def propagate(self, year, month=1, day=1, hour=0, minute=0, second=0.0): """Return a position and velocity vector for a given date and time.""" j = jday(year, month, day, hour, minute, second) m = (j - self.jdsatepoch) * minutes_per_day r, v = sgp4(self, m) return r, v
def twoline2rv(longstr1, longstr2, whichconst, afspc_mode=False): """Return a Satellite imported from two lines of TLE data. Provide the two TLE lines as strings `longstr1` and `longstr2`, and select which standard set of gravitational constants you want by providing `gravity_constants`: `sgp4.earth_gravity.wgs72` - Standard WGS 72 model `sgp4.earth_gravity.wgs84` - More recent WGS 84 model `sgp4.earth_gravity.wgs72old` - Legacy support for old SGP4 behavior Normally, computations are made using various recent improvements to the algorithm. If you want to turn some of these off and go back into "afspc" mode, then set `afspc_mode` to `True`. """ opsmode = 'a' if afspc_mode else 'i' deg2rad = pi / 180.0; # 0.0174532925199433 xpdotp = 1440.0 / (2.0 *pi); # 229.1831180523293 tumin = whichconst.tumin satrec = Satellite() satrec.error = 0; satrec.whichconst = whichconst # Python extension: remembers its consts line = longstr1.rstrip() try: assert line.startswith('1 ') satrec.satnum = int(line[2:7]) # classification = line[7] or 'U' assert line[8] == ' ' # intldesg = line[9:17] two_digit_year = int(line[18:20]) assert line[23] == '.' satrec.epochdays = float(line[20:32]) assert line[32] == ' ' assert line[34] == '.' satrec.ndot = float(line[33:43]) assert line[43] == ' ' satrec.nddot = float(line[44] + '.' + line[45:50]) nexp = int(line[50:52]) assert line[52] == ' ' satrec.bstar = float(line[53] + '.' + line[54:59]) ibexp = int(line[59:61]) assert line[61] == ' ' assert line[63] == ' ' # numb = int(line[62]) # elnum = int(line[64:68]) except (AssertionError, IndexError, ValueError): raise ValueError(error_message.format(1, LINE1, line)) line = longstr2.rstrip() try: assert line.startswith('2 ') satrec.satnum = int(line[2:7]) # TODO: check it matches line 1? assert line[7] == ' ' assert line[11] == '.' satrec.inclo = float(line[8:16]) assert line[16] == ' ' assert line[20] == '.' satrec.nodeo = float(line[17:25]) assert line[25] == ' ' satrec.ecco = float('0.' + line[26:33].replace(' ', '0')) assert line[33] == ' ' assert line[37] == '.' satrec.argpo = float(line[34:42]) assert line[42] == ' ' assert line[46] == '.' satrec.mo = float(line[43:51]) assert line[51] == ' ' satrec.no = float(line[52:63]) #revnum = line[63:68] except (AssertionError, IndexError, ValueError): raise ValueError(error_message.format(2, LINE2, line)) # ---- find no, ndot, nddot ---- satrec.no = satrec.no / xpdotp; # rad/min satrec.nddot= satrec.nddot * pow(10.0, nexp); satrec.bstar= satrec.bstar * pow(10.0, ibexp); # ---- convert to sgp4 units ---- satrec.a = pow( satrec.no*tumin , (-2.0/3.0) ); satrec.ndot = satrec.ndot / (xpdotp*1440.0); # ? * minperday satrec.nddot= satrec.nddot / (xpdotp*1440.0*1440); # ---- find standard orbital elements ---- satrec.inclo = satrec.inclo * deg2rad; satrec.nodeo = satrec.nodeo * deg2rad; satrec.argpo = satrec.argpo * deg2rad; satrec.mo = satrec.mo * deg2rad; satrec.alta = satrec.a*(1.0 + satrec.ecco) - 1.0; satrec.altp = satrec.a*(1.0 - satrec.ecco) - 1.0; """ // ---------------------------------------------------------------- // find sgp4epoch time of element set // remember that sgp4 uses units of days from 0 jan 1950 (sgp4epoch) // and minutes from the epoch (time) // ---------------------------------------------------------------- // ---------------- temp fix for years from 1957-2056 ------------------- // --------- correct fix will occur when year is 4-digit in tle --------- """ if two_digit_year < 57: year = two_digit_year + 2000; else: year = two_digit_year + 1900; mon,day,hr,minute,sec = days2mdhms(year, satrec.epochdays); sec_whole, sec_fraction = divmod(sec, 1.0) satrec.epochyr = year satrec.jdsatepoch = jday(year,mon,day,hr,minute,sec); satrec.epoch = datetime(year, mon, day, hr, minute, int(sec_whole), int(sec_fraction * 1000000.0 // 1.0)) # ---------------- initialize the orbit at sgp4epoch ------------------- sgp4init(whichconst, opsmode, satrec.satnum, satrec.jdsatepoch-2433281.5, satrec.bstar, satrec.ecco, satrec.argpo, satrec.inclo, satrec.mo, satrec.no, satrec.nodeo, satrec) return satrec
