ALBERT

Notes: The author outlines his experiences of photographic surveying, in the early years of the 1930's in the Survey of India, which involved the use of simple graphical methods of plotting.

Notes: Aerial photography may be used to quickly locate and measure the extent and severity of forest damage due to windblow. This paper describes such an application in a small area of semi-natural woodland in central Scotland after the “Great Gale” of 14th and 15th January, 1968. A 1 : 2000 scale map, showing the location and direction of fall of each windblown tree, suggests certain relationships between topography and the severity of woodland damage and gives considerable information on the airflow pattern existing over the area during the gale.

Notes: The International Society for Photogrammetry held the XIIth International Congress at Ottawa during July and August 1972. The authors comprised a panel which engaged in discussion upon the Congress at a meeting of the Photogrammetric Society on 17th October, 1972.

Notes: Distinct benefits have been obtained from the use of orthophotography in the initial planning of Scotland's sixth new town, to be located at Stonehouse, 29 km south east of Glasgow, due to a comprehensive approach to the mapping requirements. This paper discusses some of the details of the orthophotomapping project.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméL'orthophotographie s'est révélée d'un usage fort intéressant pour les études d'implantation de la sixième ville nouvelle d'Écosse (Stonehouse, 29 km au S.E. de Glasgow). On discute quelques aspects du projet d'orthophotoplan.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDeutliche Vorteile ergaben sich aus der Anwendung der Differentialent-zerrung bei der Vorplanung für Schottlands 6. neue Stadt, die in der Nähe von Stonehouse, 29 km südöstlich von Glasgow liegen soll, infolge der umfassenden Befriedigung der Anforderungen an die Kartenherstellung. Im Artikel werden einige Details des Orthophotokarten-Projektes diskutiert.

Notes: This paper describes work carried out jointly by the British Ship Research Association and the author to assess the value of photogrammetry in acquiring quality control measurements on large steel structures in the shipbuilding industry. In particular, the feasibility of using photogrammetry to resolve one of the problems of joining half ships afloat (that is the dimensional equivalence of the mating faces) is investigated.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On décrit le travail mené conjointement par la British Ship Research Association et l'auteur pour tester la valeur des méthodes photogrammétriques dans le contrôle de précision de grandes structures d'acier (industrie navale). En particulier on a cherché dans quelles mesure on pouvait utiliser la photogrammétrie pour vérifier la conformité de piéces devant entrer en jonction.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Im Artikel werden die gemeinsam vom Autor und der British Ship Research Association durchgeführten Untersuchungen zwecks Eignung der Photogrammetrie bei Gütekontrollen grosser Stahlkonstruktionen im Schiffbau beschrieben. Insbesondere wurde die Anwendungsmöglichkeit der Photogrammetrie bei der Lösung einiger der beim Verbinden schwimmender halber Schiffe auftretenden Probleme untersucht (um die Grössenordnung der Aufnahmeobjekte zu veranschaulichen).

Notes: A phototheodolite was used during the construction of Llyn Brianne dam to provide stereoscopic coverage of both upstream and downstream shoulders of the dam at each of eight stages of construction. Ground control was established on the valley sides, together with 80 targeted points at various levels on the dam as it progressed. The co-ordinates of the targeted points were determined numerically using a Wild A7. Three dimensional displacements were determined from the change of position to an average accuracy of 0–05 m. Agreement was obtained with independent and more precise measurements and comparisons are made with the upstream displacements. The assumptions of an analytical prediction technique are examined. Profile lines through the dam were also obtained numerically to record the progressing shape of the dam.

Notes: The Photogrammetric Society was honoured to be addressed by the Congress Director of the International Society for Photogrammetry during March 1974. Professor Halonen's lecture covered several aspects of current photogrammetric research in Finland. The following account contains contributions by two of his colleagues, J. Hakkarainen and H. Salmenperä, on specific aspects of lens distortion and block adjustment.

Notes: Book reviews in this article:A LAND SYSTEM ATLAS OF WESTERN KENYA. By R. M. Scott, R. Webster and C. J. Lawrance.THE OVERHAUL OF THE 1 : 2500 COUNTY SERIES OF MAPS. Ordnance Survey Professional Paper No. 25, Ordnance Survey of Great Britain, Southampton.TERRAIN ANALYSIS: A GUIDE TO SITE SELECTION USING AERIAL PHOTOGRAPHIC INTERPRETATION. By D. S. Way.PROCEEDINGS OF MAN-MACHINE INTERFACE IN PHOTOGRAM-METRY. Edited by E. Dorrer.ELEMENTARY AIR SURVEY. By W. K. Kilford.CARTOGRAPHIE GÉNÉRALE. Tome II: Méthodes et techniques de production. By R. Cuenin.INTERNATIONAL YEARBOOK OF CARTOGRAPHY (Vol. XII, 1972). Edited by E. Arnberger and F. AuradaRESOURCE SATELLITES AND REMOTE AIRBORNE SENSING FOR CANADA. Proceedings of the First Canadian Symposium on Remote Sensing, Ottawa, February 1972. Edited by D. White.LIBYA: AGRICULTURE AND ECONOMIC DEVELOPMENT. Edited by J. A. Allan, K. S. McLachlan and E. T. Penrose.ÉTUDE EXPÉRIMENTALE DE ĽAÉROTRIANGULATION SEMI-ANALYTIQUE. RAPPORT SUR ĽESSAI “GRAMASTETTEN”. Publication Officielle No. 7 de ľOrganisation Européenne ďÉtudes Photo-grammétriques Expérimentales. By P. Wiser.COORDINATE SYSTEMS AND MAP PROJECTIONS. By D. H. Maling.

