S-band radio tracking over 6 passes by Tomi Simola and myself indicate the NROL-91 payload's (USA 338) mean motion is near 15.588 revs/day. Independent radio tracking by Nico Janssen confirms this. Alternating the fitting of the 99691 optical observations to constrain all orbital parameters while using the mean motion from fits to the S-band radio observations yields this search orbit. Here the eccentricity and argument of perigee are adjusted to improve the fit of the optical observations for the fixed mean motion. Treat this orbit as an estimate as the uncertainties from this fitting approach are hard to quantify, and USA 338 may have maneuvered in the interim. 1 99691U 22268.17891177 .00000000 00000-0 50000-4 0 07 2 99691 73.5839 52.4723 0036737 359.3711 53.6976 15.58769192 08 # 20220925.18-20220925.18, 12 measurements, 0.057 deg rms Happy hunting and clear skies! Cees _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Sun Sep 25 2022 - 10:35:49 UTC
This archive was generated by hypermail 2.4.0 : Sun Sep 25 2022 - 15:35:49 UTC