Abstract
VISSR (Visible and Infrared Spin Scan Radiometer) image data observed by GMS (Geostationary Meteorological Satellite) have been stored since March 1981 in the MSC (Meteorological Satellite Center). Since storage media and data formats used in the MSC are designed for a large-scale computer system, those data are yet in limited use.
For easy processing of VISSR image data on personal computers, a procedure to convert image data from MT (Magnetic Tape) or CT (Cartridge Tape) in the MSC into floppy disk by resampling has been developed since 1988 by the author. Following problems, however, are arisen in resampling from original VISSR image data.
1. Ratio of pixel number density on a floppy disk to that of original VISSR changes with location on the earth.
2. Observed scan lines are not usually parallel to the latitudinal line and therefore some information on each scan line is more or less obscured. Users can not exactly extract observed time and channel name (on the visible data) of a pixel.
3. A usable image on a personal computer is necessarily limited in region and resolution, resulted from the preceding resampling.
In order to solve these problems an image mapping technique with a new format of the image data for personal computers is developed. This mapping is derived without losing accuracy by a simplified mapping method currently used for a large-scale computer in the MSC.
These image data on a-floppy disk, though the size to be treated is necessarily small, make it possible for personal computer users to deal with VISSR image data in original resolution both on space and temperature (or reflective intensity). Personal computer user then will be able to analyze in more detail the field of the sea surface temperature and/or cloud distribution of various meteorological phenomena such as meso-scale disturbance.
Some example of application of technique de-scribed are also shown in this paper.