Notes: Several problems are encountered when collecting traffic information by conventional methods and which leave scope for the development of more comprehensive techniques. This paper reviews the potential of different types of photography as an effective means of obtaining comprehensive traffic information. Comparisons between conventional methods and photographic methods are made. The different types of available photography are discussed, together with their uses in the field of traffic data acquisition. Finally, the paper assesses the use of automatic and semiautomatic methods of photographic data analysis in this context.

Notes: Book reviews in this article:PHOTOGRAMMETRIC GUIDE. By J. Albertz and W. Kreiling.THE READJUSTMENT OF THE RETRIANGULATION OF GREAT BRITAIN, AND ITS RELATIONSHIP TO THE EUROPEAN TERRESTRIAL AND SATELLITE NETWORKS. By V. Ashkenazi, P. A. Cross, M. J. K. Davies and D. W. Proctor.GUIDE TO SITE SURVEYING. Edited by R. Hewitt.PHOTOGRAMMÉTRIE GÉNÉRALE. By H. Bonneval.

Notes: The Ordnance Survey makes extensive use of air survey in its mapping programmes at scales of 1 : 1250, 1 : 2500 and 1 : 10 000. A short history of the development of air survey within the Ordnance Survey leads into a description of current methods including the flying, processing and aerial triangulation tasks as well as the plotting of the maps by instrumental or graphical means.

Notes: A number of proposals have been put forward for the extraction of three dimensional data from a pair of electron microscope photographs taken from different angles. The methods used have, in general, been either point by point analyses or rather inconvenient. This paper shows that an existing photogrammetric plotter of topographic accuracy can, with very simple modification, be converted to give continuous plotting facilities from certain such micrographs.

Notes: The author reminisces upon a career of almost 40 years as a practising surveyor photogrammetrist, both as a Royal Engineer officer and as a director of a commercial survey organisation. The reminiscences include service with the Survey of India, war time operations in the Middle East and South East Asia Command, and commercial surveys of all types in developing countries. Professional service with international surveying and photogrammetric organisations is also mentioned, with particular reference to the fraternal aspects of international photogrammetry.

Notes: An increasing number of applications of photogrammetry are concerned with the analysis of models, constructed to simulate proposed or existing conditions in architecture and engineering. The paper draws attention to some of these projects and reports one example in detail.

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: Earlier mathematical models that have been developed for use with data acquisition/data reduction systems in close range photogrammetry have not taken into consideration the geometry of video imagery. In this paper, a recently developed multi-application collinearity equation (MACE) model is analysed and assessed. The model is simple to apply and is adaptable to any data acquisition/data reduction system in close range photogrammetry.

Notes: The use of CCD cameras for digital photogrammetry has only slowly been taken up by the photogrammetric community. However, the pace of change is quickening with better understanding and cheaper equipment. Recently a decision was made to start some research into close range three dimensional digital measurement. The overall objective was to develop a low cost system for the automated measurement of small industrial objects. This shorter contribution describes the initial stages of this work.

Notes: This paper presents two mathematical models of the accuracy of digital terrain model (DTM) surfaces which have been linearly constructed from square gridded data, respectively with and without additional feature specific data. In these models, the accuracy of DTM surfaces is expressed as a function of a few parameters, such as slope angle, grid interval or the accuracy of raw data, which are familiar to practitioners in photogrammetry and other mapping related disciplines. These models are in a form similar to the conventional formulae for contour map accuracy and they are compared with experimental test results.

Notes: In 1987, the Scottish Office commissioned vertical aerial photography for the whole of Scotland at 1:24 000 scale. The paper describes the need for this national coverage, the physical and economic constraints and the acquisition of the photographs. The principal use of the photography, as a database for measuring land cover change in Scotland, is summarised and numerous other projects are also described. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Le Bureau des Affaires Écossaises a commandé en 1987 une couverture photographique aérienne verticale au 1:24000 sur ľensemble de ľÉcosse. On présente dans cet article les besoins qui ont motivé cette couverture, les contraintes économiques el physiques correspondantes et le déroulement de sa saisie. On donne un aperçu de la principale utilisation de ces photographies, destiniées à constituter une base de données pour la détermination des modifications intervenues en Écosse dans ľoccupation du sol; de nombreux autres projets sont également mentionées. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Im Jahre 1987 gab das Scottish Office Auftrag zur Luftbildaufnahme im Maβstab 1:24000 von ganz Schottland. Im Artikel werden die Notwendigkeit für diese vollständige nationale Bedeckung, für die physikalischen und ökonomischen Zwangsbedingungen und für die Beschaffung der Fotos beschrieben. Die prinzipielle Nutzung der Fotografie als Datenbasis zur Bestimmung der Landnutzungsänderung in Schottland wird hervorgehoben und zahlreiche andere Projekte werden ebenso beschrieben.

