Oblique Aerial Photographs Research Articles

The 1931 Shippee-Johnson Aerial Photography Expedition to Peru

THE development and use of aerial photography were primarily initiated during and immediately after World War I. A systematic technology was rapidly devised that shifted from military applications to mapping, geographical surveys, planning, and archaeology. In the United States, the American Geographical Society played a major role in the shift by funding projects and publishing their results in its publications (Wright 1952, 338-342). One of these projects was the Shippee-Johnson Expedition to in 1931. Some of the first published aerial photographs, which were views of Paris, San Diego, Miami, and Tientsin, appeared in a 1917 Geographical Review article (Woodhouse 1917). Technical articles were published in 1920 (Lee 1920; Moffit 1920), and a regional study of Morocco was based on aerial photographs (Blache 1921). Five volumes in the Special Publications series were devoted to aerial photography, or airplane photography, as it was initially called. first volume was The Face of the Earth as Seen from the Air (Lee 1922), which utilized photographs taken by the U.S. Army and Navy. It was followed by Peru from the Air (Johnson 1930), Northernmost Labrador (Forbes 1938), Focus on Africa (Light 1941), and The Face of South America (Rich 1942). All these books were well illustrated, with generally excellent vertical and oblique aerial photographs. volume on led directly to the Shippee-Johnson Aerial Photography Expedition in 1931, the results of which have been of enduring importance. expedition, endorsed by the American Geographical Society, received international attention at the time because of the high quality of the photography and the spectacular landscapes, prehistoric ruins, and other features it revealed. expedition was the first systematic attempt to use aerial photography to discover, locate, and describe prehistoric ruins and agricultural features in South America; Charles Lindbergh had taken photographs from the air of pueblo ruins in New Mexico and of Mayan causeways and cities in Yucatan in 1929 (Ricketson and Kidder 1930; Deuel 1969, 187-213). Also, a study of the ruins of Chan Chan in had made some use of aerial photography (Holstein 1927). Particularly impressive is the resolution of well-preserved overlapping vertical photographs taken by Shippee and Johnson of the Colca Valley in the Andes of southern Peru. Shippee-Johnson photographs continue to be used and published by geographers, archaeologists, and other scholars. Because of the current interest, this article describes the expedition, the resultant photography, and its whereabouts. There are several sources. Shippee (1932a, 1932b, 1933, 1934) published four articles about the expedition. Information on the progress of the expedition appeared in the West Coast Leader (1931-1932). Brief descriptions are found in Deuel (1969, 225-234), Jackson (1983, 164-171), and Fundacion Colca (1989). Information on the surviving photography was obtained from Robert Shippee, Loren McIntrye, the American Museum of Natural History, and the Servicio Aerofotografico Nacional in Lima, which Johnson founded. A file in the archives of the American Geographical Society contains correspondence about the 1931 expedition. Most of the items in the file are dated 1930 or 1931, including letters between Isaiah Bowman or Raye Platt and either Johnson or Shippee. U.S. ambassador in Lima initially was contacted about logistics and permits and later about the promised but delayed submission of prints of 6,000 photographs to the Peruvian Ministry of Marine and Aviation. society, as endorser of the expedition, acted as an intermediary in what were sensitive issues. Also of interest, Bowman corresponded with Alfred Kroeber, Julio Tello, and other archaeologists regarding whether Shippee and Johnson were the first to discover the Great Wall of Peru. JOHNSON'S PHOTOGRAPHY 1928-1929 precedent of the 1931 expedition was the aerial photography of U. …

Surveying a Waste Site with 35-mm Oblique Aerial Photography: Monoplotting with a Digitizing Tablet

Hand-held, small-format (35-mm) aerial photography can provide reliable measurements for geographic information system (GIS) data collection. This article presents a waste-site investigation in which a digital monoplotter was used to capture measurements from enlarged 35-mm oblique photography. Smallformat overlapping photography was used to create a digital elevation model, which supplied elevation data for digital monoplotting. Point locations for installing monitoring instruments were plotted on a single 35-mm photograph (1:5,187 scale) and subsequently were located in the field with 43-cm accuracy. Results suggest the low-cost method is suited for waste-site investigations and GIS data capture.

Estimation of Horizontal Diffusion from Oblique Aerial Photographs of Smoke Clouds

Abstract A photogrammetric method is described for obtaining estimates of the horizontal diffusion parameter σy from oblique aerial photographs of smoke clouds. The method requires three reference markers on the ground to determine the geometry in each oblique photograph. Besides the distances between these markers, the only other independent information required for the method is the focal length of the camera lens and the enlargement factor of the photographs. The method is particularly useful for estimating σy at small sampling times, including relative diffusion. Additionally, it provides high spatial resolution in the downwind and crosswind directions and places no restrictions on the wind directions for which diffusion data can be collected.

