SURVEYING FROM AIR PHOTOGRAPHS FIXED BY REMOTE RADAR CONTROL*

Abstract

During the last thirty years, developments in the taking of air photographs (and of mapping from them) have been progressive until, under present day conditions, no programme of topographical mapping for economic development can be satisfactorily undertaken without using them.     

SOME FACTORS IN DETERMINING HEIGHTS FROM AIR PHOTOGRAPHS

Abstract

The graphical methods developed at the War Officeof mapping from strips of vertical photographs are generally widely known. It may be fairly said that they frequently present a reasonably economical method of mapping the planimetry of a country on medium topographical scales when there is a normal third-ordertrigonometrical control, but that so far it has not been possible to provide economically for the accurate depiction of the ground relief. The reason, for this failure is due to the fact that the control required fot contouring is about one fixed height per square inch of map, and the cost of providing this control will normally be of the same order as the cost of mapping by ground methods.     

USE OF SPACE PHOTOGRAPHS IN THE MAKING AND REVISION OF SMALL-SCALE MAPS

A brief review paper focuses on Soviet strategies for the use of space imagery, particularly photographic products (1:2,000,000 to 1:4,200,000 scale) from manned spaceflights, in the revision of small-scale general reference maps. Principles for the interpretation and mapping of basic map elements appearing on space photographs are outlined. Space photographs provide for reduction in time spent in map editing and the more correct analysis of the reliability of information and its generalization. A technology of map revision based on the joint use of original photographs and photomaps, with the transfer of revisions from photomaps to map originals, is proposed. Translated from: Geodeziya i kartografiya, 1986, No. 8, pp. 29-33.     

A Small War,Gallipoli 1915. He Who is Above Sees All: An Early Use of Aerial Photography in Terrain Analysis

Abstract

When Lord Kitchener ordered Sir Ian Hamilton in 1915 to command land operations on Gallipoli he gave him a solitary old One Inch map and denied him any air forces. When Winston Churchill had earlier sent the Royal Navy to break through to the Black Sea, he had ensured that the Royal Naval Division withdrawn from fighting on the Western Front was accompanied by a Naval Air Squadron as its forward reconnaissance element. Ernest Dowson, the Surveyor General of Egypt, appointed to provide local mapping support, soon convinced the Naval pilots of the value of air photography taken systematically to meet his map-making requirements. In September 1915 Dowson wrote a Secret technical report demonstrating for the first time to British Commanders the practicality of mapping from specified aeroplane photographs of the operational area.     

RECONNAISSANCE MAPPING FROM TRIMETROGON AIR PHOTOGRAPHS IN THE ANGLO-EGYPTIAN SUDAN

Abstract

Trimetrogon air surveys have been used extensively in the United States and Canada but seem to have had less favour on this side of the Atlantic in spite of the fact that large areas over here were photographed in this way during the last war. The Sudan is a very large country, but not a rich one; and up to the present it has not been able to undertake its own aerial photography. The gift of a very large number of American trimetrogon photographs covering half the country was therefore very welcome, and it seemed worth our while to see what could be done with them in spite of the known disadvantages of this type of photography for anything but small scale mapping. The methods of planimetric mapping from these photographs developed in the United States were expressly designed to be as simple as possible and to be capable of division into a number of easy tasks which could be performed by any educated person after a short course of training. Nevertheless we felt that they could be simplified a great deal more if the problem was approached from a different angle, particularly in view of the very high standard of flying which was apparent in the photographs covering the Sudan.     

Use of cartographic images by expert and novice field geologists in planning fieldwork routes

Topographic maps and aerial photographs are particularly useful when geoscientists are faced with fieldwork tasks such as selecting paths for observation, establishing sampling schemes, or defining field regions. These types of images are crucial in bedrock geologic mapping, a cognitively complex field-based problem-solving task. Geologic mapping requires the geologist to correctly identify rock types and three-dimensional bedrock structures from often partial or poor-quality outcrop data while navigating through unfamiliar terrain. This paper compares the walked routes of novice to expert geologists working in the field (n = 66) with the results of a route planning and navigation survey of a similar population of geologists (n = 77). Results show clearly that those geologists with previous mapping experience make quick and decisive determinations about field areas from available imagery and maps, regardless of whether they are or not physically present in the field area. Recognition of geologic features enabled experts to form and verbalize a specific plan for travel through a landscape based on those features. Novices were less likely to develop specific travel route plans and were less likely to identify critical landscape cues from aerial photographs.     

A LANDSCAPE-TYPOLOGY REGIONALIZATION OF MONGOLIA BASED ON SPACE IMAGERY

A joint Soviet-Mongolian project of 1978-80 using space imagery for the mapping of Mongolia's natural resources is described. The novelty of using space photographs called for the development of new techniques. The remote sensing approach enabled the investigators to compile within a relatively short time a map of natural territorial complexes of Mongolia, distinguished by a high degree of detail, and to gain a new understanding about many aspects of the Mongolian Physical environment. Translated from: Izvestiya Akademii Nauk SSSR, seriya geograficheskaya, 1984, No. 4, pp. 5-14.     

Three Types of Reconnaissance Mapping

Abstract

This account of exploratory mapping is provided by a surveyor who started his working life as an explorer in areas where existing maps were extremely rough and rudimentary. Although the methods and results it describes will not stand comparison with modern topographical maps compiled from vertical air photographs, this frank and objective appraisal will help the 'chair-borne' cartographer to understand the importance of a thorough evaluation of some material of that type and age, which is still sometimes the best available until the new air surveys replace it.     