Notes: Maintaining the quality of aerial photographic products with time requires a simultaneous retention of both image and dimensional characteristics. These factors are prerequisites for maintaining aesthetic value and ensuring no distortion of information occurs. It is, however, the recent experience of archivists that many negatives and prints are suffering irreversible deterioration. Degradation is typified by image fading, the presence of surface crystalline deposits which obscure any image and significant dimensional distortion. This paper relates those factors which influence stability, principally temperature, relative humidity and oxygen, and correlates them to structural changes in the materials. In addition an overview is given of methods of monitoring and of inhibiting breakdown. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Pour maintenir la qualité des produits photographiques aériens dans le temps, il faut satisfaire auxproblèmes de conservation à la fois de ľimage et de ses qualités dimensionnelles. Ce sont des préalables nécessaires au maintien de la qualité esthétique du document et àľabsence de distorsion dans ses données. C'est que ľexpérience récente des archivistes a montré que nombre de négatifs et de tirages subissaient actuellement des détériorations irréversibles. Ces détériorations sont caractérisees par ľaffaiblissement de ľimage, ľapparition de dépôts cristallins en surface qui obscurcissent ľimage et ľexistence de variations dimensionelles importantes. On examine dans cet article les facteurs qui pertubent cette conservation, essentiellement la température, ľhumidité relative et ľoxydation et on les corrèle avec les changements structured des matériaux. On donne de plus un aperçu des méthodes permettant de suivre et de freiner ces altérations. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Das Gewährleisten der Qualität von Luftbilderzeugnissen in Abhängigkeit der Zeit erfordert die gleichzeitige Bewahrung sowohl der Bild- als auch der Dimensionscharakteristika. Diese Faktoren sind die Voraussetzungen zur Erhaltung des ästhetischen Wertes und gewährleisten, daβ keine Verzerrung der Informationen auftritt. Es ist jedoch neuste Erfahrung von Archivaren, daβ viele Negative und Kopien irreversible Wertminderungen erleiden. Das wird sichtbar durch das Verblassen von Bildern, das Auftreten von kristallinen Ablagerungen aufder Oberfläche, die Bilddetails verdecken und durch signifikante Dimensionsänderungen. Der Betrag bezieht sich auf solche Faktoren, die die Stabilitat beeinflussen, vor allem Temperatur, relative Luftfeuchte und Sauerstoff und korreliert diese mit strukturellen Veranderungen des Materials. Zusätzlich wird ein Überblick über Verfahren zur Materialbeobachtung und der Verminderung von dessen Verderb gegeben.

Notes: During both the First and Second World Wars, much effort was put into obtaining and interpreting aerial photographs for military reconnaissance purposes. Initially this material was classified; however, with the passing of time, much has now been declassified and is accessible to the general public. There is a large variety of information which can be of use to a number of disciplines. This material includes photographic prints, interpretation manuals, interpretation reports, plans of targets, and technical details of cameras, lenses and mountings. The use of this material will be demonstrated with examples from the United Kingdom, France and Italy, primarily for civil engineering site studies. The varied sources of this material will be discussed. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Au cours de la première et de la seconde Guerre Mondiale, on a déployé beaucoup ď efforts dans le receuil et ľ interprétation de photographies aériennes à des fins de reconnaissance militaire. Au début on classifia ces documents; mais maintenant, le temps ètant écoulé, on en a déclassifié une grande partie pour la rendre accessible au grand public. On peut ainsi y trouver toutes sortes ď informations qui peuvent être utiles à de nombreuses disciplines. Ces documents comprennent des tirages photographiques, des manuels ď interprétation, des rapports ď interprétation, des plans ď objectifs (militaires), et des détails techniques sur les chambres photographiques, leurs objectifs et leurs montures. Ľ intérêt du recours à ces documents est illustré par des examples provenant du Royaume-Uni, de France et ďItalie, essentiellement dans le domaine du génie civil pour des études de sites. On examine également les diverses origines de ces documents. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Während des 1. und 2. Weltkrieges wurde vielAufwand zur Gewinnung und Interpretation von Luftbildern für militärische Erkundungszwecke geleistet. Anfänglich wurde dieses Material unter Verschluβ gehalten, im Laufe der Zeitjedoch wurde vielesfreigegeben und ist nun der Öffentlichkeit zugänglich. Es gibt eine Vielzahl von Informationen, die für eine Anzahl von Disziplinen von Nutzen sein kann. Das Material umfaβt Fotokopien, Interpretationsmanuale, Interpretationsberichte, Pläne von Zielen und technische Details über Kameras, Objektive und Aufhängungen. Die Nutzung dieses Materials wirdan Hand von Beispielen aus dem Vereinigten Königreich, aus Frankreich und aus Italien gezeigt, und zwar vor allem für Analysen von Baustellen. Die vielfältigen Quellen für dieses Material werden diskutiert.

