image file: Starlink-from-Northern-Europe.png ________________________________ Da: Seesat-l <seesat-l-bounces+joematara=hotmail.com_at_satobs.org> per conto di Giuseppe via Seesat-l <seesat-l_at_satobs.org> Inviato: domenica 26 maggio 2019 05:11 A: SeeSat-L_at_satobs.org Oggetto: Prediction Starlink train position One image of the video issued here http://www.satobs.org/seesat/May-2019/0234.html has been uploaded in Miscellanea folder of my GitHub repo https://github.com/sunrise125/Satellites-Orbits/find/master where the red marked satellite is trivial, just to figure out one of the sixty bodies. By introducing DateTime&Location data to the python code written below, along with the TLE elements taken from http://www.satobs.org/seesat/May-2019/0207.html we obtain such results: ----------------------------------------- Sat Name = Starlink Train Sat Epoch= 2019-05-24 22:56:05.819423 Sat Numb = 74001 Prediction date: 2019 5 25 Prediction time: 23 50 43 UTC Observer location: Lambda= 4.497 deg Phi= 52.1601 deg H= 4.0 m Azimuth : -96.35896 deg Elevation: 12.74073 deg Distance : 1408.534 km ------------------------------------------ They seem acceptable, maybe elevation appear a bit low. Nevertheless the accuracy can be enhanced when orbital elements refer to a single sat. Cheers, Giuseppe # ---- azel_TLE.py ---------- May.25, 2019 ------ # Azimuth, elevation, distance froma TLE's elements # Source: https://bwinkel.github.io/pycraf/satellite/index.html import datetime import numpy as np from astropy.coordinates import EarthLocation from astropy import time from pycraf import satellite # -------- 3-line TLE elements input ------------- tle_string = '''Starlink Train 1 74001U 19644A 19144.95562291 .00000000 00000-0 50000-4 0 06 2 74001 53.0084 171.3414 0001000 0.0000 72.1720 15.40507866 07''' satname, sat = satellite.get_sat(tle_string) print ('\n Sat Name = ', satname,'\n Sat Epoch= ', sat.epoch, '\n Sat Numb = ', sat.satnum) # Datetime input year=2019; month=5; day=25; utch=23; utcm=50; utcs=43 print ('\n Prediction date: ', year, month, day ) print (' Prediction time: ', utch, utcm, utcs, ' UTC' ) dt = datetime.datetime(year, month, day, utch, utcm, utcs) obstime = time.Time(dt) # define observer location Lambda=4.4970; Phi=52.1601; H=4.0 location = EarthLocation(Lambda, Phi, H) # create a SatelliteObserver instance sat_obs = satellite.SatelliteObserver(location) # az, el, dist = sat_obs.azel_from_sat(tle_string, obstime) print('\n Observer location: Lambda=', Lambda, 'deg Phi=', Phi, 'deg H=', H,' m') print(' Azimuth : {:.5f}'.format(az)) print(' Elevation: {:.5f}'.format(el)) print(' Distance : {:.3f}'.format(dist)) # EOF azel_TLE.py ---------- _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Sun May 26 2019 - 00:24:17 UTC
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