LatLonAlt to ECEF

LLA2ECEF.py

# WGS84 ellipsoid constants
WGS84_A = 6378137 # radius
WGS84_E = 8.1819190842622e-2  # eccentricity

def LLA2ECEF(lat, lon, alt):
    """
    Converts latitude (deg), longitude (deg) and altitude (m) to ECEF frame
    https://en.wikipedia.org/wiki/Geographic_coordinate_conversion#From_geodetic_to_ECEF_coordinates
    
    Returns:
    X, Y, Z in meters
    """
    clat = np.cos(np.deg2rad(lat))
    slat = np.sin(np.deg2rad(lat))
    clon = np.cos(np.deg2rad(lon))
    slon = np.sin(np.deg2rad(lon))

    N = WGS84_A / np.sqrt(1.0 - (WGS84_E**2) * (slat**2))

    X = (N + alt) * clat * clon
    Y = (N + alt) * clat * slon
    Z = (N * (1.0 - WGS84_E * WGS84_E) + alt) * slat
    
    return X, Y, Z