Notes: Low cost analytical plotters for use with 35 mm and 70 mm metric and non-metric photography are increasingly being considered as a means of introducing photogrammetry to non-photogrammetrists. One of these instruments, an Adam Technology MPS-2, recently formed the basis for a research project into the feasibility of such non-specialist use. During the project, an MPS-2 users' group was formed and many of the current users were asked to complete a questionnaire detailing their experiences with the instrument. Almost 40 users responded and their replies are given in this paper, which begins by outlining the project and goes on to discuss the comments received. The paper ends with an appraisal of the MPS-2 as seen through the eyes of its users and concludes that, considering its relatively low cost, it is definitely worthy of consideration by non-specialists. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On considère actuellement de plus en plus que les appareils de réstitution analytiques bon marché, permettant ľemploi des photographies 35 mm et 70 mm, métriques et non-métriques, constituent un bon moyen ďinitiation des non-photogrammètres à la photogrammétrie. Ľun de ces instruments, le MPS-2 de la Société Adam Technology, a servi de base à une action de recherche sur lafaisabilitéďun tel emploi par des non-spécialistes. On a formé, dans le cadre de cette action de recherche, un groupe ďutilisateurs du MPS-2, à la plupart desquels on a adressé un questionnaire leur demandant de détailler leur expérience de cet appareil. On a reçu près de 40 réponses ďutilisateurs et ľon reproduit ces réponses dans cet article. Après avoir esquisé les grandes lignes de cette action de recherche, on commente les réponses reçues. On termine sur une appréciation du MPS-2 vu par les utilisateurs et on en conclut que, étant donné son coût relativement faible, cet appareil mérite absolument ďêtre pris en compte par les non-spécialistes. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Preiswerte analytische Auswertegeräte für die Auswertung von 35 mm-und 70 mm-Fotos, die mit Meβkammern und Nichtmeβkammern aufge-nommen wurden, werden zunehmend als Mittel zur Einführung der Phologrammetrie bei Nichtphotogrammetem angesehen. Eines dieser Geräte, ein MPS-2 von Adam Technology, bildete kürzlich die Grundlage für ein Forschungsprojekt zum Nutzen solcher Anwendungen für Nicht-spezialisten. Während des Projektes wurde eine MPS-2-Nutzergruppe gebildet und viele der gegenwärtigen Nutzer wurden gebeten, einen Fragebogen zu vervollständigen und ihre Erfahrungen mit dem Gerät mitzuteilen. Zunächst wird das Projekt skizziert, und dann werden die erhaltenen Kommentare diskutiert. Der Artikel schlieβt mit einer Bewertung des MPS-2, wie er mit den Augen seiner Nutzer gesehen wird und schluβfolgert, daβ er unter Beachtung seiner relativ geringen Kosten deutlich die Aufmerksamkeit der Nichtspezialisten verdient.

Notes: The evolution of quality assurance at the Ordnance Survey of Great Britain (OS) is described. Quality control methods have been adopted to cope with the change from graphical to digital products and processes, but the human inspector remains indispensable. Following an agreement that the OS will archive large volumes of digital data captured by public utility contractors, quality assurance procedures for the acceptance of batches of digital maps have been based on an elaboration of standards BS 6001 (IS02859). A quality assurance certification scheme for land survey organisations based on BS 5750 (ISO9001) is under discussion. However, following recent government initiatives in quality management, the OS is now committed to the philosophy of total quality management and registration schemes for quality assurance could eventually become obsolete. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Cet article traite de ľévolution de ľassurance-qualitéàľOrdnance Survey (OS) de Grande-Bretagné. On a adopté a ľOS des méthodes de contrôle-qualité permettant de faire face aux changements résultant du passage de la forme graphique à la forme numérique pour les procédés el les produits, tout en conservant unepart ďintervention humaine indispensable dans les controles. Comme suite à une convention passée avec les services publics selon laquelle ľOS doit archiver ďimportantes quantités des donnees numiriques que ceux-ci auront receuillies, on se conformera à un système de normes BS 6001 (ISO 2859) pour les procédés ďassurance-qualité lors de la recette technique des lots de cartes numériques. La discussion porte actuellement sur un projet de certification ďassurance-qualité et de registre pour les organismes de levé foncier, en se basant sur la norme BS 5750 (ISO 9001). Toutefois, aprés les récentes initiatives gouvernementales en matière de gestion de la qualityé, ľOS se trouve maintenant confrontéà la philosophie ďune gestion de la qualityé-totale, ce qui pourrait finalement rendre périmés les projets ďassurance-qualité actuels. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Es wird die Entwicklung der Qualitätssicherung beim Ordnance Survey (OS) in Groβbritannien beschrieben. Dazu wurden Verfahren zur Qualitätskontrolle entwickelt, die dem Wechsel von graphischen zu digitalen Erzeugnissen und Prozessen genügen, aber der menschliche Faktor bleibt dabei unentbehrlich. Entsprechend einer Vereinbarung, wonach der OS groβe Mengen digitaler Daten archiviert, die durch öffentlich bestellte Vertragspartner erfaβt wurden, beruhen die Verfahren zur Qualitätssicherung für die Annahme von Datensätzen digitaler Karten auf der Ausarbeitung der Standards BS 6001 (ISO 2859). Diskutiert wird gegenwärtig ein auf dem Standard BS 5750 (ISO 9001) basierendes Nachweisschema zur Qualitätssicherung und ein Register für Organisationen, die sich mit Landvermessungen beschüftigen. Folgt man jedoch jüngsten Initiativen der Regierung in bezug auf die Behandlung der Qualität, so ist der OS der Philosophie zur totalen Qualitätsverwaltung und Registratur verpflichtet, denn die Qualitätsgewährleistung könnte möglicherweise unüblich werden.

