The Following Data Months Will Not Be Processed Through 
S-10N/S-4N/S-4GN Products:


August 1993: Nonscanner instrument powered off because of battery cell
failure/spacecraft power problems.

September 1993: Nonscanner instrument powered off because of battery
cell failure/spacecraft power problems.

October 1993: Nonscanner instrument powered off because of battery
cell failure/spacecraft power problems.

November 1993: Nonscanner instrument powered off because of battery
cell failure/spacecraft power problems.

March 1998: Nonscanner instrument powered off because of spacecraft
Digital Telemetry Unit (DTU-1) failure.  Switch to All-Experiment data
format.

December 1998: Nonscanner instrument powered off because of battery
cell failure/spacecraft power problems.

January 1999: Nonscanner instrument powered off because of spacecraft
attitude anomaly resulting from insufficient spacecraft power.


September 7, 1999

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The ERBE data independent nonscanner processing software accounts 
for the outgoing longwave radiation (OLR) diurnal cycle over land 
and desert regions by fitting a constant value through the 
nighttime data and a half-sine fit through the daytime data for 
the month. The precession of the ERBS orbit causes sampling patterns 
that result in some regions having poor temporal sampling for 
computing the monthly mean reflected solar radiation and OLR.  
March data months in particular are affected by this temporal 
sampling problem.  Regions at high latitudes sometimes have daytime 
measurements only near sunrise and/or sunset.  With this
sampling pattern, the half-sine fit to the daytime data becomes very
sensitive to random variations of OLR at the measurement times.  The
monthly mean albedo computed from a limited data set also has errors
due to random variations.

The ERBS data has been reprocessed with a modified data processing
algorithm that calculates a temporal sampling error for each region.
For regions with unacceptably large temporal sampling errors, monthly
mean values of OLR, albedo, and SWR are replaced with fill values 
in the S-10N data product.  These fill values will appear in the S-4N
and S-4GN products.  The reprocessed data products have not yet been
approved for archival.  Once the ERBS data has been approved for
archival, the NOAA-9 and NOAA-10 ERBE data sets will be reprocessed
with the modified algorithm.

September 7, 1999