Abstract
At present, NOAA/AVHRR 10-day mosaic composite image for the total Asian region is undertaking. This paper is concerned with development of an algorithm to extract optimal data for the purpose. Generally, such algorithm is required to reject cloud data at least, and to pick up less distorted data radiometirically and geometrically. As the first step, by using ground truth data, simulation by 6S code and NOAA/AVHRR image data in Mongolia, effects of atmosphere and bidirectional reflectance were investigated in this Part-1. The apparent reflectance of channels 1 and 2 were highly dependent upon the sun-target-sensor geometry, and the magnitude of disturbances was dependent upon ground covers. Finally, NDVI levels to the maximum NDVI value versus to sensor scan angle in AVHRR scenes for various ground cover conditions were investigated. Further investigation is necessary to establish a more efficient compositing algorithm.