Notes: Photogrammetric measurements within environmental test chambers which incorporate viewing ports constitute an application of multi-media photogrammetry. Perturbations to the incident bundles of rays due to refraction must therefore be taken into account. In this paper, refraction compensation for the case of antenna measurements within thermal vacuum chambers is discussed. Correction models applicable to the camera invariant refracting surfaces of a glass window and vacuum chamber are reviewed, especially error compensation using the approach of analytical selfcalibration. Results of a sequence of measurements of a satellite antenna are then analysed to illustrate the high measurement accuracies which are afforded by the selfcalibration approach. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Les déterminations photogrammétriques dans un environnement de caissons ď essais munis de hublots de visée, constituent une application de la photogrammetrie à trovers des milieux multiples. II y a lieu par conséquent de tenir compte des perturbations que subissent lesfaisceaux de rayons lumineux incidents par suite de la réfraction. On examine dans cet article la compensation de la réfraction dans le cas de mesures sur des antennes placées dans des enceintes thermiques sous vide. On analyse les modèles de correction applicables aux surfaces réfractantes invariantes de la chambre photographique et de ľ enceinte à vide, comprenant des fenêtres en verre, en s'attachant plus particulièrement à une compensation ď erreurs basée sur des méthodes ď auto-étalonnage analytique. On présente ensuite les résultats ď une série de mesures portant sur une antenne de satellite, qui illustrent le haut degré de précision atteint par cette méthode ďauto-étalonnage. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Photogrammetrische Messungen innerhalb von Umwelt-Testkammern, die auch Öffnungen zum Durchblick enthalten, stellen eine Anwendung der Multimedien-Photogrammetrie dar. Demzufolge müssen Störungen wegen Refraktion bei den Aufnahmestrahlenbündeln berücksichtigt werden. Im vorliegenden Beitrag wird die Kompensation der Refraktion für Antennenmessungen in thermalen Vakuum-Kammern diskutiert. Korrekturmodelle, die auf die kamerainvarianten brechenden Oberflächen eines Fensterglases und die Vakuum-Kammer angewandt werden können, werden analysiert, besonders unter dem Gesichtspunkt, daß eine Fehlerkorrektur mittels Selbstkalibrierung erfolgt. Dann werden Ergebnisse einer Folge von Messungen an der Satellitenantenne analysiert, um die hohe Meßgenauigkeit darzustellen, die aus dem Ansatz zur Selbstkalibrierung resultiert.

Notes: This paper describes some experimental investigations into the variation of digital terrain model (DTM) accuracy with sampling interval, based on data acquired using stereophotogrammetric methods. The main factors affecting DTM accuracy are reviewed and various alternative schemes for carrying out experimental tests on DTM accuracy are outlined. Detailed information is given about the test areas, source data sets and check point data sets, followed by a discussion concerning the special design of this experiment. The experimental results are reported and, finally, a critical analysis of the test results is presented.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On presente dans eel article quelques études expérimentales sur la variation de ľ exactitude ďun modèle numerique du terrain (MNT) en fonction de ľintervalle ďéchantillonnage de données obtenues à partir de méthodes stéréophotogrammétriques. On examine les facteurs principaux qui interviennent sur ľ exactitude ď un MNT et ľ on esquisse divers projets permettant de mener au choix des essais expérimentaux sur ľ exactitude ďun MNT. On fournit des informations détaillées sur les polygones ď essai utilisés, lesjeux de données concernant les points de vérification et ceux de l'altimétrie initiale, suivies ďune présentation de la conception particulière de ces études. On décrit les résultats expérimentaux obtenus et ľ on termine cet article par une analyse critique des résultats de ľ essai. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Im Artikel werden einige experimentelle Untersuchungen zur Variation der Genauigkeit von Digitalen Geländemodellen (DTM) beschrieben, wobei ein Rasterintervall verwendet wurde, das auf stereophotogrammetrischer Datenerfassung basierte. Es werden die Haupteinfluβfaktoren auf die Genauigkeit der DTM betrachtet und verschiedene alternative Wege zur Testung der DTM-Genauigkeit skizziert. Detaillierte Angaben erfolgen zu den Testgebieten, den Quelldaten-Sätzen und den Datensätzen der Kontrollpunkte mit anschlieβenden Ausführungen zur speziellen Gestaltung dieses Versuchs. Die Versuchsergebnisse werden angegeben, und abschlieβend erfolgt ihre kritische Analyse.

