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Forestry
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The comprehensive inventory and monitoring
of forest and other renewable natural resources
by means of
Remote Sensing data
in the 'Three Norths' shelter forest region
The technical achievements made during the project
- Breakthroughs have been Achieved in Both The Comprehensive Evaluation Techniques of Remote Sensing Data and The Satellite Image Processing Techniques.
In the first stage of the comprehensive remote sensing inventory, Ping Quan county of Hebei province was selected as the typical experimental area. In Ping Quan experiment, Mulitple images of the same period were obtained from different space platforms and from aerial platforms of different heights, covering an area of 3,300 square kms. The images and photos obtained include Landsat MSS and TM images, SPOT HRV images, images taken by China Territory Satellite, as well as color 1R air photos on the scales of 1:130,000, 1:75,000 and 1:30,000. During the study, these images and photos were respectively evaluated according to multiple quantitative and qualitative factors, i.e. the geographic precision of the images, the precision of area measurement, the actual area of interpretable smallest objects, the visual interpretation results of boundary between different categories, the proportion of correct interpretation of patches for various categories, the area accuracy of patches for various categories, the cost and usability of images and photos, etc. In the meantime, a model was designed to make an integrated evaluation on the images and photos, and an integrated index was used to quantitatively describe the general effect of visual interpretation. Thus theoretical foundation was laid down for the evaluation of application potentials of various remote sensing images in the Landsat TM images as the backborn, with the Chinese satellite images and color IR air photos on the scale of 1:130,000 as auxiliary data in partial area was optimal combination of information source, both technically and economically, for the project. The SPOT images also possess its own technical advantages, however its was a pity that the problem to receive the SPOT data in China has not been solved and the images were not widely used .
The project were carried out overall researches on processing techniques of a new generation of remote sensing images. According to the characteristics and needs of remote sensing inventory of renewable resources, peculiar information extraction techniques and the scheme about images scale, images seasons and bands combinations were proposed. For example, a method of superiority index factor was proposed for the evaluation of color composition of radioed images, which could quantitatively determine the optimal combination and thus avoid a host of experiments. Such work laid a foundation for the image processing techniques to transfer from optical processing to a stage of computer-optical one in large area remote sensing inventory.
- New Developments have been Achieved in the Techniques of the Comprehensive Remote Sensing Inventory and Serial Thematic Mapping.
In the comprehensive remote sensing inventory. The different specialties could share the information sources and field work data thus saving human and material resources .The mutual comparison and coordination among the thematic , maps serial mapping have improved the mapping quality obviously but the comprehensive inventory and serial mapping is different from traditional technique .Especially the natural conditions of the vast 'Three North's region are complicated and the social and economic conditions are in great disparity. Therefore it is really an important task for this research to draw up a unified technical scheme to coordinate investigation contents classification systems and mapping methods of various specialties to guarantee the quality of the comprehensive remote sensing inventory and serial mapping the technical scheme formulated on the basis of the results of Ping Quan remote sensing Experiment by has brought about a important progress both scientifically and practically.
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