static double computeDesiredEllipsoidMagnitude(final PlanetModel planetModel,final double z){
  return 1.0 / Math.sqrt((1.0 - z * z) * planetModel.inverseAbSquared + z * z * planetModel.inverseCSquared);
}

static double computeDesiredEllipsoidMagnitude ( final PlanetModel planetModel , final double z ) { return 1.0 / Math . sqrt ( ( 1.0 - z * z ) * planetModel . inverseAbSquared + z * z * planetModel . inverseCSquared ) ; }
compute the desired magnitude of a unit vector projected to a given planet model . the unit vector is specified only by a z value .
