def calcLong_3(catalog, number=0):
''' Возвращает три массива орбитальных ошибок "длинных интервалов"
'''
time = []
sig1 = []
sig2 = []
sig3 = []
line1 = catalog.line1[number]
line2 = catalog.line2[number]
sat1 = twoline2rv(line1, line2, wgs72)
for numsat in range(0, len(catalog.line1)):
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat] - catalog.JD[number]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
s1, s2, s3 = orbitSigma(x1, v1, x2, v2)
time.append((catalog.JD[numsat] - catalog.JD[number]))
sig1.append(s1)
sig2.append(s2)
sig3.append(s3)
return sig1, sig2, sig3, time
def generate_satellite_output(satrec, line2):
"""Print a data line for each time in line2's start/stop/step field."""
mu = satrec.whichconst.mu
r, v = sgp4(satrec, 0.0)
if r is None:
yield '(Use previous data line)'
return
yield format_short_line(satrec, r, v)
tstart, tend, tstep = (float(field) for field in line2[69:].split())
tsince = tstart
while tsince <= tend:
if tsince == tstart == 0.0:
tsince += tstep
continue # avoid duplicating the first line
r, v = sgp4(satrec, tsince)
if r is None:
return
yield format_long_line(satrec, mu, r, v)
tsince += tstep
if tsince - tend < tstep - 1e-6: # do not miss last line!
r, v = sgp4(satrec, tend)
if r is None:
return
yield format_long_line(satrec, mu, r, v)
def calcShort_ephem(catalog, ephem):
''' Возвращает масиив ошибок по конкретному элементу орбиты
'''
time = []
sig = []
for numsat in range(0, len(catalog.line1) - 1):
# формирование массива данных рассчётов
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat1 = twoline2rv(line1, line2, wgs72)
line1 = catalog.line1[numsat + 1]
line2 = catalog.line2[numsat + 1]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat + 1] - catalog.JD[numsat]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
s = ephemSigma(x1, v1, x2, v2, ephem)
time.append((catalog.JD[numsat] - catalog.JD[0]))
sig.append(s)
return sig, time
def calcShort_R(catalog):
''' Возвращает массив полных ошибок "коротких интервалов"
'''
time = []
sig = []
for numsat in range(0, len(catalog.line1) - 1):
# формирование массива данных рассчётов
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat1 = twoline2rv(line1, line2, wgs72)
line1 = catalog.line1[numsat + 1]
line2 = catalog.line2[numsat + 1]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat + 1] - catalog.JD[numsat]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
time.append((catalog.JD[numsat] - catalog.JD[0]))
sig.append(fullSigma(x1, x2))
return sig, time
def generate_satellite_output(satrec, line2, error_list):
"""Print a data line for each time in line2's start/stop/step field."""
mu = satrec.whichconst.mu
r, v = sgp4(satrec, 0.0)
if isnan(r[0]) and isnan(r[1]) and isnan(r[2]):
error_list.append((satrec.error, satrec.error_message))
yield '(Use previous data line)'
return
yield format_short_line(satrec, r, v)
tstart, tend, tstep = (float(field) for field in line2[69:].split())
tsince = tstart
while tsince <= tend:
if tsince == tstart == 0.0:
tsince += tstep
continue # avoid duplicating the first line
r, v = sgp4(satrec, tsince)
if satrec.error:
error_list.append((satrec.error, satrec.error_message))
return
yield format_long_line(satrec, mu, r, v)
tsince += tstep
if tsince - tend < tstep - 1e-6: # do not miss last line!
