GOES-8 Sounder Description

GOES-8 Sounder Description

Sounder characteristics

The GOES-8 sounder (see Table 1 for instrument features) has 18 thermal infrared bands plus a low-resolution visible band. The field of view is 8 km and is sampled every 10 km; 13 bit data is transmitted. The GOES-8 sounder spectral selection was mostly patterned after the High-resolution Infrared Radiation Sounder (HIRS) carried on the NOAA polar-orbiting satellite. It has six bands in the 15 um (longwave) band, a split-window pair, three midtropospheric water-sensitive bands and an ozone band (midwave), five 4 um (shortwave) bands, and a visible band. The spectral bands, some at wavelengths never obtained before in geosynchronous orbit, are sensitive to temperature, moisture, and ozone. Table 2 summarizes the spectral band performance characteristics for the GOES-8 sounder, measured in-flight. Table 3 shows the in-flight determination of noise performance of the GOES-8 sounder and compares it with the GOES-7 VAS and NOAA-12 HIRS performance. The GOES-8 sounder's design goal, like the imager's, is to provide brightness temperatures with 1.0K absolute accuracy and 0.3K relative precision. The quality of the absolute calibration is evident when collocated GOES-8 sounder and VAS radiances are compared; the brightness temperatures for the different spectral bands on each instrument are charted as a function of wavenumber. The GOES-8 sounder and VAS radiances agree within 2.0K; the GOES-8 sounder's additional spectral bands provide more atmospheric detail. The full-time availability of the GOES-8 sounder enables operational sounding products for the first time; this has the potential for contributing significantly to mesoscale forecasting over the conterminous United States, monitoring thermal winds over oceans, and supplementing the Automated Surface Observing System (ASOS) with upper-level cloud information. The GOES-8 sounder will also allow for the development of a number of advanced products.

Sounder imagery

The following imagery demonstrates the sounder's capabilities for a representative sampling of its long, mid, and short-wave spectral bands:

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Last Modified:25-Apr-95