The Photogrammetric Record

Published by Wiley
Online ISSN: 1477-9730
Publications
Article
This paper presents a generic scheme to extract traffic information from both optical satellite imagery and optical airborne image sequences. The extraction is based on an explicit semantic model of traffic, from which, depending on the characteristics of the input data, different strategies for vehicle detection, vehicle queue extraction and motion estimation are derived. The model comprises different scales to exploit the scale-dependent properties of traffic imaged by optical sensors. It is furthermore extended by context information to include knowledge about background objects as well as metadata from a road database in a consistent way. Various tests with different input data have been carried out and compared with manually acquired ground truth data of vehicles and vehicle tracks. The results show clearly the high potential of airborne and spaceborne traffic monitoring, but also indicate room for methodological improvements and exhibit some inherent sensor-related drawbacks.
 
Article
The camera is designed for work at great heights and calls for a precise and exacting specification and some novel features. The lens is specially designed. A filter is incorporated in a special coating of one of the lens surfaces. Dessicators and breathers are provided. A specially designed pressure plate ensures very close contact of the film with a register glass bearing an engraved reseau. In place of the normal magazine, film cassettes are used. The removable inter-lens shutter is of unusual design to meet a rigorous specification. Remote control is provided. The mounting of the camera and certain minor details and adjustments have yet to be finalised in the prototype.
 
Article
Unmanned aerial vehicle (UAV) photogrammetry has been used in a growing number of diverse applications across different scientific disciplines. Early applications of UAVs included cultural heritage and archaeology, mainly for the documentation and modelling of monuments, buildings and landscapes. In this paper, the focus is on the application of UAVs for documenting archaeological excavations. As excavating is a dynamic process and the objects to be acquired can change significantly within a few hours, UAVs can provide a suitable alternative to traditional measurement methods such as measuring tapes and tachymeters. Nevertheless, the image processing steps have to be automated, as a large number of resulting materials, usually sketches, maps, ortho-images and 3D models, need to be available quickly. In order to accelerate the processing workflow, an interface between the UAV ground control software and various photogrammetric software packages was developed at ETH Zurich, which allows for an efficient management and transfer of orientation, trajectory and sensor data for rapid project set up.
 
Article
A few of the many interesting aspects of the mind, life and work of Robert Hooke (1635-1703) are discussed, particularly some that are relevant to opto-mechanical photogrammetric plotters and cameras. Evidence from primary and secondary sources is presented which indicates that Hooke devised instruments with optical and mechanical components which later came to be used in photogrammetric plotters, that he recognized the value of perspective projection in accurate recording of terrain, and devised a “Picture-Box” for that purpose. The question of how far he progressed in photography in experiments with purple dyes is left open. These “photogrammetric” activities of Hooke's are shown to have been only a small part of his work in London which included duties as Curator of Experiments to the Royal Society, Professor of Geometry at Gresham College, and Surveyor to the City of London Authorities following the Great Fire in 1666.
 
Article
A centenary tribute is paid to a soldier and sportsman, surveyor and inventor, artist and humorist. Vivian Thompson served in two wars, the second of which resulted in his untimely death. His Stereo-plotter, first described to the Royal Geographical Society in 1908, remains as a memorial and as a reminder of a great opportunity which was lost. Hommage est rendu à un soldat, à un sportsman, géomètre, inventeur et à un artiste plein d'humour. Vivian Thompson participa à deux guerres, dont la dernière n'est pas sans relation avec sa mort. Son restituteur, décrit à la Royal Geographical Society en 1908, reste comme un témoin d'une grande occasion perdue. Es erfolgt eine einhundertjährige Würdigung für einen Soldaten und Sportler, Geodäten und Erfinder, Künstler und Humoristen. Vivian Thompson diente in 2 Kriegen, wobei er bedauerlicherweise im letzten einen vor-zeitigen Tod fand. Sein im Jahre 1908 zum ersten Male in der Royal Geographical Society beschriebenes Stereokartiergerät bleibt als ein Denkmal erhalten und erinnert an eine grosse Möglichkeit, die verschenkt wurde.
 
Article
In 1904, Dr. H. G. Fourcade compiled the first recorded topographic map made using analytical stereophotogrammetric methods. This paper describes how, in 1985, the stereophotography was repeated in very close proximity to Fourcade's original camera base using a modern metric camera. A new topographic map was compiled by computer graphics from stereoscopic observations made on a modern stereocomparator. A direct comparison of the two sets of interpolated contour lines demonstrates that Fourcade produced a highly accurate map covering part of Devil's Peak which is adjacent to Table Mountain near the city of Cape Town.
 
