<h2>AAS 95-385</h2><h2>Stochastic Clock Model for Definitive Sequential Orbit Determination</h2><h4>J. R. Wright and W. A. Chuba, Applied Technology Associates, Inc., Exton, PA</h4><h2> Abstract </h2>The performance of definitive sequential orbit determination algorithms which use one-way range or Doppler measurements depends on the clocks used to produce the measurements.  Given an Allan variance diagram for a particular clock, our problem is to derive, build, and validate an associated stochastic clock model for use in definitive sequential orbit determination.  Realistic simulations enable validation of a stochastic clock model, and evaluation of associated orbit accuracy performance.  Realistic simulation of random clock performance uses a Weiner-Levy sequence (random walk functional), its differences (white noise), and its sums (double integral white noise).  The calculation of appropriate clock covariance functions for clock phase and fractional frequency follows easily for use in definitive sequential orbit determination.<br><br>