Rockslides on the Terminus of “Jökulsárgilsjökull”, Southern Iceland

On 10 November 1976, a 1.5 km × 0.5 km rockslide deposit on the surface of an unnamed outlet glacier of Mýrdalsjökull ice cap, southern Iceland, was observed from an aircraft. Deposits from two different rockslides, including the larger one observed on 10 November 1976, were visible on a 10 September 1978 aerial photograph of the unnamed outlet glacier. An analysis of vertical and oblique aerial photographs, Landsat images, and seismological records was used to establish the time of occurrence of the larger rockslide to a 30-day period between 9 September 1972 and 9 October 1972. The trigger mechanisms for the rockslide activity appear to have been heavy precipitation prior to the event and the decrease of buttressing mass at the base of the valley wall resulting from recession of the glacier (decrease in width and thickness). The recession led to instability of highly altered hyaloclastite bedrock, talus, and morainal materials on an oversteepened slope. An earthquake as a trigger mechanism was considered to be unlikely from a thorough review of seismic records. Measurements of the downglacier movement of the larger rockslide deposit give an average speed of the glacier as 30±3 m a-1 between September/October 1972 and 10 September 1978. From measurements of aerial photographs taken on 10 September 1978 and 4 September 1984, the average speed of the glacier increased to 45 m a-1 during this 6-year interval. Although the terminus of the unnamed outlet glacier had not yet begun to advance in 1986, it had undergone thickening since 1978.

Rockslides on the Terminus of "Jokulsargilsjokull", Southern Iceland

On 10 November 1976, a 1.5 km × 0.5 km rockslide deposit on the surface of an unnamed outlet glacier of Mýrdalsjokull ice cap, southern Iceland, was observed from an aircraft. Deposits from two different rockslides, including the larger one observed on 10 November 1976, were visible on a 10 September 1978 aerial photograph of the unnamed outlet glacier. An analysis of vertical and oblique aerial photographs, Landsat images, and seismological records was used to establish the time of occurrence of the larger rockslide to a 30-day period between 9 September 1972 and 9 October 1972. The trigger mechanisms for the rockslide activity appear to have been heavy precipitation prior to the event and the decrease of buttressing mass at the base of the valley wall resulting from recession of the glacier (decrease in width and thickness). The recession led to instability of highly altered hyaloclastite bedrock, talus, and morainal materials on an oversteepened slope. An earthquake as a trigger mechanism was c...

AN ANALYTICAL-PHOTOGRAMMETRIC SYSTEM FOR THE QUANTITATIVE STUDY OF VOLCANIC FEATURES

A photogrammetric method is described for analyzing the geometric and dynamic parameters of volcanic eruptions, which makes it possible to estimate the scale of developing eruptions and promotes a more complete understanding of their mechanics. Digital models are constructed for different periods of volcanic activity on the basis of near-vertical and oblique aerial photographs. The method is illustrated with observations from several volcanoes on the Kamchatka Peninsula, taken since 1977 with a frequency of 12–15 times per year. Translated by Edward Torrey, Alexandria, VA 22308 from: Geodeziya i kartografiya, 1989, No. 1, pp. 22–29.

Analytical photogrammetry: a method for monitoring slope instability

Abstract Developments in analytical photogrammetry provide the engineering geologist and geomorphologist with a quantitative technique capable of monitoring slope instability from ground or oblique aerial photographs. This paper outlines ‘analytical’ photogrammetry and its applications to the study of slope instability. Procedures and developments in data processing are described that enable both a morphogenetic analysis of slope form and the derivation of displacement vectors for monitoring unstable slopes. The methods are illustrated by research work carried out by the authors in Nepal and southern England.

A PHOTOGRAMMETRIC SYSTEM FOR ARCHAEOLOGICAL MAPPING USING OBLIQUE NON‐METRIC PHOTOGRAPHY

AbstractThe Air Photographs Unit of the Royal Commission on the Historical Monuments of England (RCHM) has taken a large collection of oblique aerial photographs, using a non‐metric camera, of archaeological evidence. Techniques are described which use this photography in conjunction with a Kern DSR1 analytical plotter to produce maps. Some results from using the techniques are given.

THE EXTRACTION OF POSITIONAL DATA FROM HISTORICAL PHOTOGRAPHS AND THEIR APPLICATION TO GEOMORPHOLOGY

AbstractA technique which enables spatial data to be obtained from historical photography is outlined. The method is applied to a 40 year sequence of oblique aerial photography of the Black Ven landslide in Dorset, England. Some of the possible data processing options are discussed and illustrated by some preliminary results produced from the Dorset landslide.