Article
The well established use of air survey photography in Ordnance Survey mapping programmes since the Second World War contrasts markedly with spasmodic experiments in earlier years. Even so, the author laments the absence of photography which is known to have been taken in the 1920s and 1930s and which underlines the need for appropriate preservation of air photography of the recent past. L'utilisation de la photographie aérienne qui fait désormais tout à fait partie intégrante de programmes cartographiques de I'Ordnance Survey, contraste de façon notable avec les à-coups qui ont caractérisé les expériences des premières années. L'auteur n'en déplore pas moins I'absence des photographies que l'on sait avoir été prises dans les années 1920 et 1930; cela souligne la nécessité d'une conservation adéquate des photographies aéiennes remontant à un proche passé. Die nach dem 2. Weltkrieg gut organisierte Nutzung der Aerophotogrammetrie beim Ordnance Survey kontrastiert markant zu den verkrampften Versuchen in früheren Jahren. Desgleichen beklagt der Autor das Fehlen von Fotos, die in den 20er und 30er Jahren aufgenommen wurden, was die Notwendigkeit einer geeingneten Aufbewahrung von Luftbildern aus der jüngsten Vergangenheit zeigt.
 
Article
A scholarly account of the formative discussions, the founding and the first 20 years of the Photogrammetric Society was published in 1971 and republished in 1974. This present review concentrates on the latter years of the life of the Photogrammetric Society prior to its merger with the Remote Sensing Society in 2001. The authors joined the Photogrammetric Society in 1960 and were conspicuous in its affairs for many years. Although both occupied the Society's presidential chair, they also fulfilled several other roles in its efficient management. Atkinson's first contribution to the Photogrammetric Record was published in 1968 and Newton's in 1971.
 
Article
Since the mid-1960s, the Ordnance Survey of Ireland, whose headquarters are in Dublin, has undergone great technological change. This paper emphasises the photogrammetric aspects of that change and outlines how a sophisticated range of modern equipment is used in the supply of survey data for the Irish Republic.
 
Article
Following a period of considerable debate and change in the organisation of the Ordnance Survey, the use of photogrammetric methods and equipment in the support of its mapping tasks during the period 1972–1986 is reviewed.
 
Article
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. 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. 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.
 
Article
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.
 
Article
The use of small computers for on line data processing in photogrammetry has developed from the desktop calculators of the early 1970s to the microcomputers of today. The restrictions of machine code programming, small memory and limited display have been overcome. Software has been written for the PI-1A monocomparator using the BBC microcomputer for a calibration test, relative orientation, and strip formation and adjustment in the on line mode. This low cost system is suitable for training inexperienced operators or students in analytical photogrammetry, with the sequence of observation guided by operator prompts and with error checking computations displayed. Re-observations can be made on line and acceptable observations stored for input to the strip adjustment program or subsequent block adjustment.
 
Article
During a project concerned with DEM generation using SPOT stereoscopic imagery, difficulties were experienced when using Level 1B stereopairs for the task. This paper presents a mathematical solution to overcome this problem which has been implemented at the University of Glasgow. Results are included from experimental tests which were carried out over a test field in Jordan using this solution. These tests used five SPOT Level 1B stereopairs together with a single SPOT Level 1A stereopair for comparative purposes. The residual errors at the ground control points and independent check points are given and show that a satisfactory solution was achieved.
 
Article
This paper evaluates the effects of JPEG 2000 compression on automated digital surface model (DSM) extraction, using the area-based matching technique. Two stereopairs of aerial photographs, which have different photo scale, pixel size, and topographic type, are used as the images for the experiments. In the experiments, the DSM generated from the uncompressed image is set as the reference, and the elevation accuracy is computed for a range of compression ratios (2:1 to 100:1). The results show that the employed indices of image quality based on the JPEG 2000 compression are clearly superior to the commonly used JPEG compression technique - especially for high compression ratios. However, the elevation accuracy varies with the compression ratios. Also, JPEG 2000 compression does not have a significant influence on the percentage of the successful matching rate. In addition, a near linear fall-off is observed in extracted DSM accuracy with increasing compression ratios. © 2005 The Authors. Journal Compilation 2005 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
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.
 
Article
Communication between the photogrammetrist and the land surveyor is essential for the overall success of a large scale mapping project, but each will have individual responsibility for specific stages of the project. Liaison is also required to achieve the maximum accuracy for heighting. Other interface areas between photogrammetry and surveying include the use of scanned images, airborne GPS and the development of the GIS market. The author emphasizes that co-operation will be vital for 21st century mapping, not only between technical disciplines, but also between the commercial, government and academic sectors of the mapping industry.
 
Article
E. H. Thompson, the pre-eminent British photogrammetrist, died 25 years ago. His memory has been perpetuated in several ways. An analogy is drawn between the design of a 21st century digital air survey camera and that of Thompson's multi-lens camera of the 1930s.
 
