@spiceErrorCheck<EOL>def ltime(etobs, obs, direct, targ):
etobs = ctypes.c_double(etobs)<EOL>obs = ctypes.c_int(obs)<EOL>direct = stypes.stringToCharP(direct)<EOL>targ = ctypes.c_int(targ)<EOL>ettarg = ctypes.c_double()<EOL>elapsd = ctypes.c_double()<EOL>libspice.ltime_c(etobs, obs, direct, targ, ctypes.byref(ettarg),<EOL>ctypes.byref(elapsd))<EOL>return ettarg.value, elapsd.value<EOL>
This routine computes the transmit (or receive) time
of a signal at a specified target, given the receive
(or transmit) time at a specified observer. The elapsed
time between transmit and receive is also returned.

http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/ltime_c.html

:param etobs: Epoch of a signal at some observer
:type etobs: float
:param obs: NAIF ID of some observer
:type obs: int
:param direct: Direction the signal travels ( "->" or "<-" )
:type direct: str
:param targ: NAIF ID of the target object
:type targ: int
:return: epoch and time
:rtype: tuple