[nws-changes] 20071207: GOES update

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20071207: GOES update
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 07 Dec 2007 06:52:16 -0700

To:
Brian.Hughes@xxxxxxxx


Topic: GOES-10 GVAR and Services Rebroadcast and Product Update
Message Issued: December 6, 2007, 2145 UTC
Satellites Impacted: GOES-10
Products Impacted: GOES-10 GVAR, LRIT, and DCS Rebroadcast. GINI
Processing. GOES-10 Visible Calibration
Date/Time of Initial Impact: December 5, 2007  1530 UTC
--------------------------
Details:

The following are updates on GOES-10 activities to cover for the outage
of GOES-12:

GVAR and Ancillary Services Rebroadcast:

GOES-10 GVAR, LRIT, and DCS are being rebroadcast through GOES-12.
Direct users do not need to repoint their antenna to GOES-10 to receive
these services. However, please be advised that due to activities
involving the recovery of GOES-12, users who are receiving data
transmitted through GOES-12 may experience dropouts between 2100 UTC and
0100 UTC.


GINI Processing:

NESDIS and NWS has identified the issue with the East CONUS Water Vapor
4 km Regional and Puerto Rico Regional Water Vapor 4 km imagery being
transmitted through NOAAPORT. The NWS has corrected this and users
should be receiving the products.

NESDIS is still investigating the problem with the GOES Sounder Derived
Products (TPW, LI, CTP, and SKT) as well as the distribution of High
Density Winds.



GOES-10 Visible Calibration:

The following was received from NESDIS/STAR regarding GOES-10 Visible
Calibration:

You can use the following for GOES-10 Imager visible channel
post-launch calibration:

   R_post = 1.2248  * exp(0.04389*t ) * R_pre
   A_post = 1.2248  * exp(0.04389*t ) * A_pre

where R_pre and A_pre is pre-launch calibration to convert count to
radiance and nominal reflectance, respectively; R_post and A_post is
post-launch calibration correction for radiance and nominal reflectance,
respectively; and t is number of years since January 1, 2000.

   For example, if the GVAR count of a GOES-10 Imager visible channel
measurement is 129 on Dec 6, 2007, the radiance and nominal reflectance
for this measurement, using pre-launch calibration, is

   R_pre = 0.5582 * (129-29) = 55.82 W•m-2•sr-1•µm-1
   A_pre = 0.001110 * (129-29) = 11.1%

[NOTE: most users obtain these radiance or reflectance automatically by
default.] The radiance and nominal reflectance for this measurement,
considering instrument degradation since launch, is

   R_post = 1.2248  * exp(0.04389*7.9315) * R_pre = 1.7348 * 55.82 =
96.84 W•m-2•sr-1•µm-1
   A_post = 1.2248  * exp(0.04389*7.9315) * A_pre = 1.7348 * 11.1% = 19.3%

Please visit
http://www.orbit.nesdis.noaa.gov/smcd/spb/fwu/solar_cal/GOES_Cal.html#prelaunch
or contact Xiangqian Wu <Xiangqian.Wu@xxxxxxxx> for more information.

   These post-launch calibration coefficients were based on our study
in 2005. Early next week we will have an update on these coefficients,
using more recent data. The probability is low for the future update to
differ from the above coefficients by more than 5%.



---------------------------
Contact Information:
Brian Hughes
Satellite Services Division
NOAA/NESDIS/OSDPD
301-763-8051 x106
Brian.Hughes@xxxxxxxx

See http://www.ssd.noaa.gov/PS/SATS/messages.html  for this and other
satellite related messages.
See http://www.ssd.noaa.gov for full GOES scanning schedu