Article
With the completion of its programme to produce a national series of 1:2500 scale maps of rural areas, the Ordnance Survey is now faced with the major task of maintaining it up to date and making the revision information available to map users. The organisation and techniques for this are discussed, as are a number of innovations which are being considered. Avec l'achèvement du programme de réalisation de la série cartographique nationale à l'échelle du 1:2500 des régions rurales, l'Ordnance Survey doit maintenant faire face au maintien à jour de cette série et à la mise à disposition des usagers des données de révision, ce qui va constituer sa tâche principale. Une discussion sur l'organisation et les techniques correspondantes est fournie, prenant en compte l'examen de nombreuses innovations. Nach Fertigstellung der Kane 1:2500 von ländlichen Gebieten besteht für den Ordnance Survey jetzt die Aufgabe, diese Karte laufend zu halten und die Ergänzungen den Kartennutzern bereitzusteller. Diskussion der Organisation und Verfahren dafür sowie einiger Neuerungen, die in Erwägung gezogen werden.
 
Article
The Ordnance Survey's approach to the revision of the 1: 2500 scale series is discussed, with particular emphasis on the variety of photogrammetric methods which are used. The special problems of re-casting existing maps onto the National Grid projection, without losing the value of the existing detail, are outlined whilst emphasising the need to complete the revision with maximum speed to an adequate accuracy for a minimum cost. On expose les méthodes de l′ Ordnance Survey en matière de révision des levés au 1: 2500; on examine le problème de l'adaptation des levés existants au système cartographique national, sans qu'il y ait perte de richesse. Es wird ein Versuch des Ordnance Survey zur Laufendhaltung der Karte 1: 2500 beschrieben, wobei die verschiedenen photogrammetrischen Verfahren, die angewendet wurden, besonders betont werden. Die speziellen Probleme der Einpassung bestehender Karten in das Nationale Gitternetz ohne den Verlust der vorhandenen Details werden skizziert, wobei hervorgehoben wird, dass die Revision mit maximaler Geschwindigkeit ohne Genauigkeitsverlust bei minimalen Kosten durchgeführt werden muss.
 
Article
Three-dimensional modelling from single images remains an interesting topic of investigation in the research community, even though range sensors are becoming a common alternative for the generation of 3D information. The interest in single-image-based modelling is motivated by a wide spectrum of applications such as cultural heritage, civil engineering, urban planning and even criminology. In this paper a complete new production flowline is presented for modelling based on a single image. The modelling process consists of a series of familiar steps in photogrammetry and computer vision: feature extraction, vanishing point computation, camera self-calibration, 3D reconstruction and dimensional analysis. In particular, the methodology developed for single-image-based modelling takes a scientific approach combining several proven techniques with robust estimators. Finally, in order to demonstrate its capabilities, the reported examples include several real situations applied in different contexts. © Journal Compilation © 2008 Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
Direct solutions are very attractive because they obviate the need for initial approximations associated with non-linear solutions. The direct linear transformation (DLT) establishes itself as a method of choice for direct solutions in photogrammetry and other fields. The use of the DLT with coplanar object space points leads to a rank deficient model. This rank deficient model leaves the DLT defined up to a 2D projective transformation, which makes the direct retrieval of the exterior orientation parameters (EOPs) a non-trivial task. This paper presents a novel direct algorithm to retrieve the EOPs from the 2D projective transformation. It is based on a direct relationship between the 2D projective transformation and the collinearity model using homogenous coordinates. This representation offers a direct matrix correspondence between the 2D projective transformation parameters and the collinearity model parameters. This correspondence lends itself to a direct matrix factorisation to retrieve the EOPs. An important step in the proposed algorithm is a normalisation process that provides the actual link between the 2D projective transformation and the collinearity model. This paper explains the theoretical basis of the proposed algorithm as well as the necessary steps for its practical implementation. In addition, numerical examples are provided to demonstrate its validity. © 2006 Battelle Memorial Institute. Journal Compilation 2006 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
Mechanical calibration and alignment are fundamental steps in the development of any new aerial photogrammetric scanner. One aim of a film scanner in the digital era is to digitise the accumulated historic archives of images belonging to photogrammetric institutes. The present analysis is centred on a scanner with a translating 2D array camera. Two phases of equal importance can be outlined: the first phase is the alignment of all the mechanical parts inside the scanner, and the second is mechanical calibration, when the systematic effects in the camera positioning are measured and compensated. Among the design requirements of this scanner was to avoid the need for geometrical modification of the scanned images: they should be acquired in the correct position and not require a posteriori correction with a software routine. The proposed solutions lead to a final result of a metrologically satisfactory scanner with a geometric uncertainty of 2...μm or less throughout the frame (250...mm....×....250....mm), a value definitely smaller than the pixel size (10...μm/pixel). © 2010 The Authors. Journal Compilation © 2010 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
A review is provided of the techniques and applications of very close range photogrammetry to engineering measurements in the electricity supply industry. Starting from a definition of very close range photogrammetry by consideration of depth of field, the techniques of measurement in the range 300 mm to 3 m are discussed with an analysis of four practical examples; two examples relate to the confirmation of continued structural integrity of nuclear reactor components by remote photogrammetric measurement, one uses the technique for measuring creep stress for component life assessment and one uses it for the baseline measurements of insulation coverplates in a nuclear reactor pressure vessel. Emphasis is given to the mathematical modelling of the cameras employed and their subsequent calibration. The development of a universal calibration facility for all cameras working in this range is described.
 
