From:
10:47 AM
Subject: NOAA-KLM, HIRS, AIP and HIRS, Level 1B Local Azimuth Angle, 13 May
1998 - Issued: 13 October 2004; time issued 1445
UTCResent-From: nesdis.osdpd.ipd.Level-1B.notices@noaa.gov,
nesdis.osdpd.ipd.contractors@noaa.gov
To: undisclosed-recipients:;
Topic:
Relative Azimuth reported in the Satellite or Local Azimuth Angle Level
1B/1B* fields
Date/Time(UTC) Message Issued:
6 October 2004/1445 UTC
Satellite(s) Involved:
NOAA-15, 16, and 17
Instrument(s) Involved:
HIRS, AMSU-A, AMSU-B, and MHS
Product(s) Involved/Affected:
All/No changes
Date/Time(UTC) of Initial Implementation:
13 May 1998, at NOAA-15 launch
Details/Specifics of Change:
Currently, in the operational level 1B and 1B*, the "relative azimuth angle"
is provided in a field described in documentation as "local azimuth angle".
Since the launch of NOAA-15, this field has contained the "relative azimuth
angle" not local or satellite azimuth angle. We believe that the user
community is aware of this and is using the angle correctly in their product
systems. However, the documentation must be changed to be consistent with
the actual data provided. Therefore, in the KLM Users' Guide all references
to "satellite azimuth angle" or "local azimuth angle" must be replaced with
"relative azimuth angle". This affects the documentation for the AMSU-A,
AMSU-B, HIRS, and MHS instruments. For 1b users this modification will have
no effect, since relative azimuth angles have always been provided (the 1b
documentation has just been wrong, or at best, misleading). For IPD internal
1B* users, this includes changing the 1b* item
name "SATELLITE_AZIMUTH_ANGLE" to "RELATIVE_AZIMUTH_ANGLE" in the 1b* data
dictionaries and updating its definition accordingly. For 1b* users that
access this field, a trivial change to their code is needed (same change
needed to support the new NOAA-N/IJPS formats). We hope that this has not
created a problem for anyone. Please contact us if you have questions or
concerns. Thank you for your continued support.
Contact Person(s) Name/Email/Phone Number for Questions:
Emily.Harrod@noaa.gov/301-457-5247 ext. 117
Vincent.Tabor@noaa.gov/301-457-5247 ext. 137
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
--
*******************************************
*
* Emily D. Harrod
* NOAA/NESDIS/OSDPD/IPD
* Product Systems Branch
* Pre-Product Processing Group
* E/SP13, Federal Building #4, room 0318
* 5200 Auth Road
* Suitland, Maryland 20746-4304
* USA
* voice 301-457-5247 ext 117
* fax 301-457-5199
* email Emily.Harrod@noaa.gov
*