Remote sensing for resources development and environmental management: Remote sensing for resources development and environmental management

damen, m. c. j.

Bibliographic data

Multivolume work

Persistent identifier:: 856342815

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Year of publication:: 1986

Place of publication:: Rotterdam; Boston

Publisher of the original:: A. A. Balkema

Identifier (digital):: 856342815

Language:: English

Additional Notes:: Volume 1-3 erschienen von 1986-1988

Editor:: Damen, M. C. J.

Document type:: Multivolume work

Volume

Persistent identifier:: 856662364

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Scope:: VI, Seiten 959-1074

Year of publication:: 2016

Place of publication:: Rotterdam; Boston

Publisher of the original:: A. A. Balkema

Identifier (digital):: 856662364

Signature of the source:: ZS 312(26,7,3)

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Damen, M. C. J.

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: Invited papers

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: Small Format Aerial Photography for analysing urban housing problem (Case study: Bangkok Metropolitan Region). C. Chanond & C. Leekbhai

Document type:: Multivolume work

Structure type:: Chapter

To obtain a new set of photographs very quickly and at a cost low enough to be readily justifiable in the context of such a survey, the use of "Small Format Aerial Photography" (SFAP) was then considered. 3 SMALL FORMAT AERIAL PHOTOGRAPHY AS AN ALTERNATIVE. Small format aerial photography may be defined as a (camera) image format with sides smaller than 12 cm. It includes the 6x6 cm. roll film formats (120,220) and the 70 mm. perforated film format, both having an image size of 55 x 55 mm. and the 35 mm. film format with an image size of 24 x 36 mm. (Hofstee, 1982). It is a low cost technique that uses the same principles as large format aerial photography but without complex and expensive in strumentation and only requires light planes. There has been increasing interest in recent years in the use of supplementary airphotos taken with small format cameras to provide up-to-date informa tion for planning. In 1978, the Bandung Institute of Technology used this technique for an Integrated Approach for Marginal Settlement Improvement. A light single engine Indonesian produced Gelatik aircraft, was used with a Canon 35 mm camera mounted in the open ing otherwise used for spraying equipment. The camera was a normal single lens reflex camera with 50 mm. lens. The flight altitude was 800 meters, negatives were enlarged to 20 and 30 cm size and photocopied for use in a self-help survey. Although exact scale mapping is not possible, the results are more than adequate for the requirements of a mar ginal settlement improvement project. (POERBO and SHUBERT, 1982) Spencer (1978) has experimented with small format aerial photography for map revision using a 70 mm. camera which was mounted outside the open doorway of a Cessna 182 aircraft. Navigation was first based on unaided visual observations. The success of the trials ensured a continuing use of the approach but in order to improve the accuracy of flight line navigation and the comfort of flying, the light aircraft was modified for internal mounting of the camera and fixing point for a drift sight. The camera was a Vinten 70 mm fitted with a lens of 3 in. focal length. It has a format of 56 by 57 mm. and was electrically operated. The magazine had a film capacity approximately 500 frames (100 ft.). Usually, the flying altitude was 10,000 ft. Contact negatives of scale 1:28,000 to 1:40,000 were obtained; 5,100 hectares of plantations were photographed. Curran (1981) of Department of Geography, University of Reading, England, applied the small format, light aircraft photography to study the relationship between green biomass vegetation productivity and bidirectional reflectance. A Cessna 172 and Dehavilland Chipmunk aircraft were used with Cannon 35 mm camera for hand-held aerial photography. Also a Hasselblad 70 mm motor drive camera system that fits over an observation port in the aircraft fuselage was used for vertical photography. In this case the aircraft used was a Piper Aztec, a six-seater, twin engined, low wing aircraft. 