[IGSMAIL-3522]: Occultation data from the SAC-C spacecraft

[Tony Mannucci]

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IGS Electronic Mail      13 Sep 10:43:44 PDT 2001      Message Number 3522
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Author: Tony Mannucci

Dear IGS Colleagues,

I am pleased to announce the availability of preliminary atmospheric 
and ionospheric occultation data acquired from JPL's Blackjack GPS 
receiver onboard the SAC-C spacecraft. For each occultation event, we 
are distributing the raw phase observables at both GPS frequencies 
from two GPS satellites in view of the rear-facing antenna, an 
occulting satellite and a high elevation satellite used for 
calibration purposes. The data can be downloaded via anonymous ftp. 
Information is provided at the end of this notice.

We ask the following of those who choose to download and analyse these data:

1. Please send an email to Gerald Manipon at 
leoops at sdsio.jpl.nasa.gov announcing your intention to download the 
data.
2. Please use these results exclusively for internal evaluation and 
testing purposes. A future announcement is expected in about two 
months when the data are ready for scientific analyses.
3. Send inquiries to Gerald Manipon at leoops at sdsio.jpl.nasa.gov. We 
cannot promise support beyond what is available in the ftp area.

These data are primarily intended for evaluation and testing by 
groups familiar with the technical details of occultation processing. 
No atmospheric retrieval parameters are currently being made 
available. An announcement will be made when these higher level 
products are available on the GENESIS Earth science information 
database (http://genesis.jpl.nasa.gov).

The occultation capability onboard the spacecraft is still under 
development, and it is understood that changes to the data formats 
and acquisition modes will be occurring from time to time. General 
status notices will be posted on a best efforts basis in a text file 
in the ftp area (see below).

High-rate ground data useful in processing these occultations are 
available from the International GPS Service (IGS) (See IGSLEO 
message number 9 at 
http://igscb.jpl.nasa.gov/mail/igsleo/igsleo.html).

The availability of these data is the result of outstanding effort 
from a number of individuals within the following groups and 
institutions:

CONAE (Argentine space agency)
GENESIS group at JPL
GPS Earth Observatory group at JPL
GPS Systems group at JPL
International GPS Service
NASA
Orbiter and Radiometric Systems group at JPL
Raytheon Technical Services Company
Satellite Geodesy and Geodynamics Systems group at JPL

DATA DOWNLOAD INFORMATION
----------------------------
Use anonymous ftp to the following address:
ftp://sideshow.jpl.nasa.gov/pub/genesis/level0/sac-c/

Source code for the data reader is in 
ftp://sideshow.jpl.nasa.gov/pub/genesis/level0/sac-c/Software/BJfmtl.c. 


Additional documentation is contained in:
ftp://sideshow.jpl.nasa.gov/pub/genesis/level0/sac-c/Documents/

README.BJfmtl describes the reader, BJfmtl.c .
README.010803 describes the data.
README.receiver contains receiver status information.

General information on the SAC-C satellite is available from: 
http://pao.gsfc.nasa.gov/gsfc/missions/projects/sac-c.htm 
http://orbis.conae.gov.ar/sac-c/

--
Tony Mannucci
Task Manager, GPS Earth Observatory project
Jet Propulsion Laboratory, California Institute of Technology
MS 138-308
4800 Oak Grove Drive
Pasadena, CA 91109
email: Tony.Mannucci at jpl.nasa.gov
-- 
Tony Mannucci
Supervisor, Ionospheric and Atmospheric Remote Sensing Group
  Mail-Stop 138-308B,                     Tel > (818) 354-1699
  Jet Propulsion Laboratory,              Fax > (818) 393-5115
  California Institute of Technology,     Email > Tony.Mannucci at jpl.nasa.gov
  4800 Oak Grove Drive,                   http://genesis.jpl.nasa.gov
  Pasadena, CA 91109