Article
The full provision of ground control points for oblique, small format photography used for mapping purposes is uneconomic because each photograph covers a small area of ground. This paper describes the implementation of a bundle adjustment program for 35 mm oblique aerial photography. Image co-ordinates are measured on enlarged prints, with a digitizing tablet driven by Carto MDSD software, and are then processed with the NLHBUNT program. The measurement system was proved by using vertical standard format photographs of a test block saturated with high quality ground control. Measurements taken with the MDSD system gave acceptable accuracy when compared with a set taken with a Zeiss P3 analytical workstation. A bundle adjustment was then carried out with the MDSD data; the results obtained compared satisfactorily with known ground values. A hand-held 35 mm Pentax LX camera was flown over the test site and three strips of 1:30 000 scale oblique photography were obtained. Following bundle adjustment, the empirical accuracy of derived co-ordinates was about 1.5 m in X, 3 m in Y and 2 m in Z. Factors affecting this accuracy are discussed and further developments of the system are proposed.
 
Russian Space System "KOMETA" equipped with TK-350 and KVR-1000 satellites
Left component of TK-350 stereo-pair with selected Zonguldak testfield (upper side, Black Sea is lying)
Vector plot of errors, thick points are showing GCPs and check points with vectors
Left) Part of the TK-350 digital image with the influences of scratches and film grain. (Right) Situation after the filtering process.
Article
TK-350 stereo-scenes of the Zonguldak testfield in the north-west of Turkey have been analysed. The imagery had a base-to-height ratio of 0-52 and covered an area of 200 km × 300 km, with each pixel representing 10 m on the ground. Control points digitised from 1:25 000 scale topographic maps were used in the test. A bundle orientation was executed using the University of Hanover program BLUH and PCI Geomatica OrthoEngine AE software packages. Tests revealed that TK-350 stereo-images can yield 3D geopositioning to an accuracy of about 10 m in planimetry and 17 m in height. A 40 m resolution digital elevation model (DEM) was generated by the PCI system and compared against a reference DEM, which was derived from digitised contour lines provided by 1:25 000 scale topographic maps. This comparison showed that accuracy depends mainly on the surface structure and the slope of the local terrain. Root mean square errors in height were found to be about 27 and 39 m outside and inside forested areas, respectively. The matched DEM demonstrated a systematic shift against the reference DEM visible as an asymmetric shift in the frequency distribution. This is perhaps caused by the presence of vegetation and buildings. © 2004 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
In many photogrammetric applications, speed is often critical and high accuracy is only a secondary consideration. To use a metric camera in such situations would be quite uneconomical. Non-metric cameras are inexpensive to buy, use and maintain. A top quality 35mm amateur single lens reflex camera might cost £ 1000, an order of magnitude below that of a metric camera. In addition, they are robust, mobile and require a minimum of accessories. In short, they are ideal for rapid, medium to low accuracy work. However, in contrast with a metric camera, a non-metric camera lacks a stable inner orientation, fiducial reference system and standard method of calibration.
 
Article
High-resolution 3D laser scanning in combination with industrial fabrication techniques can be used to make accurate replicas for the heritage sector. Copies may have a reputation for being inferior to the original, but by using digital technology very convincing results can be achieved to a resolution of a fraction of a millimetre. Replicas of caves at Lascaux and Altamira have already been used to help protect the original sites from the risks posed by heavy visitor numbers. Now the same principle is to be applied to the tomb of Seti I in the Valley of the Kings, Egypt. A pilot project was undertaken to produce a full-sized replica of a 16 m 2 section of the burial chamber of the tomb. The aim was to use laser scanning and digital photography to record the tomb at the highest possible resolution, then to output the data as a 3D relief using industrial routing techniques. Finally, the relief was printed in full colour This paper describes the production of the replica including a description of the Seti Scanner, the laser scanning system specifically designed for this project.
 
Article
Ichnology deals with the traces of prehistoric organisms and thus with the study of dinosaur footprints and tracks. This paper reports on a reliable and precise methodology developed to integrate high-resolution close range photogrammetry and range sensors for 3D surveys of dinosaur footprints. The 3D footprint and track models recovered here yield a great deal of accurate morphological and morphometrical information, providing palaeoichnologists with a simpler and cheaper way to document track fossils and the opportunity to formulate new hypotheses about the dynamics of dinosaur locomotion.
 
