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GOES imagery displayed using different unit scales or different display systems

GOES imagery is collected in 10-bit values called GVAR counts, whereas image display systems use 8-bit displays. The process of converting from 10-bit GVAR counts into 8-bit display counts is not merely a linear divide by 4 process. The image examples in the links below help explain the non-linear process of converting from 10 bits to 8 bits. Comparisons are made between image displays in 10-bit GVAR counts and in 8-bit display counts for both visible and infrared imagery. In addition, a comparison is made between the standard (McIDAS/RAMSDIS) 8-bit display and the GINI (AWIPS) 8-bit display used only for GOES water vapor imagery. Another comparison is made between the fog product as generated and displayed on RAMSDIS and AWIPS.

Also, note that the process of converting between units is called scaling, whereas the calibration of GOES imagery is done before data is made available to end users.


Weinreb, M., et al, 1997: Operational Calibration of Geostationary Operational Environmental Satellite-8 and -9 Imagers and Sounders, Applied Optics, 36(27), September 20, pp. 6895-6904.

Weinreb, M., et al, 1997: Operational Calibration of the Imagers and Sounders on the GOES-8 and -9 Satellites, NOAA Technical Memorandum NESDIS 44, February, 32 p.

Hillger, D.W., 1999: GOES Imager and Sounder calibration, scaling, and image quality. NOAA Technical Report NESDIS 93, June, 34-p.

Links to other Web pages with GOES calibration/scaling information:

Back to RAMM Branch GOES image display page.