r, v = sgp4(satrec, tend)
if satrec.error:
error_list.append((satrec.error, satrec.error_message))
return
yield format_long_line(satrec, mu, r, v)
def calcShort_3(catalog):
''' Возвращает три массива орбитальных ошибок "коротких интервалов"
'''
time = []
sig1 = []
sig2 = []
sig3 = []
for numsat in range(0, len(catalog.line1) - 1):
# формирование массива данных рассчётов
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat1 = twoline2rv(line1, line2, wgs72)
line1 = catalog.line1[numsat + 1]
line2 = catalog.line2[numsat + 1]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat + 1] - catalog.JD[numsat]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
s1, s2, s3 = orbitSigma(x1, v1, x2, v2)
time.append((catalog.JD[numsat] - catalog.JD[0]))
sig1.append(s1)
sig2.append(s2)
sig3.append(s3)
return sig1, sig2, sig3, time
def calcLong_ephem(catalog, ephem, number=0):
''' Возвращает массив ошибок по конкретному элементу орбиты
'''
line1 = catalog.line1[number]
line2 = catalog.line2[number]
sat1 = twoline2rv(line1, line2, wgs72)
time = []
sig = []
for numsat in range(0, len(catalog.line1)):
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat] - catalog.JD[number]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
s = ephemSigma(x1, v1, x2, v2, ephem)
time.append((catalog.JD[numsat] - catalog.JD[number]))
sig.append(s)
return sig, time
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 generate_satellite_output_vectorial(satrec, line2, error_list):
"""Print a data line for each time in line2's start/stop/step field."""
if satrec.method == 'd':
yield from generate_satellite_output(satrec, line2, error_list)
return
import numpy as np
mu = satrec.whichconst.mu
tstart, tend, tstep = (float(field) for field in line2[69:].split())
times = np.arange(tstart, tend, tstep)
if times[-1] - tend < tstep - 1e-6: # do not miss last line!
times = np.append(times, tend)
_r, _v = np.array(sgp4(satrec, times))
if _r.shape == (3, ):
if isnan(_r[0]) and isnan(_r[1]) and isnan(_r[2]):
error_list.append((satrec.error, satrec.error_message))
print(error_list)
return
for i in range(_r.shape[1]):
r = list(_r[:, i])
v = list(_v[:, i])
t = satrec.t[i]
if i == 0:
yield format_short_line(t, r, v)
else:
yield format_long_line(satrec, t, mu, r, v)
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 calcXYZ(self, name, time):
''' Вычисление прямоугольных координат.
на выходе:
-- кординаты аппарата
-- скорости
-- номер использованных эфемерид в каталоге
-- длительность экстраполяции (в минутах)
'''
# поиск ближайшего ИСЗ к этому моменту времени
d_since = 1e+10
num = -1
for i in range(0, len(self.time)):
if self.name[i].find(name) == -1: # не тот спутник, пропускаем
continue
d_day = time - self.time[i]
d_sinceNew = d_day.days * 24 * 60 + d_day.seconds / 60
if (abs(d_sinceNew) < abs(d_since)): # более свежие эфемериды
num = i
d_since = d_sinceNew
line1 = self.line1[num]
line2 = self.line2[num]
satellite = twoline2rv(line1, line2, wgs72)
# position, velocity = satellite.propagate(2016, 6, 30, 12, 0, 0)
position, velocity = sgp4(satellite, d_since)
return position, velocity, num, d_since
def _testSGP():
''' Тестируем чтение информации по ИСЗ + вычисление координат
'''
print(' ')
print('Тест SGP.')
catalog = CatalogTLE()
catalog.readTLEsat('catalogs/catalog_2016_06_30.txt', 'ISS')
catalog.status()
line1 = catalog.getLine1('ISS')
line2 = catalog.getLine2('ISS')
satellite = twoline2rv(line1, line2, wgs72)
# position, velocity = satellite.propagate(2016, 6, 30, 12, 0, 0)
position, velocity = sgp4(satellite, 10.001)
print('--- error ---')
print(satellite.error) # nonzero on error
print('--- error_message ---:')
print(satellite.error_message)
print('--- position ---')
print(position)
print('--- velocity ---')
print(velocity)
def drawEphem_allcatalog(catalog, ephem):
''' Создание графиков эволюции эфемериды на протяжении полученного каталога
catalog -- каталог ТЛЕ
ephem -- название той эфемериды, что нам надо
number -- номер данных в каталоге (по умолчанию 0)
'''
time = []
val = []
for numsat in range(0, len(catalog.line1)):
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat] - catalog.JD[0]) * 24 * 60
x1, v1 = sgp4(sat, dT)
orbit = KeplerOrbit()
orbit.xyz2ephem(x1[0], x1[1], x1[2], v1[0], v1[1], v1[2])
time.append(catalog.JD[numsat] - catalog.JD[0])
val.append(orbit.get_ephem(ephem))
plt.plot(time, val, 'r-')
plt.plot(time, val, 'k+')
plt.xlabel('Epoсh')
plt.ylabel('Ephemeris')
plt.title(catalog.name[1])
plt.grid(True)
plt.show()
def drawEphem_oneSat(catalog, ephem, dT, number=0):
''' Создание графиков эволюции эфемериды в пронозе SGP
catalog -- каталог ТЛЕ
ephem -- название той эфемериды, что нам надо
dT -- массив времён, на который строим график (в сутках)
number -- номер данных в каталоге (по умолчанию 0)
'''
line1 = catalog.line1[number]
line2 = catalog.line2[number]
sat1 = twoline2rv(line1, line2, wgs72)
time = []
val = []
for t in dT:
x1, v1 = sgp4(sat1, t / 24 / 60)
orbit = KeplerOrbit()
orbit.xyz2ephem(x1[0], x1[1], x1[2], v1[0], v1[1], v1[2])
time.append(t)
val.append(orbit.get_ephem(ephem))
sig = calcLong_ephem(catalog, ephem, number)
plt.plot(time, val, 'c-')
plt.plot(time, val, 'k+')
plt.xlabel('Epoсh (day)')
plt.ylabel('Ephemeris')
plt.title(catalog.name[1])
plt.grid(True)
plt.show()
def _position_and_velocity_TEME_km(self, jd):
"""Return the raw true equator mean equinox (TEME) vectors from SGP4.
