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Hi Stacy, re: > One more thing . . . I've found some information online that describes > how to convert the goes12 imager counts to radiance and then to > temperature, but they're all based on 10bit raw count values. Are there > look-up tables for the 8bit data, or should I just mulitply the values > in the 8bit files by 4 and use the existing instructions The 1-byte images broadcast in the Unidata-Wisconsin datastream (IDD feedtype UNIWISC aka MCIDAS) are pre-calibrated: the mapping of brightness (0-255) to temperature (K) is represented by the following two-slope relationship: T[K] BRIT (0-255) ----- ------ 163 255 241.9999 177 242 176 330 0 i.e.: 163 K <-> 255 brightness 241.9999 K <-> 177 brightness 242 K <-> 176 brightness 330 K <-> 0 brightness This relationship holds for all IR channels (3.9 um, 6.5 um (GOES-12) or 6.8 um (GOES-10), 10.7 um, and 13.3 um (GOES-12) or 12.0 um (GOES-10). > . . . in other > words, replace "X" in the equations below with (X*4)?? You should use the two slope relationship above. > These are the equations I found: > > R = (X - b)/m, where R=radiance, X = GVAR count, m and b = constants > > T(eff) = (c2 * n) / (ln [1 + (c1 * n^3)/R), T(eff) = effective temp, R = > radiance, c1, c2, & n = constants > > T = a + b * T(eff), T = actual temp, T(eff) = effective temp, a & b = > constants > > Thanks. No worries. Cheers, Tom **************************************************************************** Unidata User Support UCAR Unidata Program (303) 497-8642 P.O. Box 3000 address@hidden Boulder, CO 80307 ---------------------------------------------------------------------------- Unidata HomePage http://www.unidata.ucar.edu **************************************************************************** Ticket Details =================== Ticket ID: OMB-868480 Department: Support Datastream Priority: Normal Status: Closed