes: Measurements of intermediate end points in the carcinogenic process may reduce uncertainty in human risk assessment from bioassay data, by identifying sources of interspecies variation and dose nonlinearity. This paper describes desirable properties of such markers: persistence, predictive power, temporal relevance, and consistency across dose rate and species. We illustrate these properties by evaluating markers for squamous cell nasal carcinoma in rodents exposed to formaldehyde. We also discuss design issues for bioassays that evaluate markers and tumors simultaneously at necropsy.

Notes: Potential health risks from exposure to power-frequency electromagnetic fields (EMF) have become an issue of significant public concern. This study evaluates a brochure designed to communicate EMF health risks from a scientific perspective. The study utilized a pretest-posttest design in which respondents judged various sources of EMF (and other) health and safety risks, both before reading the brochure and after. Respondents assessed risks on dimensions similar to those utilized in previous studies of risk perception. In addition, detailed ratings were made that probed respondents’ beliefs about the possible causal effects of EMF exposure. The findings suggest that naive beliefs about the potential of EMF exposure to cause harm were highly influenced by specific content elements of the brochure. The implications for using risk-communication approaches based on communicating scientific uncertainty are discussed.

Notes: Using the revised risk coefficients recommended by the 1990 report of the International Commission of Radiological Protection (ICRP), computations have been made on the minimum databases required for detecting radiogenic cancer excesses from epidemiological surveys of populations exposed to low level radiations. The computations have been made separately for Indian and Western populations using their representative demographic data. The western database requirements are generally found to be about half the Indian requirement.For the exposures in high background radiation areas at the rate of say 5 mSv/y, the minimum required database is 121,500 person years, in the Indian case. Similarly, for Indian occupational workers exposed at the rate of say, 10 mSv/y, it is required to observe 30,000 persons for the first 40 years or 3600 persons over their entire lifetime for obtaining statistically significant results.

Notes: A fish consumption health advisory has existed for New York Lake Ontario sport-caught fish since 1978. Our study objectives were to evaluate the effectiveness of the advisory for reaching potential target audiences and to identify appropriate advisory content, style, and dissemination methods using a risk communication planning model as an evaluation framework. We used a combination of mail surveys and personal interviews with three target audiences (opinion leaders among recreational anglers and charter boat operators, migrant farm workers, and low-income individuals) and two communicator groups (fishery experts and health care experts). The New York Lake Ontario advisory appeared to be successful in reaching and encouraging risk-mitigating fish consumption behavior in recreational angler opinion leaders and low-income individuals but not in migrant farm workers. The advisory may not be reaching two sensitive subpopulations, women of childbearing age and children. Communicators and target audiences differed in their assessments of important information to include in an advisory. The health advisory could be improved with additional information such as risk-reducing cooking and cleaning methods and by diversifying the dissemination methods to reach the variety of audiences who potentially consume Lake Ontario fish.

Notes: There has been considerable discussion regarding the conservativeness of low-dose cancer risk estimates based upon linear extrapolation from upper confidence limits. Various groups have expressed a need for best (point) estimates of cancer risk in order to improve risk/benefit decisions. Point estimates of carcinogenic potency obtained from maximum likelihood estimates of low-dose slope may be highly unstable, being sensitive both to the choice of the dose–response model and possibly to minimal perturbations of the data. For carcinogens that augment background carcinogenic processes and/or for mutagenic carcinogens, at low doses the tumor incidence versus target tissue dose is expected to be linear. Pharmacokinetic data may be needed to identify and adjust for exposure-dose nonlinearities. Based on the assumption that the dose response is linear over low doses, a stable point estimate for low-dose cancer risk is proposed. Since various models give similar estimates of risk down to levels of 1%, a stable estimate of the low-dose cancer slope is provided by ŝ= 0.01/ED01, where ED01 is the dose corresponding to an excess cancer risk of 1%. Thus, low-dose estimates of cancer risk are obtained by, risk =ŝ× dose. The proposed procedure is similar to one which has been utilized in the past by the Center for Food Safety and Applied Nutrition, Food and Drug Administration. The upper confidence limit, s, corresponding to this point estimate of low-dose slope is similar to the upper limit, q1 obtained from the generalized multistage model. The advantage of the proposed procedure is that ŝ provides stable estimates of low-dose carcinogenic potency, which are not unduly influenced by small perturbations of the tumor incidence rates, unlike q̂1.

Notes: The goal of Louisiana's 1990–1991 comparative risk project, also called the Louisiana Environmental Action Plan (LEAP), was to incorporate risk assessment into state environmental planning and policymaking. Scientists, government officials, and citizens were brought together to estimate the relative risk to human health, natural resources, and quality of life posed by 33 selected environmental issues. The issues were then ranked according to their relative estimated risks. It was hoped that this ranking of “comparative risks” would enable state policymakers to target the most important environmental problems and allocate scarce public resources more rationally and efficiently. As a result of the project, the governor issued an Executive Order forming a permanent Public Advisory Committee to continue this type of comparative risk assessment in Louisiana.

Notes: This paper presents survey results on perceived risk regarding the management of nuclear waste. Using data taken from random mail surveys of members of scientific, business, and environmental groups in Colorado and New Mexico in the summer of 1990, we examine differences between the groups in their expressed perceptions of risk and also their assessments of the certainty of their beliefs. We consider whether (a) greater uncertainty is associated with greater perceived risks and (b) whether there is greater responsiveness to new information for those whose beliefs are least certain. We find that there are connections between perceived risk and uncertainty, and there is a greater tendency to update risk assessements from a position of greater initial uncertainty. There are, however, differences between the groups as well as asymmetries in their responses to new information. The latter suggests that perceived risks will ratchet upward over time even when information is not biased toward more or less risk.

Notes: Book Reviewed in this article: Oncogene and Transgenics Correlates of Cancer Risk Assessments (NATO ASI Series, Series A: Life Sciences Vol. 232) Edited by Constantine Zervos SPSSIPC+ Made Simple By Paul R. Kinnear and Colin D. Gray Rkk: Analysis, Perception and Management (Report of a Royal Society Study Group) Floodplain Management in the United States: An Assessment Report (2 vol.) Paradoxes of Belief and Strategic Rational (Cambridge Studies in Probability, Induction, and Decision Theory) By Robert C. Koons The Chemistry of Environmental Tobacco Smoke: Composition and Measurement By M. R. Guerin, R. A. Jenkins, and B. A. Tomkins Risk-Taking Behavior (Wiley Series in Human Performance and Cognition) Edited by J. Frank Yates Statistical Methods for Survival Data Analysis By Elisa T. Lee

Notes: Techniques for performing scientific risk assessments for a wide variety of chemical and radiological hazards present in the environment and workplace are available. Speakers at a workshop sponsored by the Environmental and Public/Occupational Health Standard's Steering Group addressed both the state-of-the-art in risk assessment and areas of difficulty that require further research. The Steering Group concluded that within the limits of the available data, risk-assessment techniques are a useful tool in decision-making. In the past, many government agencies have not been effective either in listening to public concerns or in communicating technical or scientific information about risks. This has been true at all levels of government. Workshop speakers discussed some ways that government agencies can more effectively communicate with the public. The Steering Group concluded that major efforts must be made to ensure that two-way communication takes place. Thus the results of the workshop show that effective management of risk requires both a scientific assessment of risk and a responsive consideration of the public's perception of risk. Intensive efforts must be made to ensure that effective two-way communication takes place between members of the public and the appropriate government agencies.