Returns a tuple of NumPy arrays ``([x y z], [xdot ydot zdot])``
expressed in kilometers and kilometers per second.
"""
minutes_past_epoch = (jd.ut1 - self._sgp4_satellite.jdsatepoch) * 1440.
position, velocity = sgp4(self._sgp4_satellite, minutes_past_epoch)
return (array(position), array(velocity))
def extrapolateShort(self):
for numsat in range(0, len(self.catalog.line1) - 1):
# формирование массива данных рассчётов
line1 = self.catalog.line1[numsat]
line2 = self.catalog.line2[numsat]
sat1 = twoline2rv(line1, line2, wgs72)
line1 = self.catalog.line1[numsat + 1]
line2 = self.catalog.line2[numsat + 1]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (self.catalog.JD[numsat + 1] -
self.catalog.JD[numsat]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
self._sig.append(FullSigma(x1, x2))
return self._sig
def test_sgp4(client):
""" test the sgp4 device interface """
tsince = np.linspace(0, 100, client.n, dtype=np.float64)
sgp4.sgp4(tsince, client.whichconst_array, client.satrec_array)
array = []
for ts in tsince:
r, v = prop.sgp4(client.Satrec(), ts, wgs72)
array.append([r[0], r[1], r[2], v[0], v[1], v[2]])
expected = np.array(array)
assert np.allclose(expected, client.satrec_array[:, 94:])
def propogate_over_range(satellite, date, min_time, max_time):
# First we catch the previous satellite up to the midway point
for tsince in range(min_time, max_time):
# get current position and velocity in ECI
position_eci, velocity_eci = sgp4(satellite, tsince)
interval_date = increment_date_by_minutes(date, tsince)
time_string = TIME_TEMPLATE.format(interval_date)
x_csv_writer.writerow([time_string, position_eci[0], '0'])
y_csv_writer.writerow([time_string, position_eci[1], '0'])
z_csv_writer.writerow([time_string, position_eci[2], '0'])
def calcLong_R(catalog, number=0):
''' Возвращает массив полных ошибок "длинных интервалов"
'''
line1 = catalog.line1[number]
line2 = catalog.line2[number]
sat1 = twoline2rv(line1, line2, wgs72)
time = []
sig = []
for numsat in range(0, len(catalog.line1)):
line1 = catalog.line1[numsat]
line2 = catalog.line2[numsat]
sat2 = twoline2rv(line1, line2, wgs72)
dT = (catalog.JD[numsat] - catalog.JD[number]) * 24 * 60
x1, v1 = sgp4(sat1, dT)
x2, v2 = sgp4(sat2, 0)
time.append((catalog.JD[numsat] - catalog.JD[number]))
sig.append(fullSigma(x1, x2))
return sig, time
def _position_and_velocity_TEME_km(self, t):
"""Return the raw true equator mean equinox (TEME) vectors from SGP4.
Returns a tuple of NumPy arrays ``([x y z], [xdot ydot zdot])``
expressed in kilometers and kilometers per second. Note that we
assume the TLE epoch to be a UTC date, per AIAA 2006-6753.
