General trends of space remote sensmg technology are overviewed from the non-renewable earth resources stand point. Since the launch of Landsat-1 by NASA, in both Japan and US the applicabilities of space technology for the assessment of global resources have been extensively investigated, hence in this paper general movements of Landsat project, including future Landsat-D, are explained as well as other related US projects such as the ones which utilize future shuttle flights. In addition, some brief concepts on European space activities, especially on French satellite "SPOT" are studied. Furthermore, the importance of understanding the general international situations which Japan has to take into account bor its own projects is emphasized and discussed.
A manual of analyzing structural features using LANDSAT imagery is reviewed on a basis of previous and recent works, which have been conducted by the author and his colleagus for the most part of the Japanese archipelago. For general purpose of geological analysis it is recommended to use black and white photos of bands 5 and 7, and false color photo prepared in scale of 1/500, 000. In case of detecting detailed structural features, the photos could be enlarged to a scale of 1/200, 000. The main geological features detectable on LANDSAT imagery are geological units, bedding and foliation, folds, lineaments (tectonic line, fault, dike etc.), topographic features, and the anomalies such as mineral alternation. The lineaments are particularly the easiest feature to be studied and it is practically advisable to complete the lineament pattern for the first step of the analysis. For further studies of LANDSAT interpretation of the surface geological structure, two new techniques have been proved practically useful; Edge enhancement and mosaic-making technique is quite helpful for analysis of lineament pattern. Manual treatment using band 7 has been successfully tried in four different directions. Digital treatment using computer has been also conducted. The first order of directional differentiation processing made in false color prints of bands 4, 5, and 7, the most simple form among possible digital processing with edge enhancement idea, has been proved very practical. The mosaic of LANDSAT imagery would be useful to obtain a quick look of regional geologic structure in a large area.
LANDSAT MSS data of Niigata Oil Field are digitally processed to enhance geomorphological and geological features. Most of the pages are devoted to following processes: Special Filtering, Visual Lineament Extraction and Ratioing. The effects of these processes are theoretically discussed. The author wants to emphasize that the cooperative works between geologists or geophysicists and computer technicians are required to use remote sensing data for geological and geophysical interpretation.
In order to select an appropriate sort of imageries for a purpose of geological analyses, 18 frames data processed by the computer ploting, digitally, from CCT recorded the same region over Niigata oil bearing basins, have been studied analitycally under optical observation, based on geologic elemental features such as minor lineaments, major lineaments, circular anomalies, land-form units boundaries, and traceable strike ridge lines indicating trends of folding structures. Test imageries of 18 frames consist of followings: 1) Principal component false color, 2) original B/W prints, Band-5, -7, 3) 3-Band composite false color, 4) B/W copies ratioed with 2-Band combinations directly and logarithmically, 5) two ratioed false color composites. In this report, some of main analytical overlays carried out by three groups each of which is consisted of two geologists, are shown comparatively with their data imageries. Descriptive tables and interesting figures from the comparison between data in quantitative volumes and differences in imagery qualities, are shown plainly, too, as the results of the work, with distinct conclusions about selecting imagery processing, methods of analyses, and some problems to be regarded.
Detection of various anomalies possibly related to geological origin through the use of LANDSAT imageries seems to be one of the most fundamental and significant roles of remote sensing. As a tool of preliminary evaluation for petroleum exploration, remote sensing could be a useful one because LANDSAT imageries cover almost all of the world and they may be obtained at inexpensive price. Certain studies have indicated that the use of LANDSAT imageries would contribute to pinpoint the hydrocarbon productive area and also to reduce the exploration cost. Subsurface petroleum traps may create some reflective features on the earth's surface, such as dip reversals or other geomorphological anomalies. Major faults sometimes relating to buried hill structures or providing the carriers or seals for the secondary migration of hydrocarbons could also furnish anomalies such as lineaments to the surface. In this paper, case studies of detection of the above mentioned anomalies in Burma and the North China Basin are presented. Further, the importance of integration of remote sensing data with other geological and geophysical information is emphasized.
Geologic interpretation of LANDSAT imageries has been considered to be useful method for petroleum exploration at the early stage because of following advantages; wide area coverage, low cost, easy data availability and computer processing ability. In the article, some examples of LANDSAT imageries and geologic interpretation of oil fields over arid regions are shown. General geologic interpretations such as structure analysis and geologic unit classification and the detection of major lineaments, which may suggest large fracture system, are possible. They may be important basic information for petroleum exploration.
In the densely vegetated regions, tone anomalies probably caused by slight topographic and cover change, are detectable on LANDSAT imageries. In the article, three examples of tone anomalies which show good correlation with existing oil and gas fields, are presented.