Notes: The broad requirements of the geomorphologist for original mapping are reviewed. The extent to which aerial photogrammetry can meet these requirements is exemplified through typical approaches and mapping products in fluvial, coastal and glacial specialisms.

Notes: As part of the measurements of desert terrain characteristics in the United Arab Emirates, made in support of a study of airborne radar, close range vertical stereophotographs of various natural surfaces were taken with a pair of Hasselblad MK70 metric cameras. The technique is described and the constraints imposed by the ground conditions and the need for rapid measurements are explained. Various terrain types are illustrated and the method is described whereby variables summarising surface roughness and surface slope were generated from profiles of the microrelief. From a more general discussion of current equipment and geomorphological applications of close range photogrammetry, it is concluded that this flexible technique is presently under utilised by field scientists.

Notes: The French topographic database is a three dimensional database whose content is very near to that of the IGN 1:25 000 scale maps. It has a metric accuracy and is designed to have three aims (maps at scales of 1:25 000 and 1:50 000 and the topographic part of the cadastral map at 1:5000 scale, providing located structured data). The structure, including topology information, is described. The process of data capture is based on photogrammetry and field completion. Experiments concerned with revision are being made in order to define the methodology precisely.

Notes: A mathematical model for pass processing of SPOT imagery is formulated. It is based on the fact that during one pass, the image data stream from each of the instruments in SPOT forms one single very long image. The geometry of this extended image can thus be rectified with as few control points as for only one scene if orbital constraints and attitude measurements are properly taken into consideration. SPOT imagery is, however, not available as this single long image, but only sectioned into scenes. This creates problems which are accounted for in the solution. The possibility of gaps in the sequence of scenes is also taken into consideration. Extrapolation over gaps is of special interest and, by investigating attitude variability, it is shown that extrapolation is successful over multiple scene gaps which is also verified in a real data test.

Notes: Inner constraints, generalised matrix inverses and S-transformations are described in relation to least squares estimation of spatial positions. A simple example is used to illustrate some of the theory. The various roles and properties of covariance functions and matrices are presented with a discussion of their practical determination and use in least squares interpolation and collocation.

Notes: This review of digital image processing refers to the pioneer work of Helava and Hobrough which has influenced the most recent trends in photogrammetry. The author goes on to discuss aspects of digital image acquisition, storage and display, as well as digital photogrammetric procedures and systems.

Notes: Site procedures, instrumentation, analytical methods and accuracies achieved are described for the measurement of the deformation of a military steel bridge under load in a test gantry. Some remarks concerning the advantages and disadvantages of photogrammetry as a method of industrial measurement are made.

Notes: An account is given of the importance of photogrammetric techniques in industrial three dimensional problems and the way in which obtaining data in this environment differs from the more common applications. Possible system arrangements are discussed. The particular choice at Imperial College and the resulting system speed and accuracy are presented.

Notes: Lasertrace is a high accuracy measurement system for the remote, non-contact determination of position, velocity, or acceleration in two or three dimensions. It uses advanced two axis laser steering technology to locate and measure the angular position, from itself, of an identified point on an object under investigation. If the object subsequently moves, the steerable laser beam actually tracks the point providing updated position coordinates as it does so. An operating window of 40° in both axes guarantees system versatility in a wide range of applications.

Notes: Optical triangulation is used in the human visual system and surveying tacheometers to estimate distance. This method is now used in systems with solid state sensors which enable fast measurement of distance with sufficiently high accuracy for many applications. City University has built on past experience to develop the optical triangulation technique to gather data appertaining to cross sections or profiles of structures in the range 0.2 m to 20 m radius from the measurement axis. Results obtained using three prototypes are given.

Notes: The author, a research and development manager at Ordnance Survey, reviews current developments in photogrammetry including the automatic correlation of image points for aerial triangulation, digital photogrammetric map revision, mapping from SPOT imagery and progress in aerial photography.

Notes: This study of coastal air survey draws together the main characteristics of the coastal zone, scientific sites of interest, statutory spheres of responsibility, existing coastal photography and survey, and evidence of survey practices by many with responsibilities in these environments. In contrast to the surveyor/photogrammetrist steeped in survey techniques and map use, the majority of people who commission and use air photographs and photogrammetric mapping have very different backgrounds and interests and have widely differing objectives. They come largely from the disciplines of economics, planning, engineering, geography, biological sciences and accountancy. They, too, have their own view of the value of air survey and the analysis here of the trends in demand and use for such material suggests that these sources of information play only a minor and occasional part in their everyday work.