def twoline2rv(longstr1, longstr2, whichconst, afspc_mode=False): """Return a Satellite imported from two lines of TLE data. Provide the two TLE lines as strings `longstr1` and `longstr2`, and select which standard set of gravitational constants you want by providing `gravity_constants`: `sgp4.earth_gravity.wgs72` - Standard WGS 72 model `sgp4.earth_gravity.wgs84` - More recent WGS 84 model `sgp4.earth_gravity.wgs72old` - Legacy support for old SGP4 behavior Normally, computations are made using various recent improvements to the algorithm. If you want to turn some of these off and go back into "afspc" mode, then set `afspc_mode` to `True`. """ opsmode = 'a' if afspc_mode else 'i' deg2rad = pi / 180.0; # 0.0174532925199433 xpdotp = 1440.0 / (2.0 *pi); # 229.1831180523293 tumin = whichconst.tumin satrec = Satellite() satrec.error = 0; satrec.whichconst = whichconst # Python extension: remembers its consts line = longstr1.rstrip() try: assert line.startswith('1 ') satrec.satnum = int(line[2:7]) # classification = line[7] or 'U' assert line[8] == ' ' # intldesg = line[9:17] two_digit_year = int(line[18:20]) assert line[23] == '.' satrec.epochdays = float(line[20:32]) assert line[32] == ' ' assert line[34] == '.' satrec.ndot = float(line[33:43]) assert line[43] == ' ' satrec.nddot = float(line[44] + '.' + line[45:50]) nexp = int(line[50:52]) assert line[52] == ' ' satrec.bstar = float(line[53] + '.' + line[54:59]) ibexp = int(line[59:61]) assert line[61] == ' ' assert line[63] == ' ' # numb = int(line[62]) # elnum = int(line[64:68]) except (AssertionError, IndexError, ValueError): raise ValueError(error_message.format(1, LINE1, line)) line = longstr2.rstrip() try: assert line.startswith('2 ') satrec.satnum = int(line[2:7]) # TODO: check it matches line 1? assert line[7] == ' ' assert line[11] == '.' satrec.inclo = float(line[8:16]) assert line[16] == ' ' assert line[20] == '.' satrec.nodeo = float(line[17:25]) assert line[25] == ' ' satrec.ecco = float('0.' + line[26:33].replace(' ', '0')) assert line[33] == ' ' assert line[37] == '.' satrec.argpo = float(line[34:42]) assert line[42] == ' ' assert line[46] == '.' satrec.mo = float(line[43:51]) assert line[51] == ' ' satrec.no = float(line[52:63]) #revnum = line[63:68] except (AssertionError, IndexError, ValueError): raise ValueError(error_message.format(2, LINE2, line)) # ---- find no, ndot, nddot ---- satrec.no = satrec.no / xpdotp; # rad/min satrec.nddot= satrec.nddot * pow(10.0, nexp); satrec.bstar= satrec.bstar * pow(10.0, ibexp); # ---- convert to sgp4 units ---- satrec.a = pow( satrec.no*tumin , (-2.0/3.0) ); satrec.ndot = satrec.ndot / (xpdotp*1440.0); # ? * minperday satrec.nddot= satrec.nddot / (xpdotp*1440.0*1440); # ---- find standard orbital elements ---- satrec.inclo = satrec.inclo * deg2rad; satrec.nodeo = satrec.nodeo * deg2rad; satrec.argpo = satrec.argpo * deg2rad; satrec.mo = satrec.mo * deg2rad; satrec.alta = satrec.a*(1.0 + satrec.ecco) - 1.0; satrec.altp = satrec.a*(1.0 - satrec.ecco) - 1.0; """ // ---------------------------------------------------------------- // find sgp4epoch time of element set // remember that sgp4 uses units of days from 0 jan 1950 (sgp4epoch) // and minutes from the epoch (time) // ---------------------------------------------------------------- // ---------------- temp fix for years from 1957-2056 ------------------- // --------- correct fix will occur when year is 4-digit in tle --------- """ if two_digit_year < 57: year = two_digit_year + 2000; else: year = two_digit_year + 1900; mon,day,hr,minute,sec = days2mdhms(year, satrec.epochdays); sec_whole, sec_fraction = divmod(sec, 1.0) satrec.epochyr = year satrec.jdsatepoch = jday(year,mon,day,hr,minute,sec); satrec.epoch = datetime(year, mon, day, hr, minute, int(sec_whole), int(sec_fraction * 1000000.0 // 1.0)) # ---------------- initialize the orbit at sgp4epoch ------------------- sgp4init(whichconst, opsmode, satrec.satnum, satrec.jdsatepoch-2433281.5, satrec.bstar, satrec.ecco, satrec.argpo, satrec.inclo, satrec.mo, satrec.no, satrec.nodeo, satrec) print satrec return satrec