"""
sat = self.model
minutes_past_epoch = (t._utc_float() - sat.jdsatepoch) * 1440.0
if getattr(minutes_past_epoch, 'shape', None):
position = []
velocity = []
error = []
for m in minutes_past_epoch:
p, v = sgp4(sat, m)
position.append(p)
velocity.append(v)
error.append(sat.error_message)
return array(position).T, array(velocity).T, error
else:
position, velocity = sgp4(sat, minutes_past_epoch)
return array(position), array(velocity), sat.error_message
def propogate_over_range(satellite, date, min_time, max_time):
# First we catch the previous satellite up to the midway point
for tsince in range(min_time, max_time):
# get current position and velocity in ECI
position_eci, velocity_eci = sgp4(satellite, tsince)
interval_date = increment_date_by_minutes(date, tsince)
time_string = TIME_TEMPLATE.format(interval_date)
# transform rectangular coordinates to spherical coordinates
position_sp = spherical(position_eci)
velocity_sp = spherical(velocity_eci)
phi_csv_writer.writerow([time_string, position_sp[0], '0'])
theta_csv_writer.writerow([time_string, position_sp[1], '0'])
def _position_and_velocity_TEME_km(self, t):
"""Return the raw true equator mean equinox (TEME) vectors from SGP4.
Returns a tuple of NumPy arrays ``([x y z], [xdot ydot zdot])``
expressed in kilometers and kilometers per second. Note that we
assume the TLE epoch to be a UTC date, per AIAA 2006-6753.
"""
sat = self._sgp4_satellite
epoch = sat.jdsatepoch
minutes_past_epoch = (t._utc_float() - epoch) * 1440.
if getattr(minutes_past_epoch, 'shape', None):
position = []
velocity = []
error = []
for m in minutes_past_epoch:
p, v = sgp4(sat, m)
position.append(p)
velocity.append(v)
error.append(sat.error_message)
return array(position).T, array(velocity).T, error
else:
position, velocity = sgp4(sat, minutes_past_epoch)
return array(position), array(velocity), sat.error_message
def envicosmos(tle1,tle2):
whichconst = 'wgs72'
#whichconst = wgs72
f1=open(tle1+'.tle')
f2=open(tle2+'.tle')
out1=open('envi.sal','w+')
out2=open('cosmos.sal','w+')
archivos=[f1,f2]
var=0
for tlefile in archivos:
var = var + 1
tlelines = iter(tlefile.readlines())
for line1 in tlelines:
if not line1.startswith('1'):
continue
line2 = next(tlelines)
satrec = twoline2rv(line1, line2, whichconst) # es un objeto de clase (satelite)
mu = satrec.whichconst.mu
epocatle=satrec.jdsatepoch
print 'epoca del tle [jd] = ', epocatle
jdini=jday(2008,1,9,18,0,0.0)
tini=(jdini-epocatle)*1440.0
print(tini)
tintervalo=np.arange(0,7200,1)
for t1 in tintervalo:
t=tini+t1/60.0
r, v = sgp4(satrec, t)
tjd=epocatle+t/1440.0 # dia juliano correspondiente al t en min.