Article
In this paper an automated methodology is presented (i) to orient a set of close-range images captured with a calibrated camera, and (ii) to extract dense and accurate point clouds starting from the estimated orientation parameters. The whole procedure combines different algorithms and techniques in order to obtain accurate 3D reconstructions in an automatic way. The exterior orientation parameters are estimated using a photogrammetric bundle adjustment with the image correspondences detected using area- and feature-based matching algorithms. Surface measurements are then performed using advanced multi-image matching techniques based on multiple image primitives. To demonstrate the reliability, precision and robustness of the procedure, several tests on different kinds of free-form objects are illustrated and discussed in the paper. Three-dimensional comparisons with range-based data are also carried out.
 
Article
The Institute of Geodesy and Photogrammetry (IGP) at ETH Zurich is participating in the Cartosat-1 evaluation programme, a common initiative of ISRO (India) and ISPRS. Within this programme various test sites with reference data have been established and Cartosat-1 images have been acquired over these sites. Here, investigations at the Rome (Italy) and Maussane-les-Alpilles (France) test sites are reported. First, radiometric problems encountered with the images and pre-processing for their improvement are reported. Examples are shown, together with pre-processing methods that can be employed in order to improve image quality, aimed especially at automatic generation of a digital surface model (DSM) with fewer blunders and more matched points. Then, georeferencing is discussed and the 3D point measurement accuracy that can be achieved is introduced, as well as problems encountered with the rational polynomial coefficients (RPCs). The georeferencing results were produced using various options regarding image pre-processing, the mathematical model used for georeferencing, the number and distribution of ground control points (GCPs) and the GCP image mensuration methods. The best results led to a planimetric and height accuracy (RMSE) of about 1·3 m. Use of an affine transformation after the RPCs, with about six well-distributed GCPs transferred with matching to the second image, is suggested. Finally, the results of automatic DSM generation using the SAT-PP program package developed at the IGP are presented. Various DSMs were generated with 10 m grid spacing. The results were checked visually and were also compared to the reference data provided. In the best case, the accuracy achieved is about 2·7 m without any manual editing, in spite of a 3-year difference between the matching and reference DSMs. Although some aspects regarding image quality and RPC generation could be improved, Cartosat-1 is a useful sensor for mapping and especially for the generation of DSMs. However, owing to its poor absolute geolocation accuracy, Cartosat-1 cannot be used for the generation of a global DSM without GCPs.RésuméL’Institut de Géodésie et de Photogrammétrie (IGP) participe au programme d’évaluation de Cartosat-1, initiative commune de l’ISRO (Inde) et de l’ISPRS. Dans ce programme, plusieurs sites-test avec données de référence ont étéétablis et des images Cartosat-1 acquises sur ces sites. Nous rapportons ici nos recherches sur les sites-test de Rome (Italie) et de Maussane-les-Alpilles (B.-du-R., France). Nous signalons d’abord les problèmes radiométriques rencontrés dans les images et les prétraitements effectués en vue de les améliorer. Nous montrons des exemples et aussi des méthodes de prétraitement pouvant être utilisées pour améliorer la qualité des images, dans le but surtout de générer automatiquement un MNS avec moins d’artefacts et plus de points homologues. Ensuite, nous présentons le géoréférencement et la précision sur la mesure de points 3D qui peut être obtenue ainsi que les problèmes rencontrés avec les Coefficients Polynomiaux Rationnels (RPC). Les résultats du géoréférencement ont été obtenus en variant les options, concernant le prétraitement des images, les modèles mathématiques du géoréférencement, le nombre et la distribution des points d’appui terrain (GCP) et les méthodes de mesure des GCP dans l’image. Les meilleurs résultats ont conduit à des précisions planimétrique et altimétrique d’environ 1,3m (emq). Nous suggérons l’utilisation d’une transformation affine après les RPC, avec appariement d’environ six GCP correctement répartis dans le couple. Finalement, nous présentons les résultats de la génération automatique de MNS en utilisant notre propre suite logicielle SAT-PP. Plusieurs MNS ont été générés avec un échantillonnage spatial de 10m. Les résultats ont été vérifiés visuellement et ont été aussi comparés aux données de référence fournies. Dans le meilleur des cas, la précision obtenue fut d’environ 2,7m sans aucune correction manuelle, malgré une différence de 3 ans entre le MNS obtenu par corrélation et celui de référence. Même si certains aspects concernant la qualité des images et la génération de RPC