David Brierley observed USA 314 on 2021 Apr 29 at 00:35 UTC, running about 65 s late. This indicates that it manoeuvred sometime on Apr 28 UTC. David observed near perigee, yet the track was considerably off, even after allowing for Earth rotation. This indicates that the manoeuvre most likely occurred closer to apogee. I have derived a set of search TLEs from the following pre-manoeuvre elements: USA 314 526 X 751 km 1 48247U 21032A 21117.99623188 .00000427 00000-0 50000-4 0 06 2 48247 98.0143 231.1479 0160400 76.7889 285.1158 14.76185313 04 The search elements assume a perigee-raising manoeuvre at apogee. The analysis is based on David's observations, and a synthetic observation at the time of manoeuvre, derived from the pre-manoeuvre elements. The manoeuvre time on Apr 28 UTC, is stated on line one. 14:04:05 542 X 751 km 1 78701U 78701A 21119.01368290 .00000389 00000-0 50000-4 0 01 2 78701 98.0143 232.1615 0148769 73.5177 288.2318 14.73653414 05 Arc 20210428.59-0429.02 WRMS resid 0.079 totl 0.055 xtrk 15:41:38 545 X 751 km 1 78702U 78702A 21119.01367399 .00000383 00000-0 50000-4 0 06 2 78702 98.0143 232.1613 0146664 73.5178 288.2088 14.73195261 02 Arc 20210428.65-0429.02 WRMS resid 0.038 totl 0.023 xtrk 17:19:11 549 X 751 km 1 78703U 78703A 21119.01366114 .00000374 00000-0 50000-4 0 02 2 78703 98.0143 232.1609 0143628 73.5178 288.1756 14.72534738 01 Arc 20210428.72-0429.02 WRMS resid 0.066 totl 0.045 xtrk 18:56:44 556 X 751 km 1 78704U 78704A 21119.01364100 .00000361 00000-0 50000-4 0 03 2 78704 98.0143 232.1602 0138870 73.5179 288.1235 14.71499761 06 Arc 20210428.79-0429.02 WRMS resid 0.177 totl 0.126 xtrk The 78702 TLE seems most likely, based on residuals, but it would be prudent to begin with the 78701 TLE, which passes earlier. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Thu Apr 29 2021 - 08:02:26 UTC
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