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`.
"""
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/except is not well supported by Numba
if (len(line) >= 64 and line.startswith('1 ') and line[8] == ' '
and line[23] == '.' and line[32] == ' ' and line[34] == '.'
and line[43] == ' ' and line[52] == ' ' and line[61] == ' '
and line[63] == ' '):
_saved_satnum = satrec.satnum = int(line[2:7])
# classification = line[7] or 'U'
# intldesg = line[9:17]
two_digit_year = int(line[18:20])
satrec.epochdays = float(line[20:32])
satrec.ndot = float(line[33:43])
satrec.nddot = float(line[44] + '.' + line[45:50])
nexp = int(line[50:52])
satrec.bstar = float(line[53] + '.' + line[54:59])
ibexp = int(line[59:61])
# numb = int(line[62])
# elnum = int(line[64:68])
else:
raise ValueError(error_message.format(1, LINE1, line))
line = longstr2.rstrip()
if (len(line) >= 69 and line.startswith('2 ') and line[7] == ' '
and line[11] == '.' and line[16] == ' ' and line[20] == '.'
and line[25] == ' ' and line[33] == ' ' and line[37] == '.'
and line[42] == ' ' and line[46] == '.' and line[51] == ' '):
satrec.satnum = int(line[2:7])
if _saved_satnum != satrec.satnum:
raise ValueError('Object numbers in lines 1 and 2 do not match')
satrec.inclo = float(line[8:16])
satrec.nodeo = float(line[17:25])
satrec.ecco = float('0.' + line[26:33].replace(' ', '0'))
satrec.argpo = float(line[34:42])
satrec.mo = float(line[43:51])
satrec.no = float(line[52:63])
#revnum = line[63:68]
#except (AssertionError, IndexError, ValueError):
else:
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, afspc_mode, 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, opsmode='i', satrec=None):
"""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 "opsmode" mode, then set `opsmode` to `a`.
"""
deg2rad = pi / 180.0
# 0.0174532925199433
xpdotp = 1440.0 / (2.0 * pi)
# 229.1831180523293
# For compatibility with our 1.x API, build an old Satellite object
# if the caller fails to supply a satrec. In that case we perform
# the necessary import here to avoid an import loop.
if satrec is None:
from sgp4.model import Satellite
satrec = Satellite()
satrec.error = 0
satrec.whichconst = whichconst # Python extension: remembers its consts
line = longstr1.rstrip()
if (len(line) >= 64 and line.startswith('1 ') and line[8] == ' '
and line[23] == '.' and line[32] == ' ' and line[34] == '.'
and line[43] == ' ' and line[52] == ' ' and line[61] == ' '
and line[63] == ' '):
_saved_satnum = satrec.satnum = int(line[2:7])
satrec.classification = line[7] or 'U'
satrec.intldesg = line[9:17].rstrip()
two_digit_year = int(line[18:20])
satrec.epochdays = float(line[20:32])
satrec.ndot = float(line[33:43])
satrec.nddot = float(line[44] + '.' + line[45:50])
nexp = int(line[50:52])
satrec.bstar = float(line[53] + '.' + line[54:59])
ibexp = int(line[59:61])
satrec.ephtype = line[62]
satrec.elnum = int(line[64:68])
else:
raise ValueError(error_message.format(1, LINE1, line))
line = longstr2.rstrip()
if (len(line) >= 69 and line.startswith('2 ') and line[7] == ' '
and line[11] == '.' and line[16] == ' ' and line[20] == '.'
and line[25] == ' ' and line[33] == ' ' and line[37] == '.'
and line[42] == ' ' and line[46] == '.' and line[51] == ' '):
satrec.satnum = int(line[2:7])
if _saved_satnum != satrec.satnum:
raise ValueError('Object numbers in lines 1 and 2 do not match')
satrec.inclo = float(line[8:16])
satrec.nodeo = float(line[17:25])
satrec.ecco = float('0.' + line[26:33].replace(' ', '0'))
satrec.argpo = float(line[34:42])
satrec.mo = float(line[43:51])
satrec.no_kozai = float(line[52:63])
satrec.revnum = line[63:68]
#except (AssertionError, IndexError, ValueError):
else:
raise ValueError(error_message.format(2, LINE2, line))
# ---- find no, ndot, nddot ----
satrec.no_kozai = satrec.no_kozai / xpdotp
# rad/min
satrec.nddot = satrec.nddot * pow(10.0, nexp)
satrec.bstar = satrec.bstar * pow(10.0, ibexp)
# ---- convert to sgp4 units ----
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
"""
// ----------------------------------------------------------------
// 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)
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
def kep_to_sat(kep,
epoch,
bstar=0.21109E-4,
whichconst=wgs72,
afspc_mode=False):
"""kep_to_sat(kep,epoch,bstar=0.21109E-4,whichconst=wgs72,afspc_mode=False)
Converts a set of keplerian elements into a Satellite object.
Args:
kep(1x6 numpy array): the osculating keplerian elements at epoch
epoch(float): the epoch
bstar(float): bstar drag coefficient
whichconst(float): gravity model. refer pypi sgp4 documentation
afspc_mode(boolean): refer pypi sgp4 documentation
Returns:
Satellite object: an sgp4 satellite object encapsulating the arguments
"""
deg2rad = np.pi / 180.0
# 0.0174532925199433
xpdotp = 1440.0 / (2.0 * np.pi)
# 229.1831180523293
tumin = whichconst.tumin
satrec = Satellite()
satrec.error = 0
satrec.whichconst = whichconst # Python extension: remembers its consts
satrec.satnum = 0
dt_obj = datetime.utcfromtimestamp(epoch)
t_obj = dt_obj.timetuple()
satrec.epochdays = (t_obj.tm_yday + t_obj.tm_hour / 24 +
t_obj.tm_min / 1440 + t_obj.tm_sec / 86400)
satrec.ndot = 0
satrec.nddot = 0
satrec.bstar = bstar
satrec.inclo = kep[2]
satrec.nodeo = kep[4]
satrec.ecco = kep[1]
satrec.argpo = kep[3]
satrec.mo = __true_to_mean(kep[5], kep[1])
satrec.no = 86400 / (2 * np.pi * (kep[0]**3 / 398600.4405)**0.5)
satrec.no = satrec.no / xpdotp
# rad/min
satrec.a = pow(satrec.no * tumin, (-2.0 / 3.0))
# ---- 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
satrec.epochyr = dt_obj.year
satrec.jdsatepoch = epoch / 86400.0 + 2440587.5
satrec.epoch = dt_obj
# ---------------- initialize the orbit at sgp4epoch -------------------
sgp4init(whichconst, afspc_mode, satrec.satnum,
satrec.jdsatepoch - 2433281.5, satrec.bstar, satrec.ecco,
satrec.argpo, satrec.inclo, satrec.mo, satrec.no, satrec.nodeo,
satrec)
return satrec