pourraient être améliorés, Cartosat-1 est un capteur pertinent pour la cartographie, particulièrement pour la génération de MNS. Néanmoins, en raison de sa faible précision de géolocalisation absolue, Cartosat-1 ne peut être utilisé pour la génération d’un MNS global sans GCP.ZusammenfassungDas Cartosat-1 Evaluierungsprogramm ist eine gemeinsame Initiative von ISRO (Indien) und der ISPRS, an dem auch das Institut für Geodsie und Photogrammetrie (IGP) beteiligt ist. Innerhalb dieses Programms wurden verschiedene Testgebiete mit zugehörigen Referenzdaten angelegt. Es stehen für jedes Testfeld Cartosat-1 Bilder zur Verfügung. Wir berichten hier über unsere Untersuchungen in den zwei Testgebieten Rom (Italien) und Maussane-les-Alpilles (Frankreich). Wir behandeln zunchst radiometrische Probleme der Bilder und der Vorverarbeitung. Dann zeigen wir Beispiele und Methoden zur Vorprozessierung zur Verbesserung der Bildqualitt insbesondere mit Hinblick auf die Vermeidung von groben Fehlern bei der DOM Generierung und einer Erhöhung der in den Bildern zugeordneten Punkte. Danach werden wir die Georeferenzierung und die erreichbare 3D Punktmessgenauigkeit behandeln, sowie Probleme im Zusammenhang mit den gegebenen Rational Polynomial Coefficients (RPCs). Die Ergebnisse der Georeferenzierung werden unter Berücksichtigung von verschiedenen Vorgehensweisen bei der Bildprozessierung, dem mathematischen Model für die Georeferenzierung, der Anzahl und Verteilung von Passpunkten und der eingesetzten Bildmessmethoden diskutiert. Das beste Ergebnis liefert eine Lage- und Höhengenauigkeit (RMSE) von ca. 1·3 m. Dabei zeigte sich die Verwendung einer Affintransformation nach der Anwendung der RPCs mit ca. 6 gut verteilten Passpunkten, übertragen in das zweite Bild mit einer automatischer Bildzuordnung, als sehr geeignet. Zum Schluss prsentieren wir die Resultate der automatischen DOM Generierung unter Verwendung unseres Softwarepaketes SAT-PP. Wir haben verschiedene DOMs mit einer Rastergrösse von 10 m generiert. Die Ergebnisse werden zunchst visuell überprüft und danach auch mit den gegebenen Referenzdaten numerisch verglichen. Zwischen der Aufnahme der Bilder und der Erstellung der Referenzdaten liegt zwar ein Zeitraum von 3 Jahren, jedoch wird im besten Fall eine Genauigkeit von 2·7 m ohne manuelle Editierung erreicht. Obwohl einige Aspekte hinsichtlich der Bildqualitt und der Generierung der gegebenen RPCs noch verbessert werden könnten, ist Cartosat-1 ein geeigneter Sensor für den Einsatz zur Kartierung und besonders für die Generierung von DOMs. Aufgrund seiner schlechten Absolutgenauigkeit für die Georeferenzierung kann Cartosat-1 jedoch nicht für die Generierung eines globalen DOMs ohne Passpunkte eingesetzt werden.ResumenEl Institute of Geodesy and Photogrammetry (IGP) participa en el programa de evaluación de Cartosat-1, una iniciativa común de ISRO (India) y de ISPRS. En dicho programa se han definido varias zonas de estudio con datos de referencia y se han obtenido imágenes de Cartosat-1 de estas áreas. En este artículo informamos sobre las investigaciones realizadas en las áreas de Roma (Italia) y Maussane-les-Alpilles (Francia). En primer lugar se identifican problemas radiométricos de las imágenes y se describe el preprocesado necesario para resolverlos. Además, se muestran ejemplos y métodos de preprocesado para mejorar la calidad de las imagenes con el objetivo específico de calcular automáticamente un modelo digital de superficie (MDS) con menos errores groseros y más puntos homólogos. A continuación se describe la georreferenciación y la exactitud que se puede conseguir en la determinación de puntos tridimensionales, así como los problemas relativos a los coeficientes polinómicos racionales (CPR). La georreferenciación se realizó aplicando varias estrategias en el preprocesado de las imagenes, el modelo matemático de georreferenciación, el número y distribución de los puntos de apoyo terrestres y los métodos de medida de esos puntos en la imagen. Los mejores resultados proporcionaron una exactitud RMSE planimétrica y altimétrica aproximada de 1,3 m. Se sugiere aplicar una transformación afín después de los CPR, con unos seis puntos bien distribuidos de apoyo terrestres transferidos mediante correlación a la segunda imagen. Finalmente se presentan los resultados del cálculo automàtico de un modelo digital de superficie (MDS) usando nuestro propio programa SAT-PP. Se calcularon varios MDS con una resolución espacial de 10 m. Los resultados se validaron visualmente y también se compararon con los datos de referencia disponibles. En el mejor de los casos, la exactitud obtenida es aproximadamente de 2,7 m sin edición manual alguna, incluso con una diferencia de tres años respecto el MDS de referencia. Aunque se podrían mejorar algunos aspectos relativos a la calidad de la imagen y el cálculo de los CPR, Cartosat-1 es un sensor muy útil para cartografía y especialmente para el cálculo de MDS. Sin embargo dada la pobre exactitud absoluta de georreferenciación, Cartosat-1 no se puede utilizar para el cálculo de un MDS global sin puntos de apoyo terrestres.
 
