NOAA-16/17, AVHRR, Coefficient Updates, Implementation Date 08 June 2004- Issued: Date issued 08 June 2004; time issued 18:2015 UTC

Tue 2:22 PM
Subject: NOAA-16/17, AVHRR, Coefficient Updates, Implementation Date 08 June 2004- Issued: Date issued 08 June 2004; time issued 18:2015 UTC

Calibration coefficient updates for June 2004

Date/Time(UTC) Message Issued:
08 June 2004 18:20 UTC

Satellite(s) Involved:
NOAA-16, and NOAA-17

Instrument(s) Involved:

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:
08 June 2004 15:50 UTC

Details/Specifics of Change:
The following update of the calibration coefficients are Implemented for:


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

The first orbits to be processed for NOAA-16 are:


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

The first orbits to be processed for NOAA-17 are:


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:

Cecil Paris
301-457-5247 ext 129

Emily Harrod
301-457-5247 ext 117

Web site(s) that contain other relevant information (where applicable): - History of level 1B
notices - All user notices - SOCC polar satellites status - SOCC morning reports