NASA Ocean Color

ocssw V2022
 def orb2lla(orb):
     # Compute geodetic longitude, latitude and altitude 
     # from Cartesian orbit vector in ECR coordinates
     # Uses geodetic approximation from Patt and Gregg, IJRS, 1993.
     # input: orb: position vector[0,1,2]
     # reference: orb2lla.pro by Fred Patt
     # ported to Python by Liang Hong, 2/13/2020
     
     import numpy as np
     
     RE = 6378.137           # Earth equatorial radius (km)
     REM = 6371.0            # Earth mean radius (km)
     F = 1.0/298.257       # Earth flattening factor
     OMF2 = (1.0-F)**2
         
     # Compute longitude
     lon = np.rad2deg(np.arctan2(orb[:,1],orb[:,0]))
     
     # Compute geodetic latitude 
     rad = np.sqrt(np.square(orb[:,0])+np.square(orb[:,1])+np.square(orb[:,2]))
     omf2p = (OMF2*REM + rad - REM)/rad
     pxy = np.square(orb[:,0])+np.square(orb[:,1])
     temp = np.sqrt(np.square(orb[:,2]) + omf2p*omf2p*pxy)
     lat = np.rad2deg(np.arcsin(np.array(orb[:,2])/temp))
  
     # Compute altitude
     clatg = np.cos(np.arctan(OMF2*np.tan(np.deg2rad(lat))))
     rl = RE*(1.0-F)/np.sqrt(1.0-(2.0-F)*F*np.square(clatg))
     alt = rad - rl
     
     return lon,lat,alt
  
  
orb2lla.orb2lla
def orb2lla(orb)
Definition: orb2lla.py:1