Article
Photogrammetry is a non-contact, high-accuracy, practical and cost-effective technique for a large number of medical applications. Lately, three-dimensional (3D) laser scanning and digital imaging technology have raised the importance of digital photogrammetry technology to a new height in craniofacial mapping. Under the support of the Eighth Malaysian Development Plan, the Ministry of Science, Technology and the Environment (MOSTE) Malaysia allocated a grant to establish procedures for the development of a national craniofacial spatial database to assist the medical profession to provide better health services to the public. To populate the database with normal and abnormal (malformation, diseased and trauma and burn victims) craniofacial information, it is necessary to evaluate the technology needed to capture the essential data of craniofacial features. The paper provides a discussion on the basic features of the spatial data and the data capture techniques. Both are needed for the establishment of a national spatial craniofacial database. The discussion includes a brief review of the current status of two selected high-accuracy craniofacial spatial data capture techniques, namely, digital photogrammetry and 3D laser scanning. The paper highlights a system which has been developed for a Malaysian craniofacial mapping project. Laboratory tests with mannequins showed that the photogrammetric and 3D laser scanning system could achieve an accuracy exceeding the design specification of +/- 0(.)7 mm (one standard deviation) for all the measured craniofacial distances. However tests with two living subjects showed that the accuracy was in the order of +/- 1(.)2 mm because of facial movement during data capture.
 
Article
Buddhist stone inscriptions of the 8th to 12th centuries ad are important cultural assets of China that need to be documented, analysed and interpreted archaeologically, art-historically and linguistically. On the one hand, such Buddhist stone inscriptions have to be conserved for future generations, but on the other hand, further possibilities for analysing the data could be achieved if the inscriptions were made accessible to a wider community, for instance, for understanding of the historical growth of Buddhism in China. In this paper, innovative techniques for the documentation of stone inscriptions located in the province of Sichuan, in the south-west of China, are demonstrated. The tasks to be performed include capturing the stone inscriptions by using high precision measuring techniques to generate copies of the original inscriptions, together with processing of the data enabling improvement in the legibility of characters and thus aiding the interpretation of the inscriptions. The concept and features of image processing as applied to the captured inscriptions are outlined. In order to present the outcome to as many people as possible and to allow individual interpretations of the results of the stone inscription reconstruction, their current interpretation and additional 2D/3D maps are published within an interactive web platform. © 2011 The Authors. The Photogrammetric Record © 2011 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Patch definition in least squares matching measurement (left). Triplet of images where patches are assumed to correspond to planar object surfaces and the assumption is not valid (right).
Photogrammetry Fig. 1. Three-dimensional acquisition systems for object measurement using non-contact methods based on light waves.
Article
In this paper the main problems and the available solutions are addressed for the generation of 3D models from terrestrial images. Close range photogrammetry has dealt for many years with manual or automatic image measurements for precise 3D modelling. Nowadays 3D scanners are also becoming a standard source for input data in many application areas, but image-based modelling still remains the most complete, economical, portable, flexible and widely used approach. In this paper the full pipeline is presented for 3D modelling from terrestrial image data, considering the different approaches and analysing all the steps involved. © 2006 The Authors. Journal Compilation 2006 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
The extraction of object features from massive unstructured point clouds with different local densities, especially in the presence of random noisy points, is not a trivial task even if that feature is a planar surface. Segmentation is the most important step in the feature extraction process. In practice, most segmentation approaches use geometrical information to segment the 3D point cloud. The features generally include the position of each point (X, Y and Z), locally estimated surface normals and residuals of best fitting surfaces; however, these features could be affected by noisy points and in consequence directly affect the segmentation results. Therefore, massive unstructured and noisy point clouds also lead to bad segmentation (over-segmentation, under-segmentation or no segmentation). While the RANSAC (random sample consensus) algorithm is effective in the presence of noise and outliers, it has two significant disadvantages, namely, its efficiency and the fact that the plane detected by RANSAC may not necessarily belong to the same object surface; that is, spurious surfaces may appear, especially in the case of parallel-gradual planar surfaces such as stairs. The innovative idea proposed in this paper is a modi. cation for the RANSAC algorithm called Seq-NV-RANSAC. This algorithm checks the normal vector (NV) between the existing point clouds and the hypothesised RANSAC plane, which is created by three random points, under an intuitive threshold value. After extracting the first plane, this process is repeated sequentially (Seq) and automatically, until no planar surfaces can be extracted from the remaining points under the existing threshold value. This prevents the extraction of spurious surfaces, brings an improvement in quality to the computed attributes and increases the degree of automation of surface extraction. Thus the best fit is achieved for the real existing surfaces.
 
