Hi everyone.... Earlier in the year I captured three geo movers on film. Two were unid , but the third I actually targeted , so we know 100% that it was. (Eut W3A ) Given that we have one "control" video..... , W3A , we can compare the movement to the other two in order to possibly ascertain if the unids were in controlled drift , or graveyard orbit . Fortunately , when capturing the three movers , I used 10 sec exposures so I can compare like for like. I took four consecutive frames from each capture , all at 640 x 480 .... applied a simple grid to each , then cropped out the movement over the 40 sec period. The grid square used gives about 5 km per square in the arc. Interestingly each of the movers , including the control item , are drfiting at about the same speed , relative to birds in geo orbit...and in the same direction ... west to east. It equates to about 7.5km / minute.....450 km / hour ( relative to stable geosats ) At the time it was thought that the two unids were possibly in graveyard orbit or possibly debris (although they were not flashing) However , my findings point to the possibility that these were in fact in conrolled drift , like W3A Keps for W3A during the drift period indicate it was about 50 km below the geo belt. At this point , I get lost with the maths...yet again ;O) If my relative velocity of 450 km / hour is right , does this compute to an approximate orbit of 50 km or so below the geo belt? Also , does anyone know what the tolerance is ( in km ) for a geosat to remain stable in orbit ? (I'm assuming that different topgraphy below their lots will have a marginal affect on orbital height ) Any thoughts ? Thanks , John. ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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