Table 2. Noise characteristics of the infrared channels of the GOES-5 VAS

                In-flight                            Single spatial
               single-sample                             sample             Typical sounding
                  noise            Typical spin           noise                 brightness
Channel               budget(a)                    noise(b) (K)
-------        -------------       ------------       -------------         -----------------
   1               2.740                 1                2.740                    0.6
   2               1.360                 4                0.680                    0.2
   3               1.020                 4                0.510                    0.2
   4               0.940                 2                0.660                    0.2
   5               0.760                 2                0.540                    0.2
   6               0.028                 4                0.014                    0.2
   7               0.640                 2                0.450                    0.2
   8               0.100                 1                0.100                    0.1
   9               0.650                 4                0.325                    0.2
  10               0.150                 1                0.150                    0.2
  11               0.029                 4                0.015                    0.2
  12               0.009                 1                0.009                    0.1
                         Spin budget  = 30 
--------------------
(a)  The spin budget for the current VAS on GOES 7 can be reduced to 20 for measurements using
     the small infrared detectors (personal communication with W. P. Menzel 1991).
(b)  After averaging 25 radiance samples in one sounding area. This reduces the spin budget
     significantly, but at the cost of spatial resolution (after Table 1 of Smith 1983).