Topic:
Visible Calibration Monthly Update for March
Date/Time(UTC) Message Issued:
6 March 2003, 1430 UTC
Satellite(s) Involved:
NOAA-16
Instrument(s) Involved:
AVHRR
Product(s) Involved/Affected:
Channel 1, 2, 3A visible calibration
Date/Time(UTC) of Initial Implementation:
11 March 2003
Details/Specifics of Change:
No changes are planned for the visible calibration values this month.
However, the "breakpoint" values used in our level 1B processing must be
updated. No change is required by the user. Breakpoints are used within
our level 1B preprocessor to determine the point at which to switch the
visible coefficient used for performing calibration. The switch is
determined as indicated below:
Channel 1: Low - slope = 0.0523; intercept = -2.016; breakpoint =
count < 498.96
High - slope = 0.1528; intercept = -51.91; breakpoint
= count > 498.96
Channel 2: Low - slope = 0.0513; intercept = -1.943; breakpoint =
count < 500.16
High - slope = 0.1510; intercept = -51.77; breakpoint
= count > 500.16
Channel 3A: Low - slope = 0.0262; intercept = -1.010; breakpoint =
count < 499.43
High - slope = 0.1920; intercept = -84.20;
breakpoint = count > 499.43
"Count" is the 10-bit digital count as recorded by the AVHRR instrument
Contact Person(s) Name/Email/Phone Number for Questions:
Robert.Levin@noaa.gov/301-457-5247 ext. 124 (Information Processing
Division calibration lead)
Xiangqian.Wu@noaa.gov/301-763-8136 ext. 138 (Office of Research and
Applications instrument scientist)
Web site(s) that contain other relevant information (where applicable):
http://noaasis.noaa.gov/NOAASIS/ml/calibration.html - NOAASIS Satellite
Instrument Calibration web site
http://www.oso.noaa.gov/daily-news/index.htm - SOCC morning reports
http://www.osdpd.noaa.gov/PSB/PPP/PPP.html - History of level 1B
notices
http://www.ssd.noaa.gov/PS/SATS/messages.html - All user notices
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