Geological photogrammetry using oblique aerial photographs

Large areas in Greenland are covered by oblique aerial photographs, taken with 23 x 23 cm2 photogrammetric cameras of the type 'EagIe' between 1948 and 1953. Though almost all of Greenland is now covered by modem vertical photographs, the oblique photographs still represent a valuable alternative source of geological information because of the perspective at right angles to the mountain side. So far, geologists have only been able to use the oblique photographs for visual interpretation. New photogrammetric instruments like the Kem DSR U/GPl Analyticai Plotter at the Institute of Surveying and Photogrammetry,the Teehnieal University of Denmark, make it possibie for geologists to map precisely from oblique photographs. This report deseribes an experiment where such photographs have been used for mapping of steep mountain sides for the production of geological maps, cross-seetions and perspective views. Earlier results are reported by Dueholm & Garde (1986) and Heinesen (1987).

Stereo oblique aerial photography and analysis as a technique in the planning/design of site investigations within areas of glacial till

Stereo oblique aerial photography and analysis as a technique in the planning/design of site investigations within areas of glacial till

Cliff stability evaluation using geomorphological maps based on oblique aerial photographs

Abstract Geomorphological mapping is a well established tool in terrain evaluation. A case record is presented in which high-oblique aerial photography from a light aircraft has been used for basic mapping of a 3 km length of coastline with the purpose of assessing relative landslide hazard. The cliffs at Budleigh Salterton, East Devon, are formed in a succession of Permo-Triassic mudstone, conglomerate and sandstone which dip gently eastwards along the coast. The coastline is divided into five units based on changes in the stratigraphic succession exposed in the cliff face; each unit correlating with distinctive geomorphological features and cliff profiles. Groundwater discharges, wave attack and weathering ensure that there is continuing geomorphological activity. This necessitates frequent updating of local hazard assessment. Overlapping aerial photographs of the cliff face have been taken at intervals during the past six years. With limited ground inspection these photographs provide adequate data for basic geomorphological mapping of the principal forms represented in the cliff. Successive series of photographs are used to follow the development of individual features and to identify the hazards present in each section of the cliff. Data from early Ordnance Survey maps, old photographs and personal reminiscences extend parts of the history of the coast back into the last century. The positions of landslides are controlled largely by geological and hydrological factors whereas the timing of events is often a function of external environmental triggering mechanisms such as weather, tide or waves. A classification of the relative hazard of cliff-top instability has been used to map hazard zones for the coastline. Together with the system of photographic data acquisition advocated, this provides a rapid and economic method to assist planning authorities in determining development strategy.

TOPOGRAPHIC SHADING AND GEOGRAPHICAL PATTERNS OF DIRECT SOLAR RADIATION IN MOUNTAINOUS REGIONS∗

Topographic shading curtails the period and complicates the geographic patterns of insolation in mountainous areas. Maps derived from oblique aerial photographs of shadow lines cast by the irregular, mountainous east horizon in Provo, Utah are used as a case study to illustrate an alternative to existing techniques of solar radiation data collection. For study areas of several hundred square kilometers, this method may be superior in resolution and at the same time more error free and economically feasible than other methods. Measurement of solar inputs received at sample stations scattered through the mapped area show that the phenomenon of topographically delayed sunrise has a distinct effect on daily totals of radiation in the manner suggested by the maps.

The Use of Oblique Aerial Photography to Investigate the Extent and Sequence of Landslipping at Stag Hill, Guildford, Surrey

Abstract The University of Surrey is situated on the northern slopes of Stag Hill, below Guildford Cathedral, which occupies the summit. During the investigation for the design of the University, it became apparent that the site was underlain by a large landslip, 500 m wide from east to west and extending 160 m from rear scarp to toe. Considerable effort was made to establish its geometry and extent (Skempton & Petley (1967), and Morgenstern & Tchalenko (1967)). In recent years it was realised that because the construction of the Cathedral extended over a long period of time, the likelihood of Stag Hill being covered by oblique aerial photography would be high. Some forty oblique aerial photographs, spanning the period 1949 to 1982, were collected and analysed together with vertical aerial photographs and topographic maps. Although the landslip is visible on vertical aerial photographs, individual elements are not easily identified. Using oblique photography, in particular that in which recognition of subdued topography has been enhanced by low sun angles, up to six phases of landslipping were identified. This paper uses this example to demonstrate the usefulness of aerial photography in site investigation and in particular the value of oblique photography, a topic which receives little attention in BS 5930:1981 considering how cost effective this tool can be.

