How to use sgp4 - 10 common examples

// 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);
    try:
        satrec.epoch = datetime(year, mon, day, hr, minute, int(sec_whole),
                                int(sec_fraction * 1000000.0 // 1.0))
    except ValueError:
        # Sometimes a TLE says something like "2019 + 366.82137887 days"
        # which would be December 32nd which causes a ValueError.
        year, mon, day, hr, minute, sec = invjday(satrec.jdsatepoch)
        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.ndot, satrec.nddot, satrec.ecco, satrec.argpo, satrec.inclo, satrec.mo,
             satrec.no_kozai, satrec.nodeo, satrec)

    return satrec

sec_whole, sec_fraction = divmod(sec, 1.0)

    satrec.epochyr = year
    satrec.jdsatepoch = jday(year,mon,day,hr,minute,sec);
    try:
        satrec.epoch = datetime(year, mon, day, hr, minute, int(sec_whole),
                                int(sec_fraction * 1000000.0 // 1.0))
    except ValueError:
        # Sometimes a TLE says something like "2019 + 366.82137887 days"
        # which would be December 32nd which causes a ValueError.
        year, mon, day, hr, minute, sec = invjday(satrec.jdsatepoch)
        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.ndot, satrec.nddot, satrec.ecco, satrec.argpo, satrec.inclo, satrec.mo,
             satrec.no_kozai, satrec.nodeo, satrec)

    return satrec

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);
    try:
        satrec.epoch = datetime(year, mon, day, hr, minute, int(sec_whole),
                                int(sec_fraction * 1000000.0 // 1.0))
    except ValueError:
        # Sometimes a TLE says something like "2019 + 366.82137887 days"
        # which would be December 32nd which causes a ValueError.
        year, mon, day, hr, minute, sec = invjday(satrec.jdsatepoch)
        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.ndot, satrec.nddot, satrec.ecco, satrec.argpo, satrec.inclo, satrec.mo,
             satrec.no_kozai, satrec.nodeo, satrec)

    return satrec

@lru_cache(maxsize=365)
def jday_day(year, mon, day):
    return (367.0 * year -
            7.0 * (year + ((mon + 9.0) // 12.0)) * 0.25 // 1.0 +
            275.0 * mon // 9.0 +
            day + 1721013.5)


def jday(year, mon, day, hr, minute, sec):
    base = jday_day(year, mon, day)
    return base + ((sec / 60.0 + minute) / 60.0 + hr) / 24.0


ext.jday = jday
model.jday = jday

# finish hack zone


class HighAccuracyTLEPredictor(CartesianPredictor):
    """A pass predictor with high accuracy on estimations"""

    @reify
    def tle(self):
        return self.source.get_tle(self.sate_id, dt.datetime.utcnow())

    @reify
    def _propagator(self):
        tle_line_1, tle_line_2 = self.tle.lines
        return twoline2rv(tle_line_1, tle_line_2, wgs84)

baseline = Timer(lambda: tsp.find_rms_inline_scalar(satnew, rd, ll, odata)).timeit(number=num)
    print("find_rms_inline_scalar:      {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: tsp.find_rms_inline_scalar(satnew, rd, ll, odata)).timeit(number = num)) ))
    print("find_rms:                    {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: find_rms(satnew, rd, ll, odata)).timeit(number = num)) ))
    print("find_rms_old:                {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: tsp.find_rms_old(satold, rd, ll, odata)).timeit(number = num)) ))
    print("find_rmspy:                  {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: tsp.find_rmspy(satold, rd, ll, odata)).timeit(number = num)) ))
else:
    print("find_rms:                    {:.6f}".format( Timer(lambda: find_rms(satnew, rd, ll, odata)).timeit(number = num)) )

print()
find_rms_inline_baseline = baseline

tsince = (60 + satnew.jdsatepoch) * 1440.0 # time since epoch in minutes
(jd, fr) = divmod(satnew.jdsatepoch,1)
satnew.sgp4(jd, fr)

satrec3 = Satrec()
satrec3_jdsatepoch  = 2451723.28495062
satrec3.sgp4init(WGS72, 'i', satnum, satrec3_jdsatepoch-2433281.5, bstar, 
                ndot, nddot, ecco, argpo, inclo, mo, no_kozai, nodeo)

print("Single element SGP4")
baseline = Timer(lambda: satrec3.sgp4(jd,fr)).timeit(number = num)
print("sgp4_cpp(1):                 {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: satrec3.sgp4(jd,fr)).timeit(number = num)) ))
print("sgp4_py:                     {:.6f} {:.2f}x".format( *tac(baseline, Timer(lambda: sgp4(satold, tsince)).timeit(number = num)) ))
print()

print("Vector element SGP4 vs scalar loop of same #")
sats = []
sats.append(satnew)
a = SatrecArray(sats)

for j in range(len(odata)):

def test_satrec_initialized_with_sgp4init_in_afspc_mode():
    sat = Satrec()
    sat.sgp4init(
        WGS72,
        'a',
        VANGUARD_ATTRS['satnum'],
        VANGUARD_EPOCH,
        *sgp4init_args(VANGUARD_ATTRS)
    )
    assertEqual(sat.operationmode, 'a')

bmax = 1.1*b
bmin = 0.9*b
bstep = (bmax-bmin)/20.0

satnum   = 5
bstar    = 2.8098e-05
ndot     = 6.96919666594958e-13
nddot    = 0.0
ecco     = 0.1859667
argpo    = 5.790416027488515
inclo    = 0.5980929187319208
mo       = 0.3373093125574321
no_kozai = 0.04722944544077857
nodeo    = 6.08638547138321

sat2 = Satrec()
sat2_jdsatepoch  = 2451723.28495062

sat2.sgp4init(WGS72, 'i', satnum, sat2_jdsatepoch, bstar, ndot, nddot,
              ecco, argpo, inclo, mo, no_kozai, nodeo)


# Vectorized Python-SGP4 array initialization
jd = np.linspace(2451723, 2451723+900, 100)
fr = np.zeros((jd.shape[0],))
rv_template = np.zeros((1, len(jd), 3), dtype='double')

print()
np_zeros_template = np.zeros((1,10,3), dtype='double')
np_empty_template = np.empty((1,10,3), dtype='double')

def tac(baseline, time):

def test_all_three_gravity_models_with_sgp4init():
    # Gravity models specified with sgp4init() should also change the
    # positions generated.

    sat = Satrec()
    args = sgp4init_args(VANGUARD_ATTRS)

    sat.sgp4init(WGS72OLD, 'i', VANGUARD_ATTRS['satnum'], VANGUARD_EPOCH, *args)
    assert_wgs72old(sat)

    sat.sgp4init(WGS72, 'i', VANGUARD_ATTRS['satnum'], VANGUARD_EPOCH, *args)
    assert_wgs72(sat)

    sat.sgp4init(WGS84, 'i', VANGUARD_ATTRS['satnum'], VANGUARD_EPOCH, *args)
    assert_wgs84(sat)

def test_legacy_initialized_with_sgp4init():
    sat = model.Satellite()
    sgp4init(
        wgs72, 'i', VANGUARD_ATTRS['satnum'], VANGUARD_EPOCH,
        *sgp4init_args(VANGUARD_ATTRS) + (sat,)
    )
    verify_vanguard_1(sat, legacy=True)

def test_legacy_initialized_with_sgp4init():
    sat = model.Satellite()
    sgp4init(
        wgs72, 'i', VANGUARD_ATTRS['satnum'], VANGUARD_EPOCH,
        *sgp4init_args(VANGUARD_ATTRS) + (sat,)
    )
    verify_vanguard_1(sat, legacy=True)