def m_dFdT(v_pos_dL_b, v_dL_cap_i, v_v_sat_i, q, t, dL):
qi = qnv.quatInv(q)
v_pos_dL_i = qnv.quatRotate(q, v_pos_dL_b)
height = np.linalg.norm(v_pos_dL_i) - R
height = height / 1e3
v_pos_dL_e = fs.ecif2ecef(v_pos_dL_i, t)
lat, lon = fs.latlon(v_pos_dL_e.reshape((3, )))
B = runigrf12(day, 0, 1, height, lat, lon)
v_B_n = np.vstack((B[0], B[1], B[2]))
v_B_n = v_B_n * 1e-9 #convert from nT to T
v_B_e = fs.ned2ecef(v_B_n.reshape((3, )), lat, lon)
v_dL_cap_e = fs.ecif2ecef(v_dL_cap_i, t)
v_v_sat_e = fs.ecif2ecef(v_v_sat_i, t)
e = qnv.dot1(qnv.cross1(v_v_sat_e, v_B_e), v_dL_cap_e)
i = e / mu_r
v_dF_e = dL * i * qnv.cross1(v_dL_cap_e, v_B_e)
v_dF_i = fs.ecef2ecif(v_dF_e, t)
v_dF_b = qnv.quatRotate(qi, v_dF_i)
v_dL_cap_b = v_L_b / np.linalg.norm(v_L_b)
v_dT_b = qnv.cross1(v_dL_cap_b, v_dF_b)
return v_dF_i, dL * v_dT_b
def test_independnt_of_radius(self, radius):
x1 = np.array([1., 2., -3.])
self.assertAlmostEqual(fr.latlon(radius * x1)[0], fr.latlon(x1)[0])
self.assertAlmostEqual(fr.latlon(radius * x1)[1], fr.latlon(x1)[1])
def test_z_symmetry_lat(self, value):
#self.assertEqual(2,2)
x1 = np.array([sin(value), cos(value), 13.])
self.assertAlmostEqual(
fr.latlon(x1)[0],
fr.latlon(np.array([1., 0., 13.]))[0])
def test_cases_file(self, value):
given, expected = np.asarray(
value[0]), value[1] #asarray to convert list to array
result = fr.latlon(given)
self.assertTrue(np.allclose([result[0], result[1]], expected))
self.assertEqual(type(result), tuple)
This code generates csv file for latitude, longitude, altitude (LLA) corresponding to time data.
ECI frame position is provided from sgp_output.csv
Time: (since epoch) in seconds
latitude: -90 to 90 degrees
longitude: -180 to 180 degrees (-180 excluded)
altitude: in meters
'''
m_sgp_output_i = np.genfromtxt('sgp_output.csv', delimiter=",")
N = m_sgp_output_i.shape[0]
m_sgp_ecef = np.zeros([N,4])
m_LLA = np.zeros([N,4])
for k in range(0,N):
if math.fmod(k,N/100) == 0:
print (int(100.*k/N))
v_i = m_sgp_output_i[k,1:4] #iniertial frame position
time = m_sgp_output_i[k,0] #time in sec
#get position in ecef
v_ecef = fs.ecif2ecef(v_i,time)
#get latitude and longitude and altitude
v_latlon = fs.latlon(v_ecef.copy())
alt = np.linalg.norm(v_i.copy()) - R_EARTH #in meters
m_sgp_ecef[k,0] = time
m_LLA[k,0] = time
m_sgp_ecef[k,1:4] = v_ecef
m_LLA[k,1:4] = np.append(v_latlon,alt)
np.savetxt('LLA.csv',m_LLA, delimiter=",")
print("LLA done")