Article
The purpose of this work is to present the main features of a structured light system and some experimental results. The system, named SingleShot3DSL, is based on a single off-the-shelf digital camera and a pattern projector. The mathematical model for 3D reconstruction is based on the collinearity equations. A pattern codification strategy was developed to allow fully automatic pattern recognition. A calibration methodology enables the determination of the direction vector of each pattern and the coordinates of the perspective centre of the pattern projector. The calibration processes are carried out with the acquisition of several images of a plane taken from different distances and orientations. Several processes were combined to provide a reliable solution for pattern location. In order to assess the accuracy and potential of the methodology a prototype was built, integrating a pattern projector and a digital camera in a single mount. Experiments using reconstructed surfaces with real data indicated that a relative accuracy of 0 center dot 2 mm in depth could be achieved.
 
Article
Three-dimensional (3D) reconstruction and texture mapping of buildings or other man-made objects are key aspects for 3D city landscapes. An effective coarse-to-fine approach for 3D building model generation and texture mapping based on digital photogrammetric techniques is proposed. Three video image sequences, two oblique views of building walls and one vertical view of building roofs, acquired by a digital video camera mounted on a helicopter are used as input images. Lidar data and a coarse two-dimensional (2D) digital vector map used for car navigation are also used as information sources. Automatic aerial triangulation (AAT) suitable for a high overlap image sequence is used to give initial values of camera parameters of each image. To obtain accurate image lines, the correspondence between outlines of the building and their line features in the image sequences is determined with a coarse-to-fine strategy. A hybrid point/line bundle adjustment is used to ensure the stability and accuracy of reconstruction. Reconstructed buildings with fine textures superimposed on a digital elevation model (DEM) and ortho-image are realistically visualised. Experimental results show that the proposed approach of 3D city model generation has a promising future in many applications.
 
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The paper deals with the determination of the metric quality of a 409634096 pixel high resolution digital camera back achieved from testfield measurements.
 
Article
After a brief explanation of the role of the Directorate of Military Survey, the paper describes the production of part of a new series of 1:100 000 scale maps of Oman by soldiers of 42 Survey Engineer Group. Starting with the design and observation of the field survey control network, continuing with aerial triangulation and plotting, followed by compilation and all stages of production from drawing to printing of the maps, the project exercised the skills of survey technician soldiers to a high degree. The paper elaborates on the unusual problems caused by the barren nature of the terrain and describes the use of advanced technology during the latter part of the project.
 
Article
The camera is a further development of an existing type with greatly improved photogrammetric performance so that the photography can be used with first-order plotting machines. A new lens provides minimal distortion, high resolution and greatly improved marginal illumination. An entirely new shutter provides high speeds and efficiency. Laboratory results and preliminary survey trials indicate image quality and location standards of the same order as established existing cameras.Résuméľappareil est un développément ulterieur ď un type existant, ď un rendement photogrammétrique grandement amélioré, de sorte que la photographie peut être utilisée avec des restituteurs de premier ordre. Un nouvel objectif fournit une faible déformation, une image trés nette et une bien meilleure illumination des bords. Un obturateur entiérement nouveau donne des temps de pose trés courts et un bon rendement. Les résultats en laboratoire et les essais préliminaires pratiques indiquent que la qualité de ľimage et la précision géometrique sont au moins équivalentes à celles des meilleurs appareils actuellement en usage.
 
Article
This paper describes three mathematical modelling methods for high-resolution declassified CORONA KH-4B images. Since CORONA images are collected with a panoramic camera, several types of geometric distortions are involved. Two methods use the modified collinearity equations, and the third involves the terrain-dependent rational function model (RFM) which is considered to be a generic sensor model. Comparative analysis of the three mathematical modelling methods is undertaken. The results show that a ± 1.5 pixels level of horizontal and vertical accuracy can be obtained. A digital elevation model (DEM) of a test site is also created. © 2004 The Remote Sensing and Photogrammetry Society and Blackwell Publishing Ltd.
 
Article
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. 1993 Blackwell Publishing and the Remote Sensing and Photogrammetic Society
 
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Fabio Remondino
  • Fondazione Bruno Kessler
Clive Fraser
  • University of Melbourne
Jim H. Chandler
  • Formerly at Loughborough University
Sabry El-Hakim
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Stuart Lane
  • University of Lausanne