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Please see the message from GeoEye (below) regarding OV-2 telemetry. At the first GAC scene of 2008, the spacecraft telemetry were found to be invalid, and the problem has not been corrected. This is affecting data processing because there are no valid GPS or attitude data to use for navigation. Efforts are underway at the SeaWiFS Project to reprocess the data, however, navigation will be substantially degraded because of the lack of attitude knowledge, and there does not appear to be any possibility of recovering this.
Updated information will be provided as it becomes available.
At year rollover, OV-2 began to experience a telemetry collection anomaly. Imagery looked okay, however the ancillary telemetry was invalid. A GIM hard boot did NOT remedy the anomaly. Loads are on board through DAY 005. Imaging will continue.
The OV-2 spacecraft was commanded into Safe Haven last night, and the SeaWiFS instrument was powered off and stowed, as GeoEye continues to investigate the loss of GPS and attitude data in the spacecraft telemetry.
Updates will be provided as they become available.
good morning, as of friday morning, seawifs is still in a commanded safe haven condition with all systems healthy. analysis of the available telemetry data has pointed to a potential source of the initial anomaly and a set of diagnostic and subsequent corrective actions are being developed. extra care is being taken to make sure that the solution that is ultimately implemented is the best one for the long-term rather than just a quick fix since we all hope to get many more years of valuable data out of this remarkable little spacecraft. the important thing to remember is that the initial problem appears to be the result of an onboard "hiccup" in the software which may have had an impact on the handling on the stored attitude control telemetry on the spacecraft and NOT a hardware failure on either the spacecraft or the seawifs instrument. the fact that the spacecraft and instrument were still performing exactly as they were supposed to even after the event and that the only indication of a problem was the absence of the telemetry information that was needed for subsequent processing of the data is a very good sign, at least to these non-engineer's mind. my hope is that we will have a better sense of the path ahead and the schedule to accomplish it by early next week. i will keep everyone posted as new information becomes available. regards for now, gene
"On January 1, 2008, beginning with OrbView-2's first imagery collection of the New Year, ancillary data associated with the imagery such as GPS and satellite attitude information stopped being included in the downlink.
As a result the imagery data cannot be geo-positioned, rendering it unusable for scientific research purposes. OrbView-2 has been removed from imaging operations for troubleshooting and diagnostics.
GeoEye remains in daily communication with OrbView-2, the satellite is in a safe condition, and we are optimistic regarding returning OrbView-2 to service.
We have investigated the performance observations and have established a resolution plan. This process, while time-consuming, has been performed using the diligence and thoroughness necessary with an aging satellite. We are finalizing the specifics of that plan to ensure that our future actions are well-developed to restore the OrbView-2 satellite into operations supporting the mission of the ocean color community with minimal risk.
We anticipate resolving this issue within the next several days, and will let you know as soon as the status changes."
here is the latest information from geoeye regarding the status for the planned restoration of routine seawifs imaging operations. hopefully, we'll have some specific and positive news to pass along next week. a large, collective crossing of fingers would be most appreciated. regards, gene
Dear OrbView-2 SeaWiFS Users,
GeoEye remains in daily communication with OrbView-2, the satellite and SeaWiFS sensor are in a safe condition, and we continue to be optimistic regarding returning OrbView-2 to service.
We continue to make progress on finalizing a recovery plan and will advise when there is a change in operational status.
The following is an update on the status of SeaWiFS from GeoEye.
February 27th, 2008 03:26 EST:
I am happy to report we successfully switched to SCC-2 on OV-2 during our 1st contact this evening. On the 2nd contact we performed the GPS receiver commanding. Everything looks nominal except for a few callback "odditities" which we need to investigate further Wednesday morning. We are now on SCC-2 and it is functional with a date of 1/1/1994.
On our 1st daytime contact on 2/27/08, we'll assess the GPS receiver status as well as review the entire spacecraft telemetry. However, as of right now, Phase 1 of our SCC Switch and recovery as documented in our SCC Switch procedure, is completed. We just need to see what clean up commanding may be necessary.
good evening, i am very happy to be able to report that as of late this afternoon, the geoeye ground controllers commanded seawifs to resume routine imaging operations and the first hrpt pass over the united states west coast has been received and looks good. the real test will be tonight at which time we hope to receive the first s-band downlink containing the first complete orbits of data since the beginning of the new year. once that pass is received and processed successfully, i think that we can all breathe a collective sigh of relief. thanks for hanging with us during this long, difficult, and at times nerve wracking experience. regards, gene
folks, just a quick note to say that seawifs decided that it wasn't quite ready to come out of early retirement and went out of imaging mode soon after the successful data downlink that i reported yesterday morning. the good news is that the source of this anomaly is understood and corrective actions are currently underway. just make sure that your seatbelts are fastened and stay in your seats because the roller coaster ride isn't quite over yet. will keep you posted as information becomes available. regards, gene
Update as of 17 March 2008: Work continues on returning SeaWiFS to full imaging mode although a target date for that to happen has not been established. At this time the spacecraft and instrument are fine and a series of table updates to the onboard software are being carried out to restore all the parameters to pre-anomaly values. Once that has been done and verified, I would anticipate that a schedule for resumption of imaging will be decided upon. Will keep you posted as new developments warrant. Regards, gene
Update as of 27 March 2008: Work continues on returning SeaWiFS to full imaging mode although a target date for that to happen has not been established. At this time the spacecraft and instrument are fine, the spacecraft power system is normal, GPS tracking has been restored and a series of table updates to the onboard software are being carried out to restore all the parameters to pre-anomaly values. As yet, however, there is no definitive schedule that has been provided for resumption of imaging. Non-critical updates will be posted to the Ocean Color Announcements section on the OceanColor forum as they become available at: