MSS data from satellites or aircrafts are influenced by the atmospheric absorption and scattering generally called the atmospheric effects and by the shade of objects in the field of vision. On the other hand because the angular field of view of scanneres placed on aircrafts is usualy large, these effects chage in step with a change of scanning angle. In this paper the relationship between the scanning condition and this kind of noise in the scanning direction is investigated. A method to remove it is proposed and is compared with usual methods. Further the correction effect of the proposed method on the land-use classification is examined. Content of the result is summarized as follows. (1) The shade and optical air mass do not have much an influence on the noise in the scanning direction and the shade effect is proportional to the scanning angle θi. (2) The noise mainly depends on a change of the scattered radiation strength in step with a change of the angle ;is, between the scanning direction and the sun ray and it can be almost expressed by the second order formula for θsi. (3) In comparison with usual methods to remove the noise, the simple method that we propose in this paper do not have serious effects on the original characteristic of covertures on the surface of the earth. (4) The accuracy of the land-use classification fairly increeses by using this correction method.
The image overlay processing of multi-temporal images is a new processing method to extract small changes within different images, in which classification results of images and geographical information are overlaid using a piccell as a unit. The method was adopted in analyzing landcover of Toyonaka City, Osaka Prefecture, using LANDSAT MSS data of four seasons. The landcover was classified into five categories, of which areal ratios were calculated. Seasonal changes in landcover were recognized, such as a partial replacement of bare land by grass land from winter to summer. The result shows that the method proposed in this paper is effective for extraction of small changes within different images, and that the seasonal change should be considered in analyzing landcover. The method can be applied to update, landuse information by overlaying landuse maps previously prepared and landcover map derived from recent LANDSAT data, and to discriminate disaster dangerousness by overlaying classification results of LANDSAT images and geographical information.
Microwave Scanning Radiometer (MSR) is one of the sensors on board Japan's first Marine Observation Satellite (MOS-1) which will be launched in 1987. Ground-based microwave experiments for snowpack properties using Bread Board Model (BB-M) of MSR have been carried out under cooperative project between National Space Development Agency of Japan and National Resources Laboratory, Science and Technology Agency since 1982. Based on brightness temperature data collected at the ground experiments, this study shows that two major snowpack parameters, snow depth and snow water equivalent may be estimated by the MSR. Two stages of analyses adopted were discriminating presence or absence of snow, and dry or wet snow, respectively. For the dry snow data discriminated, multiple regression analysis was made to estimate the snow depth and the snow water equivalent. Although reliability of the estimation should be verified for further analysis, the analytical method developed here using selected data sets for estimating snowpack parameters is practical enough to be operational and expected to incorporate with an automatic data analysis procedure which synergistically utilizes different type of sensor data.
Marine Observation Satellite-1 (MOS-1) named "Momo(peach)-1" was successfully launched form Tanegashima Space Center, NASDA by N-II rocket and put into the expected orbit on Feb.19, 1987. The first MESSR image was obtained on Feb.23, 1987, four days after the launch. All conditions of both satellite and ground station are very good. NASDA planned to conduct MOS-1 Verification Program (MVP) by using MOS-1 data, airborne data, truth data and others in collaboration with domestic and foreign agencies (76 agencies) and distribute MOS-1 data free of charge to those who participate in the MVP. NASDA will distribute MOS-1 data with fee to general user from November during the routine operation period. In order to analyze MOS-1 data, it is necessary to know the outline of MOS-1 system, data format and others. This paper describes the outline of MOS-1 operation and the MVP. The first MESSR image and other MESSR images are also presented.