Actualités
[Jason-1] Low tracking performance on the star trackers
Following the Jason-1 maneuvers on 19-July-2010, the star tracker performance is once again degraded.
March 2010: degradation of the on-orbit performance of the star trackers and gyro wheels. The most immediate impact has been on the Jason-1 Near-Real-Time OSDR products, because the altimeter retracking algorithm used for the OSDR products requires off-nadir angles less than 0.3 degrees.
July 2010: new degradation on the star tracker performance following the Jason-1 maneuvers on 19-July-2010. This loss of star tracking generates significant off-nadir pointing in NRT products and frequent altimeter loss of lock and resets that affect all science products.
Since the yaw flip performed on Sunday, 25-July-2010, the situation has continued to degrade and the Jason-1 Poseidon altimeter has exhibited very poor performance which has impacted the availability of OSDR, IGDR and GDR products.
It is expected that the star tracker and Poseidon altimeter performance will improve after Saturday, 31-July-2001, when Jason-1 returns to a yaw-steering configuration.
Jason-1 Science Cycles 315 and 316 are also being impacted by ongoing hydrazine depletion maneuvers which are scheduled to conclude on Wednesday, 04-August-2010.
The Jason-1 JPL and Cnes Project Managers will provide an update as soon as the situation improves.
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