Notes: This paper presents all the stages involved in the procedure for the determination of the shape of a fuel assembly, which is an essential part of a nuclear power plant and can only be handled underwater. Phototriangulation is used to obtain orientation elements, taking into account light refracting surfaces. Stereomodels are then set up for analytical restitution and the shape parameters for the object can be obtained. The project is a typical example of high precision underwater photogrammetry.

Notes: Book review in this Article:PHOTOGRAMMETRY APPLIED TO SURVEYS OF MONUMENTS AND HISTORIC CENTRES. By M. Carbonnell. English translation by R. W. A. Dallas and K. V. Parker.ELECTRONIC DISTANCE MEASUREMENT. Third Edition. By J. M. Rüeger.RECONNAISSANCE, ASTRONOMY, REMOTE SENSING AND PHOTOGRAMMETRY. Edited b I Hirschberg.SATELLITE DATA: PROCESSING, ARCHIVING AND DISSEMINATION. Volume 1 Applications and Infrastructure. By D. R. Sloggett.SATELLITE DATA PROCESSING, ARCHIVING AND DISSEMINATION. Volume 2 Functions, Operational Principles and Design. By D. R. Sloggett.GPS: A GUIDE TO THE NEXT UTILITY. By J. Hurn.RADARGRAMMETRIC IMAGE PROCESSING. By F. W. Leberl.REMOTE SENSING OF SOILS AND VEGETATION IN THE USSR. By P. J. Curran, G. M. Foody, K. Ya. Kondratyev, V. V. Kozoderov and P. P. Fedchenko.ENGINEERING SURVEYING TECHNOLOGY. Edited by T. J. M. Kennie and G. Petrie.ACCURACY OF SPATIAL DATABASES. Edited b M. F. Goodchild and S. Gopal.CARTOGRAPHY PAST, PRESENT AND FUTURE A Festschrift for F. J. Ormeling. Edited by D. W. Rhind and D. R. F. Taylor.HIGH PRECISION NAVIGATION. Edited by K. Linkwitz and U. Hangleiter.INVENTORY OF WORLD TOPOGRAPHIC MAPPING. Volume 1 Western Europe, North America and Australasia. Compiled by R. Böhme.ADVANCED PHOTOGRAPHY. B M. Langford.PHOTOGRAMMÉTRIE ET SYSTÈMES D'INFORMATION DU TERRITOIRE. Directeur de la publication O. Kölbl.

Notes: The author describes the photogrammetric equipment in use by the Royal Commission on Historical Monuments (England), the methods used and the work that is being done in architectural recording. The difficulties and the possibilities of future architectural work in the United Kingdom are discussed and the achievements of some other countries in this field are reviewed.

Notes: Four papers were read during the first symposium to be held by the Photogrammetric Society, at the University of Birmingham on 3rd and 4th April. Major General R. LI. Brown examined the staff structure of the organisations engaged upon the photogrammetric production of maps in the United Kingdom. Mr. J. R. Hollwey outlined the syllabus for a new Higher National Certificate in photogrammetry during a session which was devoted to education and qualifications. Subsequently, Professor A. J. van der Weele explained the evolution of the courses at ITC. By way of contrast, Professor E. H. Thompson attempted a forecast of developments in photogrammetry during the next decade. The papers succeeded in initiating prolonged discussion among the 80 members who attended.

Notes: A method is described for determining wind vectors in the lower atmosphere from terrestrial stereophotography. The photographs were taken with specially adapted aerial cameras using the normal or parallel averted case with horizontal camera axes. The most favourable photographic registration was obtained on ORWO UT 16 colour reversal film. Photograph co-ordinates and horizontal parallaxes were measured and recorded on punched tape with the Zeiss (Jena) stecometer. Vector components, which were calculated from co-ordinate differences, and a statistical analysis were obtained by using an electronic computer.

Notes: The current methods for describing and comparing shapes of teeth have a number of inadequacies which lead to inaccuracy and misinterpretation. A method is described which depends on co-ordinate information. Stereoscopic microphotography of teeth crowns is used to take co-ordinates of up to 600 points on the tooth surface. Mathematical surfaces are fitted to the co-ordinates by the method of least squares and analysed by trend surface analysis. The results show that this is a useful method of describing a complex shape, although there are problems which render comparison more difficult.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLes méthodes qu'on utilise généralement pour décrire et comparer les formes des dents sont de par leur nature imprécises et peu sûres. On décrit une méthode basée sur l'utilisation de coordonnées tridimensionnelles. A partir de micro-stéréogrammes de couronnes dentaires, on relève les coordonnées de près de 600 points de la surface de la dent. Ce semis est ensuite lissé par des surfaces mathématiques et étudié par les méthodes de l'analyse des surfaces. On conclut qu'il s'agit d'une utile méthode de description d'une forme complexe, quoique les comparaisons de dent à dent restent difficiles.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie gegenwärtigen Methoden zur Beschreibung und zum Vergleich von Zahnformen weisen eine Reihe von Unzulänglichkeiten auf, die zu Ungenauig-keiten und Fehlinterpretationen führen. Es wird ein auf der Koordinatenin-formation beruhendes Verfahren beschrieben. Dabei wird die Stereomikro-photographie von Zahnkronen zur Ermittlung der Koordinaten von bis zu 600 Punkten auf der Zahnoberfläche angewendet. Die mathematische Oberfläche wird mit Hilfe der Methode der kleinsten Quadrate bestmöglich den gegebenen Koordinaten angepasst und durch Oberflächentrendanalyse überprüft. Die Ergebnisse zeigen, dass es sich um ein brauchbares Verfahren zur Beschreibung komplexer Formen handelt, obwohl es einige Probleme gibt, die den Vergleich erschweren.