"""Impresion de salida"""
year, mon, day, hr, minute, sec = invjday(tjd)
fecha = str(year)+'/'+str(mon)+'/'+str(day)+' '+str(hr)+':'+\
str(minute)+':'+str(sec)+' '+str(tjd)+' '+str(r[0])+' '+\
str(r[1])+' '+str(r[2])+' '+str(v[0])+' '+\
str(v[1])+' '+str(v[2])+'\n'
if var == 1:
out1.write(fecha)
else:
out2.write(fecha)
# year2,mon2,day2,hr2,minu2,sec2=invjday(2454475.29201)
# print year2,mon2,day2,hr2,minu2,sec2
"""
def test_sgp4_g(client):
""" test the sgp4 device propagation engine """
@cuda.jit('void(float64[:], float64[:, :], float64[:, :])')
def sample_function(tsince, which_const, satrec):
idx = cuda.grid(1)
stride = cuda.gridsize(1)
for i in range(idx, tsince.shape[0], stride):
sgp4.sgp4_g(tsince[i], which_const[i, :], satrec[i, :])
tsince = np.linspace(0, 100, client.n, dtype=np.float64)
sample_function(tsince, client.whichconst_array, client.satrec_array)
array = []
for ts in tsince:
r, v = prop.sgp4(client.Satrec(), ts, wgs72)
array.append([r[0], r[1], r[2], v[0], v[1], v[2]])
expected = np.array(array)
assert np.allclose(expected, client.satrec_array[:, 94:])
def trad(jd_array, fr_array):
from sgp4.earth_gravity import wgs72
from sgp4.io import twoline2rv
from sgp4.propagation import sgp4
sats = []
lines = iter(text.splitlines())
for name in lines:
line1 = next(lines)
line2 = next(lines)
sat = twoline2rv(line1, line2, wgs72)
sats.append(sat)
sats = sats[:20] # first 20 sats
print(len(sats), 'pure Python sats')
print(len(jd_array), 'and', len(fr_array), 'times')
zipped_times = list(zip(jd_array, fr_array))
for sat in sats:
for jd, fr in zipped_times:
t = (jd - sat.jdsatepoch + fr) * 1440.0
r, v = sgp4(sat, t)
# setup for reading TLE file all at once
tles = open(tlefile, 'r')
tlelines = tles.readlines()
nolines = len(tlelines)
tles.close()
satrec = []
# generate satrec, here one for all, but can also do one at a time (satrec1)
startline = linespertle - 2
for i in range(startline, nolines, linespertle):
# create satellite object
satrec1 = twoline2rv(tlelines[i], tlelines[i + 1], wgs84)
# append until all objects are read in
satrec.append(satrec1)
print(satrec)
# obtain position and velocity at reference epoch
minday = 1440.0 #minutes per day, input in minutes needed (see sgp4)
posvel = [sgp4(n, (jd_epoch - n.jdsatepoch) * minday)
for n in satrec] # state in km and km/s
nobj = len(posvel) # how many objects
r = [posvel[i][0] for i in range(nobj)] # position at epoch in km
v = [posvel[i][1] for i in range(nobj)] # velocity at epoch in km/s
print(r)
print(v)
# those are the position and velocity at the epoch you have defined, for multiple epochs you can make a vector or a for loop
# which then give you the full orbit
def sgp4(self, jd, fr):
tsince = (jd - self.jdsatepoch + fr) * minutes_per_day
r, v = sgp4(self, tsince)
return self.error, r, v
def propagate(self, year, month=1, day=1, hour=0, minute=0, second=0.0):
j = jday(year, month, day, hour, minute, second)
m = (j - self.jdsatepoch) * minutes_per_day
r, v = sgp4(self, m)
return r, v
(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)):
r = np.ndarray((len(a), j + 1, 3))
v = np.ndarray((len(a), j + 1, 3))
err = np.ndarray((len(a), j + 1), 'uint8')
jd = np.zeros((j + 1, ))
fr = np.ndarray((j + 1, ))
for i in range(j):
def invoke_satrec(self, satrec, tsince):
r, v = sgp4(satrec, tsince)
e = satrec.error
emsg = satrec.error_message
return e, emsg, r, v
def predict(self, satrec, startJTime, obsPos):
obsGeo={'x':obsPos['lon'],'y':obsPos['lat'],'z':obsPos['alt']}
obsEci={'x':0,'y':0,'z':0}
satGeo={'x':0,'y':0,'z':0}
satEci={'x':0,'y':0,'z':0}
bearingPrev = 0 #initialize bearing buffer
bearingDiffPrev = 100 #initialize bearing difference buffer
beginnerFlag = 2 #ignore the first 2 iterations for propagation init.
propCnt = 0 #initialize propagation count
error = 0 #error flag
iteLimit = iteLimitDef #propagation itemration limit
halfSwath = swath/2
startEpoch = startJTime
actualEpoch = startJTime
surfaceDistance = 0
bearing = 0
tspan = tspanDef
tspanBuff = 0
passedObsBuff = 0
visibleBuff = 0
passedObs = 0
visible = 0
#Start Propogation
bearingPrecision=0.0001
while (not(passedObs and visible and (math.fabs(bearingDiffPrev) < bearingPrecision))
and not error):
propCnt=propCnt+1
if propCnt > iteLimit-1:
if self.verbose:
print 'Exceed iteration limit.'
