As of 27 September 2008 (2008 272) the satellite has completed
166 exact repeat cycles and has spent over eight years on orbit since acceptance
of the satellite by the Navy and over ten years on orbit since launch.
The satellite is currently at the middle of the 167th repeat cycle -- however,
while the WVR
has been
off since September 26th 2008 and will remain off for the foreseeable future, he RA is
also turned off as of 25 Sept during the solstice period. The satellite
has been put into a asafe mode for the present because it was necessary in order to maintain the satellite electrical power
system, momentum wheels and prevent satellite resets. (Although at the request of NOAA and the scientific community, one of the two RA Cal
periods per day has been discontinued so that additional waveform data that can
be obtained over a portion of the African continent, and this is expected to
continue as long as the RA performance remains in the normal range, it is
subject to the power limitation and cycling as noted above). FWF collection over Africa
is currently inhibited even if the RA were on due to the location of the orbit passes during eclipse,
but may be reestablished when and as the system permits on an ad hoc basis; the FWF
will be omitted if there are ground system problems and/or battery
reconditioning requirements. The satellite yaw bias is being occasionally changed for
thermal control reasons on an irregular basis, but these changes should have no
effect on the users. A propulsion maneuver was performed on 08/29/08 to
maintain the ERO.
All data collected by the satellite is processed at the Payload Operations
Center (POC) which is located at NAVOCEANO. The resultant Satellite Data
Records (SDRs) are sent to the Altimeter Data Fusion Center (ADFC) which is also
located at NAVOCEANO to be converted into the NGDRs. The Navy uses data
from the GFO Doppler beacons to produce the OpOrbits for its Operational Navy
Geophysical Data Records (NGDR-Os), and is using NASA generated Medium Laser
orbit data to generate the NGDR-Ms. The International Laser
Ranging Service (ILRS) provides tracking from its global network of laser
ranging stations to support the project. For additional details on ILRS, go to
For those who are not part of DoD: All GFO altimetry data has been authorized for unconditional (and unclassified) release by SPAWAR. Hence all GFO data (SDRs, GDRs and raw data over some ice areas) is being forwarded to NOAA (and NASA) for distribution and use by the civilian community. NOAA also uses the SDRs along with the Medium Laser orbit data from NASA to produce an independent set of GDRs known as the IGDRs. For non-DoD users, NOAA is the formal point of contact for data dissemination. If you are not part of DoD and wish access to GFO data, please contact John Lillibridge.
GFO satellite and ground system conditions and performance will be posted for external use on this page and its hyperlinks. The nominal ERO orbit parameters are:
| Semi Major Axis |
|
| Eccentricity |
|
| Inclination |
|
| Argument of Perigee |
|