4 SFAP OPERATIONAL SURVEY FOR BANGKOK METROPOLITAN REGION Considering the amount of data needed to be col lected from the air photographs, processing time, cost constraints, and the previous successful experi ments of SFAP in a number of small area applications, it was decided that SFAP was justifi able for the BMR study. In bringing SFAP to an operational use for the study of a city of several million inhabitants (covering some 5000 sq.km), NHA requested technical assistance from the ITC Department of Urban Survey and Human Settlement Analysis and the Royal Thai Air Force Reconnaissance Squadron (RTAF). TECHNICAL DETAILS OF THE BMR SFAP EXPERIMENT SFAP requires a small aircraft in order to reduce fuel consumption. The AU 23-A Peace Maker, normally used for taking photographs for reconnaissance purposes, was selected because the cost of fuel is approximately US $ 111 per hour whereas two engined types of aircraft consume approximately US $ 675 per hour or more. The camera was the Rollei SLX 55 x 55 mm format camera, equipped with an intervalometer developed at ITC, mounted on a plastic mounting base, fitting in the F-231 camera mount. The first three pieces of equipment were borrowed from ITC. Flight line navigation was observed by a navigation sight NT 1. The aircrew comprised three members: a pilot, a controller and a navigator. The RTAF undertook a test of SFAP over the city of Nakorn Pathom (60 km west of Bangkok) on October 18, 1984. The test was carried out to prove the capability of the staff involved, the equipment, the navigation and the photographic processing. The result of the test, which produced airphoto negatives at a scale of 1:47,000, was so satisfac tory that the decision to apply SFAP for the whole built-up area of BMR was confirmed. The area to be flown was divided into 4 zones. Each flight line was designed for 30 km (film length) and took approximately 10 minutes. The navigation was to follow a flight path which was along the center line of the square kilometer grids marked on the 1:50,000 air navigation chart. This provided the mean of identifying accurate land marks through the NT1 navigation sight. It follows that flight direction was then along N-S axis or E-W axis depending on wind direction. The 50 mm lens on the Rollei SLX camera, a flying height of 8,500 ft, which is below the height at which aircrews need oxygen, was calculated to give a useable ground coverage of 2 km square. Flight line intervals were of 2 km for a 60% forward overlap, a 80% side lap on both sides. Shutter speed is preset to 1/500 second, interval setting was calculated and set at 17.12 seconds because of the ground speed of 120 knots (222 km/hr) and the aperture was set to automatic. Kodak plus X film was used with 24 exposures. It was processed with very fine grain developer, such as microdol-X. Each negative has been clearly marked with its alpha-numerical code numbers for the flight index, and can be conveniently stored in an A4 size folder. The aerial photography took some 10 hours flying and was undertaken during January and February 1985. The first set of the enlarged SFAP at a scale of 1:15,000 was available for starting the interpreta tion tasks in the beginning of March 1985. The actual cost of SFAP for the single mission, including processing, enlarging and printing to finished photo scale 1:10,000 for an area of 5,000 sq.km, was Bht. 160,000 (US$ 6154) or Bht. 32 (US$ 1.18) per sq.km. Estimated cost of 1 set of conven tional aerial photograph of the same scale is Bht. 600,000 (US$ 23,70) or Bht. 128 (US$ 5) per sq.km. The SFAP coverage of BMR has demonstrated an operational procedure which other agencies can now employ as a means of obtaining a data for develop ment planning p low cost factor handling the ne photo enlarger, scale required development pla The SFAP airp to collect data - the locatic suitable fo - a general 1 - a quantific cording to This paper fc of the housing 5 A REVIEW OF A ESTIMATING PC In the liters with the proble Some relevant s Krause et al. ( dominant reside mm. B&W photos mented by 9 x £ 12,000, and 6,C determined the density’ associ An estimated pc tigation was ca function:- P = a r1 .e Where P = total ^1’ A RM’ ^TP Md D R1* D RM* E sities associat The result sh generally accur cities ranged f overestimate of enlarged airphc measurement dii sizes deviated Adeniyi (1983 et al. to deriv tion in Nigeria regression anal account for var tion density. 1 areas was based able including building type, ing and other e size, landscapi presence of gar ables, the resi classified in t example of clas Example code 1C These detaile airphoto scale sity, sample ar total residenti on stratified r were selected a In each block, family and numb building was co

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