From:
11:10 AM
Subject: NOAA-16/17, AVHRR, Coefficient Updates, Implementation Date 08 June 2004- Issued: Date issued 26 May 2004; time issued 15:15 UTC
Resent-From: nesdis.osdpd.ipd.Level-1B.notices@noaa.gov,
NESDIS.OSDPD.IPD.all.hands@noaa.gov
Topic:
Calibration coefficient updates for June 2004
Date/Time(UTC) Message Issued:
26 May 2004 15:15 UTC
Satellite(s) Involved:
NOAA-16, and NOAA-17
Instrument(s) Involved:
AVHRR....
Product(s) Involved/Affected:
Products using channels 1 and 2 for NOAA-16
Products using channels 1,2, and 3 for NOAA-17
Date/Time(UTC) of Initial Implementation:
To be announced at a later date
Details/Specifics of Change:
The following update of the calibration coefficients are recommended for:
NOAA-16 AVHRR
Ch_1_lo = .05341*count - 2.059, count<498.96
Ch_1_hi = 0.1559*count - 52.98, count>498.96
Ch_2_lo = .05799*count - 2.191, count<500.16
Ch_2_hi = 0.1709*count - 58.64, count>500.16
NOAA-17 AVHRR
Ch_1_lo = .05430*count - 2.173, count<501.12
Ch_1_hi = 0.1594*count - 54.85, count>501.12
Ch_2_lo = .06562*count - 2.576, count<500.73
Ch_2_hi = 0.1953*count - 67.63, count>500.73
Ch_3_lo = .03097*count - 1.306, count<501.37
Ch_3_hi = 0.2171*count - 94.78, count>501.37
on June 8. These coefficients are intended to be optimal on June 25, in the
middle of the two scheduled updates.
For NOAA-16 AVHRR, this is a regular update with incremental changes in
calibration coefficients. Recent NOAA-16 AVHRR data show increasing
irregularity, particularly for Channel 2. We are closely monitoring the
instrument performance and its impact on vicarious calibration.
For NOAA-17 AVHRR, this is the initial update with significant changes
in calibration coefficients from their pre-launch values. Compared with the
data calibrated by the pre-launch values, the data calibrated by the new
coefficients typically show a 2.0% reduction in Channel 1, a 20.7% increase
in Channel 2, and a 16.9% increase in Channel 3A. Note also the count values
for the dual-gain operation (the "break point"), which may differ from the
values
provided earlier by instrument vendor.
We plan to update these coefficients monthly and we do not anticipate
significant changes in future regular update.
Contact Person(s) Name/Email/Phone Number for Questions:
Xiangqian Wu (Xiangqian.Wu@noaa.gov)
Physical Scientist, NOAA/NESDIS/ORA
E/RA2, Office 7214, 5200 Auth Rd.
Camp Springs, MD 20746-4304
Phone: 301-763-8136 ext. 138
FAX: 301-763-8580
Cecil Paris
301-457-5247 ext 129
cecil.paris@noaa.gov
Web site(s) that contain other relevant information (where applicable):
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
http://www.oso.noaa.gov/poesstatus/ - SOCC polar satellites status
http://www.oso.noaa.gov/daily-news/index.htm - SOCC morning reports