Application of the Hill-Clohessy-Wiltshire equation in GNSS orbit prediction

We present an initial state correction algorithm for GNSS orbit prediction that uses the solution of the Hill-Clohessy-Wiltshire equation to build the Jacobian matrix. This algorithm improves the accuracy of GNSS orbit prediction through adding one or more observations. In the tests of 14 days orbit prediction, by adding one broadcast ephemeris as an observation collected before the initial BE with a long enough interval, we get orbit-only User Range Error within 70 meters, and orbit errors in the radial direction is less than 15 meters. In tangential direction, the error is within 400 meters.