----- Original Message ----- ... > If its not working, its orientation is unknown. In a lot > of satellites solar panels are kept pointing at the sun, which > means ground observers cant get sunglints. Iridiums are an exception > because of operational need. Rob Matson's IRIDFLAR programme > gives solar panel flare predictions as well as the MMA sunglints > that HA predicts. Additionally, if a glinting satellite, that is no longer controlled, has acquired a stable rotation, and does not have as many non-aligned surfaces as an Iridium, its rotation can be computed and glint directions predicted. A few observations of its glint RA/Decs to a degree or better accuracy (or date+time to matching accuracy) can be sufficient, if in various directions, and over a time period while atmosphere and magnetic fields don't alter the axis considerably. For defunct geosynch comsats, this means that observations can be accumulated over a period up to one more years, while the Sun's apparent motion contributes to spreading the observation geometry. For LEO's the period must be considerably shorter. ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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