NOAA-15 and 16, HIRS Visible Calibration Update.
Date/Time(UTC) Message Issued:
24 July 2002 2330 UTC
NOAA-15 and 16
Level 1B and 1B*
Date/Time(UTC) of Initial Implementation:
20 August 2002
Details/Specifics of Change:
On May 10, 2002, a notice was sent out to the user community announcing
preparations to update the NOAA-15 and 16 HIRS visible coefficients. Test
data is now available on the CEMSCS and anonymous FTP site
(psbsgi1.nesdis.noaa.gov in subdirectory pub\test1b\vicarious). Below is
a list of HIRS 1B test data sets (P1B...) containing NOAA-15/16 HIRS
vicarious coefficients for channel 20 and accompanying GHRR and AMSUA 1B
test data sets as well as corresponding operational data sets (NSS...) that
are available on the anonymous ftp site. This test data will be updated no
more than twice a week unless a request is received for additional data.
Test data on the CEMSCS will run in parallel to the operations.
The changes will go into operations on August 20, 2002.
Below is the new values, current, and prelaunch.
NOAA-15 Vicarious Operation Prelaunch
Slope 0.03174 0.0674 0.02336
Intercept 47.1100 101.0635 36.0500
NOAA-16 Vicarious Operation Prelaunch
Slope 0.02611 0.021354 0.021354
Intercept 62.3307 51.4852 51.4852
From Dr. Cao's notes - "To retrieve the albedo from the HIRS level 1b data,
the following equation should be used:
Albedo = (intercept + slope * C)/cos(z)
Where C is the Earth view count and z is the solar zenith angle for the
pixel. All items are available in the level 1b data."
Test data on anonymous FTP site:
Web site(s) that contain other relevant information (where applicable):
http://www.osdpd.noaa.gov/PSB/PPP/PPP.html - History of level 1B