error=1
dtMinutes=(actualEpoch - satrec.jdsatepoch)*mpd
r,v=sgp4(satrec,dtMinutes)
satEci={'x':r[0],'y':r[1],'z':r[2]}
satVel={'x':v[0],'y':v[1],'z':v[2]}
epoch=actualEpoch
satGeo=self._eci2geo(satEci, actualEpoch)
obsEci=self._geo2eci(obsGeo, actualEpoch)
scn=self._getVec(obsEci,satEci) #scan direction vector from sat to obs
bearingRaw=self._getAng(scn,satVel)*rad2deg
bearing=bearingRaw
if satGeo['x'] > obsGeo['x']:
bearing=0-bearingRaw
bearingDiff=math.fabs(bearing)-90
#check if propogation had passed the observer
passedObs=0
if ((bearingDiff*bearingDiffPrev < 0) and not beginnerFlag):
passedObs=1
#decrease beginner flag count till zero
beginnerFlag=beginnerFlag-1
beginnerFlag=math.fabs(beginnerFlag*(beginnerFlag>0))
#update bearing buffers
bearingDiffPrev=bearingDiff
bearingPrev=bearing
#Spherical Earth big circle distance
if self.sphericalEarth:
ang=self._getAng(obsEci,satEci)
surfaceDistance=(ang*earthR)
try:
surfaceDistance_v=self.getDis(obsGeo,satGeo)
except:
surfaceDistance_v=0
else:
#Vincenty's Formulae
try:
surfaceDistance=self.getDis(obsGeo,satGeo)
except:
if self.verbose:
print 'Vincenty\'s formulae failed. Fall back to spherical Earth.'
ang=self._getAng(obsEci,satEci)
if self.verbose:
print 'Angle between coordinated: '+'%.3f'%ang
surfaceDistance=(ang*earthR)
visible=0
if (surfaceDistance < halfSwath):
visible=1
actualEpoch=actualEpoch+tspan/spd
if ((not passedObsBuff and passedObs) and (visibleBuff and not visible)):
visible=1
#update buffer
passedObsBuff = passedObs
visibleBuff = visible
if (passedObs and visible):
tspan=float(tspan)/(-20.)
dx=satEci['x']-obsEci['x']
dy=satEci['y']-obsEci['y']
dz=satEci['z']-obsEci['z']
slant=math.sqrt(dx*dx+dy*dy+dz*dz)
alpha=self._getAng(obsEci,satEci)
scanAngle=math.asin(earthR*math.sin(alpha)/slant)*rad2deg
#Correction will only be applied when spherical earth assumption is true.
if self.applyCorrection and self.sphericalEarth:
endTimeJulUtc=self._applyCorrection(actualEpoch,obsGeo['y'])
else:
endTimeJulUtc=actualEpoch
endTimeJulLoc=endTimeJulUtc+(self.timeZone)/24.
iniTimeJulLoc=startEpoch+(self.timeZone)/24.
# print 'do return'
return {'satLat':satGeo['y'],'satLon':satGeo['x'],'satAlt':satGeo['z'],
'obsLat':obsGeo['y'],'obsLon':obsGeo['x'],'obsAlt':obsGeo['z'],
'satVelX':satVel['x'],'satVelY':satVel['y'],'satVelZ':satVel['z'],
'satEciX':satEci['x'],'satEciY':satEci['y'],'satEciZ':satEci['z'],
'obsEciX':obsEci['x'],'obsEciY':obsEci['y'],'obsEciZ':obsEci['z'],
'scanAngle':scanAngle,
'distance':surfaceDistance,
'bearing':bearing,
'timeEndUTC':endTimeJulUtc, 'timeIniUTC':startEpoch,
'timeEndLOC':endTimeJulLoc, 'timeIniLOC':iniTimeJulLoc,
'timeZone':timeZone,
'propCnt':propCnt, 'timeSpan':tspan,
'error':error}
def run_legacy_sgp4(satrec, tsince):
r, v = sgp4(satrec, tsince)
return (satrec.error, satrec.error_message), r, v
def sgp4(self, jd, fr):
tsince = ((jd - self.jdsatepoch) * minutes_per_day +
(fr - self.jdsatepochF) * minutes_per_day)
r, v = sgp4(self, tsince)
return self.error, r, v
def sgp4_tsince(self, tsince):
r, v = sgp4(self, tsince)
return self.error, r, v