Notes: Book Reviewed in this article:TERRAIN EVALUATION. By C. W. Mitchell.ENVIRONMENTAL REMOTE SENSING: APPLICATIONS AND ACHIEVEMENTS. By E. C. Barrett and L. F. Curtis.MULTILINGUAL DICTIONARY OF TECHNICAL TERMS IN CARTOGRAPHY. Compiled by the International Cartographic Association.THE EARTH FROM SPACE. By J. Bodechtel and H. G. Gierloff-Emden.CARTOGRAPHIC DESIGN AND PRODUCTION. By J. S. Keates.

Notes: In recent years analytical aerial triangulation in the Royal Australian Survey Corps has evolved to an advanced stage. Current procedures are described and future possibilities explored.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Ces dernières années les techniques d'aerotriangulation analytique, dans le Royal Australian Survey Corps ont beaucoup progressé. On décrit les méthodes employées et on fait quelques prospective.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammensfassung In den letzten Jahren hat die analytische Aerotriangulation beim Royal Australian Survey Corps einen bedeutenden Stand ereicht. Die gegenwärtigen Technologien werden beschrieben und künftige Möglichkeiten untersucht.

Notes: The authors describe the photogrammetric procedures involved in the production of 1 : 50 000 scale mapping within the Directorate of Overseas Surveys, making specific reference to a project in Ethiopia.

Notes: The paper reviews the status of the optical transfer function (OTF) as a potential standard method for measuring the definition of photogrammetric camera lenses. The nature of the OTF and its relation to resolving power are explained. The limited success in obtaining agreement in international comparisons of OTF measurement and the programme of the Scientific Instrument Research Association group research project on the O TFare summarised. Some of the difficulties envisaged in applying the OTF as an ISP standard are discussed.

Notes: Orthophotomaps at 1 : 2500 scale, contoured at 1 m vertical intervals, have been produced for an area of 52 km2 from 1 : 10 000 scale photography especially flown for the project. Planimetric and height information on published Ordnance Survey 1 : 2500 scale maps was used as control for the aerial triangulation on which the orthophotomapping was based.

Notes: The paper describes a method for the automatic determination of height profiles in the stereomodel. The model is scanned automatically in epipolar planes. The photographic densities are recorded. The density values are correlated, either on or off line, to obtain the height profiles. The method was developed for the analytical plotter but can be applied to other photogrammetric instruments.

Notes: Experiments are described which compare point transfer from one photograph to another by stereoscopic and non-stereoscopic procedures. It is shown that, whereas it may be possible to achieve very high accuracies by both methods, the former method is more dependent for its accuracy on a high observer skill and is also more prone to occasional mistakes in identification.

Notes: Methods and results of practical applications of block adjustment by independent model cadastral surveys are described. The wider implications of the results are assessed in conjunction with current research trends in the adjustment of extremely large blocks for small scale mapping and in the use of the bundle adjustment method.

Notes: Digitising from a photogrammetric instrument can be controlled by a unit specially designed for this purpose, or by a digital control computer. In the latter case, the digitising system is more flexible since alterations and additions to the real-time programs can easily be made to effect different digitising applications. The control computer can also be used in processing the digitised data.The use of such digital control in photogrammetry is as yet limited. The reasons are examined. The characteristics and real-time requirements of a computer controlled digitising system are stated. Different digitising and recording modes, identification numbers and editing arrangements are then given to illustrate the flexibility and limitations of such a system.

Notes: The article discusses a general classification system applicable to digital ground models (D.G.M.) as used in highway design. Examples of the various categories are given, together with details of some advantages and disadvantages. The place of the D.G.M. in the highway design system is described in conjunction with traditional methods. The relationship between accuracy, density and economy of D.G.M. systems is examined. Finally an experiment is described which investigates the accuracy of various D.G.M. systems; it is being conducted by the Transport and Road Research Laboratory.

Notes: Book reviews in this article:OPTIMIZATION TECHNIQUES IN LENS DESIGN. By T. H. Jamieson.ADJUSTMENT BY LEAST SQUARES IN GEODESY AND PHOTOGRAM-METRY. By R. A. Hirvonen.AERIAL PHOTO-ECOLOGY. By J. A. Howard.PROCEEDINGS OF THE ISP COMMISSION IV SYMPOSIUM 1970. Editor J. Kure.

Notes: The use of aerial photography for hydrographic requirements is discussed, with particular reference to current circulation in an all water area. The paper examines the criteria and limitations imposed by an environment which is alien to normal topographic photogrammetry.