ＣＯＲＯＮＡ衛星写真ポジフィルムのデジタル化による利用とその有効性 中国トルファン盆地の活断層と遺跡を例に

Abstract

The purpose of this paper is to discuss the digitization of CORONA Satellite Photographs Positive Film (CSPPF) and its availability based on actual data of constructions and field survey, focusing on the active faults and the historical ruins of the Turpan Basin, North West of China. The following results were obtained : 1) The direct stereo-optical interpretation of the CSPPF with two zoom lupes, providing more detailed information than a single image, targets with a diameter of 4 m and lineament, such as active faults, with 5 m relative height can be recognized.2) Two kinds of the digitized CSPPF image, namely Direct Digitized Image (DDI) and Expanded Digitized Image (EDI), were used for the detailed interpretation results. Digitization of the CSPPF makes it easy to exhibit the interpretation results and the stereooptical images through image processing.3) Both the target with a diameter of 7 m on the EDI and those of 10 m on the DDI can be recognized. The low linear object with a relative height of 5 m such as fault scarps and walls of ruins are also recognized on both images. Concluding from the above, DDI has sufficient resolution to interpret and display low fault scarps and cliffs of terraces.4) Both positive and negative films can be digitized, but with the former it is easier to obtain the actual image than the latter. It is efficient to select positive films to interpret small targets such as watch-towers.