docs: def ComputeLightTravelTime(Det1Pos, Det2Pos):
      """ ComputeLightTravelTime - function to compute light travel time between
  	two GW detectors at positions Det1Pos and Det2Pos.
  
  	Det1Pos - (3,) array. Position vector of detector 1.
  	Det2Pos - (3,) array. Position vector of detector 2.
  
  	Returns travelTime - Light travel time between two GW detectors at
  			     positions Det1Pos and Det2Pos [s].
  
          Sarah Gossan 2012. Adapted from TimeDelay.c, written by Jolien
  	Creighton, David Chin, Steven Fairhurst, Kipp Cannon, Alexander Dietz, 
  	Drew Keppel 2007."""
  
      # Get relative position vector
      Det21Pos = Det2Pos - Det1Pos
    
      # Dot difference vector into itself to get magnitude of detector separation
      dist = np.sqrt(np.dot(Det21Pos,Det21Pos))
  
      # Normalise with speed of light
      travelTime = dist/c
  
      return travelTime