GCP collection for corona satellite photographs: Issues and methodology

Use of high-resolution and historic CORONA satellite photographs for mapping and other purposes requires Ground Control Points (GCPs), as ephemeris data and image parameters are not available. However, the alterations in landscape in last 34 years (i.e., since the acquisition of these photographs) prevent identification and collection of large number of GCPs in the field. This paper presents a methodology for collection of GCPs for CORONA photographs. The advantages and limitations of the methodology are discussed. For a study site, situated in Siwaliks and Lower Himalayas, the GCPs were identified in CORONA photographs and their WGS84 coordinates were estimated through a process of datum transformation and georeferencing. Estimated GCP coordinates from the topo sheets and 2D and 3D views of photographs, helped in identifying the GCP locations in field, which were observed using DGPS. Investigations were carried out to relate Differential Global Positioning System (DGPS) accuracy with base line length and time of observation. Abase line of 350 km and half an hour observation were found appropriate to yield accuracy in GCP collection by DGPS method, which conforms to CORONA resolution of 3 m.     

A PROJECTION METHOD OF MAPPING FROM AIR PHOTOGRAPHS

Abstract

An instrument was previously described in the Transactions of the Royal Society of S. Africa for the setting of pairs of photographs, taken from air stations, in correspondence; that is, in the same relative positions that the camera occupied in space at the moments of exposure. The principle of the instrument may be recalled.     

FMC cameras,high resolution films and very large scale mapping

Abstract

Very large scale mapping (1/250) was experimented on the basis of FMC camera, high resolution film and total station surveying.

The future attractive combination of precision photogrammetry and personal computer assisted terrestrial surveying was investigated from the point of view of accuracy, time effectiveness and total procedures control.     

AERIAL CAMERA CALIBRATION

Abstract

Accidents will happen and the surveyor is therefore sometimes required to do the best he can with photographs taken with an uncalibrated camera which is not available for subsequent calibration. This note outlines a method by which an approximate principal distance can be obtained for high oblique air photographs from points appearing in the photographs.     

THE RECTIFICATION OF AIR PHOTOGRAPHS

Abstract

The application of the formulae for the rectification of air photographs, with or without change of scale, becomes greatly simplified when the tilt of the photographs is small. Usually this tilt does not exceed 2°, and the rectification may take place in a comparatively simple form of camera and with hardly any computations, since, as will be shown, variations of the camera settings are then accurately linear in relation to the tilt. It will also be shown that in the result the errors due to small differences in the focal length of the air camera lenses, to distortion from the pressure plate, and to average shrinkage of the film, can be automatically eliminated.     

AIR SURVEY: THE RAND METHOD OF HEIGHTING FROM NEAR VERTICAL PHOTOGRAPHS

Abstract

The method outlined below is a simple and rapid method, requiring no expensive equipment, of obtaining true heights from pairs of near vertical air photographs with a minimum of ground control. It is a direct application of the Fourcade theorem and, as it was finally developed at the University of the Witwatersrand in 1948-49, it has been given the name “Rand method” in the hope that this will connect it with Dr. Fourcade's country.     

REMOTE SENSING IN THE MORPHOMETRIC ANALYSIS OF CHANNELS AND FLOODPLAINS

The first of two papers devoted to the analysis and mapping of river channels and floodplains describes Soviet work in the photogrammetric and cartometric analysis of floodplain morphology based on remote sensing imagery. The emphasis of the present paper is on the creation of digital terrain models for the automated measurement and mapping of floodplain features. Considerable attention is focused upon analysis of indicators of channel and floodplain dynamics (channel deposition, bankside erosion, meanders) appearing on aerial photographs. The results of channel analyses based on aerial photographic and field methods (determinations of channel width, depth, etc.) are compared for a test site. Translated from: Geomorfologiya, 1986, No. 4, pp. 51-57.     

APPLICATIONS OF REMOTE SENSING IN THE STUDY OF THE MOUNTAINOUS TERRAIN OF DAGESTAN

The authors explore a wide range of applications of remote sensing methods in the study of natural hazards posed by exogenous geomorphologic processes in areas of predominantly calcareous and shale-based rock in mountainous portions of Dagestan. Space imagery, air photographs, and ground truth established from field observations provides the basis for the mapping of environmental conditions with an emphasis on the extent to which mass movements and other exogenous geomorphologic processes pose natural hazards to human residence and economic activity. Translated by Elliott B. Urdang, Providence, RI 02906 from: Geomorfologiya, 1993, No. 4, pp. 26-35.     

AN ANALYTICAL METHOD FOR IDENTIFYING STRUCTURE LINES IN TOPOGRAPHY

Methods for the quantitative analysis of topographic data in the identification of structure lines are presented. Use of the techniques in the relief mapping of a study plot, and comparison of the results with those obtained through visual methods of photo analysis, showed that the new approach identified all structure lines readily visible on aerial photographs in addition to several that were not. The methods are most promising for situations in which the process of data collection does not favor the visual positioning of structure lines. Translated from: Geodeziya, kartografiya, i aerofotos'yemka, No. 39, 1984, pp. 135-140.     

Principle, software and experiment of GPS-supported aerotriangulation

1 IntroductionAs is now well known, the high accurate point de-termination with airborne remOe sensing data hasalways ben one of the most fundaxnental prObletns..in aerial photOgrammtry. According to the princi-ple of the geOmtry reversal in photOgramrntry,the interior and exterior orientation elements ofaerial phOtOgraphs must first be known in order toreconstnJct the measuring stereo geometric medels.For the past 60 years, however, the interior orienta-tion parameters of carnera were main…