METHOD OF SPACE IMAGES QUALITY IMPROVEMENT AT EARTH-VIEWING IN WINTER PHENOLOGICAL PERIOD

• Published in: Nauchno-tekhnicheskiĭ vestnik informat͡s︡ionnykh tekhnologiĭ, mekhaniki i optiki mekhaniki i optiki, 2019-01, Vol.19 (1), p.39
• Main Authors: Altukhov, A I, Shabakov, E I, Korshunov, D S
• Format: Article
• Language: Russian
• Subjects: Cartography; Earth surface; Exposure; Ill posed problems; Image contrast; Image quality; Pictures; Remote sensing; Satellite imagery; Snow cover; Solar radiation
• ISSN: 2226-1494; 2500-0373
• DOI: 10.17586/2226-1494-2019-19-1-39-46

Subject of research. During the winter phenological period, the largest part of the solar radiation flux is reflected from the earth's surface. The reason is the presence of snow cover on the earth's surface, which has high reflectance of the radiation flux. Under these conditions, the choice of shooting modes of the Earth from space is limited. Long exposure modes cannot be selected. As a result, the pictures have low quality and their interpretation is difficult. The proposed method provides the images of the earth's surface suitable for processing in view of the space survey features in winter phenological period. The method significance is confirmed by the results of the contrast evaluation of satellite images. Method. The method is based on the idea of co-processing of a series of space images with different exposures. The result of processing is a snapshot with an extended dynamic brightness range possessing high contrast in the areas of dark and pale halftones. Such snapshot displays better the borders and details of geographic area objects and that simplifies significantly its interpretation. Main results. We analyzed the effect of space survey ballistic conditions on the results of method application for image quality improvement in winter phenological period. The conclusion was drawn that the results of joint processing of images with different exposures can be ill-posed. The cause lies in geometric distortions due to continuous relative motion of the observed area and a spacecraft. The variant to eliminate geometric distortions by camera engineering development is proposed. Practical relevance. The prossessing method for the Earth's remote sensing data provides obtaining suitable for interpretation satellite images of the objects located on the earth surface in any phenological period. The results are applicable for the information accuracy increase in survey and cartography support.