Aerial Photography for the Detection of Leachate Migration from Landfills

Abstract Aerial photography of the perimeters of two landfilled areas in British Columbia was acquired in colour and infrared emulsions. The photography was examined for evidence of leakage, or flooding of the leachate collection ditches surrounding the landfill and vegetation stress caused by the landfilling. At. one site the photography was acquired using a miniature experimental remotely piloted aircraft. This aircraft carries two gimbal-mounted 35 mm cameras which allow simultaneous vertical photography using two different film emulsions, different lenses, and/or filter combinations. At the second landfill site, oblique aerial photography was acquired from a Cessna 172 aircraft. Preliminary interpretation of the photography was followed by visits to locations where possible problems associated with leachate containment were apparent. The results indicated several locations where leachate was not fully contained by the ditch network and some areas of vegetation stress. Further studies at the second site confirmed that improved containment was effective in preventing further environmental damage.

Coastal erosion and accretion, Stanwell Park Beach, N.S.W., 1890–1980

Summary A direct linear transformation method was used to locate the position of high tide run‐up from oblique and vertical aerial photographs of Stanwell Park beach, N.S.W. between 1890–1980 on a plan map accurate to ± 2.5 m. Results indicate minor net erosion of less than 5 m over these ninety years. Accretion was dominant during the 1930s and ‘40s, while the effects of occasional erosional events increased after 1948. Even though Stanwell Park beach would be expected to undergo changes similar to those reported from other adjacent beaches, the record shows significant discrepancies. The data indicate that profiling of part of a beach may not be representative of changes on the beach as a whole.

The National Air Photo Library

La photothèque nationale de l'air compte plus de quatre millions de photographies. On peut admirer des photos de tous les coins du pays, campagne et villes. Depuis la création du service dans les années 1920, on a pris des photographies aériennes verticales, obliques et panoramiques de beaucoup d'endroits.

New Zealand fur seals at the Bounty Islands

Abstract New Zealand fur seals, Arctocephalus forsteri (Lesson, 1828), at the Bounty Islands (47°45'S, 179°03'E) were virtually annihilated by commercial sealing in the period 1808–1890. Legal protection and the cessation of sealing in 1891 were followed by a slow increase in numbers. Aerial photography is a practical method for monitoring fur seal numbers at the Bounty Islands, where the animals show up clearly on the smooth granite substrate. Low‐level oblique aerial photographs taken between May 1974 and December 1980 have been used to determine the present distribution of seal colonies and estimate the numbers ashore. The number of seals (excluding new‐born pups) ashore on 29 December 1980 was estimated as 6700, and the number of pups as 3280, from sample counts of 3050 and 477 respectively. Calculations based on estimated pup production, and published figures on immature mortality, sex ratio, and pregnancy rate from other fur seal populations, suggest that the total population of the Bounty Islands i...

A PROCESS-RESPONSE MODEL FOR HURRICANE WASHOVERS

The passage of Hurricane Allen over Padre Island in August 1980 presented an excellent opportunity to study the effects and controls of coastal morphology on hurricane deposits. In the Caribbean Sea, Hurricane Allen achieved a central pressure of 899 mb, making it the second strongest Atlantic hurricane ever recorded. Once in the Gulf of Mexico, the storm approached the Texas coast from the east-southeast, building a significant storm surge. Near Brownsville, the storm stalled, spending much of its energy offshore before making landfall early on August 10th near Brazos Santiago Pass at the southern tip of Padre Island. Surge gauges show that peak recorded storm tides of about 3 m occurred at Port Mansfield, some 35 km north of landfall. Analysis of tide data indicates a time lag of some 14 hours on the rising storm tide between the Gulf and south Laguna Madre. This is due both to the limited tidal exchange across Padre Island and to set-down in the lagoon due to southward-directed cyclonic winds. By contrast, measurements taken in Corpus Christi Bay, some 180 km north of landfall, show that at that point Gulf and bay tides were in phase. The cross-barrier water level differential at South Padre Island (up to 1.5 m) greatly facilitated hurricane breaching of the island. Oblique and vertical aerial photography show that Padre Island was breached in many places, with about 40 major hurricane channels still open several days after the storm. Surge heights were sufficient to inundate all of South Padre Island except for isolated "dune islands" resulting in broad and often coalescing washover deposits. The more continuous dune ridge on North Padre Island resulted in smaller, discrete washovers. Intensity, distribution, and morphology of washovers are functions of storm tide elevation, its phase relationships, island topography, and lagoonal water depth. The relationship is complex, yet precise enough to permit prediction of the island's response to the impact of a given storm.

Image Perspective Transformationsâ€â€?Urban Scenes

This paper discusses a technique for converting digitized oblique low-altitude aerial photography to gray level imagery as seen from other viewing perspectives. The technique makes use of one- and two-camera perspective transformations. Inputs to these transformations are camera model information and a stick figure representation of the scene. The required camera model information is extracted from the imagery in conjunction with limited map data. Three-dimensional stick figure models are constructed interactively using the camera model and the digitized photograph. The perspective transformations are applied to the gray level image, pixel-by-pixel, and hidden surface corrections are performed to produce the new perspective views. The resulting images maintain the noise and resolution qualities of the original digitized imagery.