In this paper the objective of the ATS-F/NIMBUS-E Tracking Experiment, the first of such kind, is presented. Specifically, this experiment has a two-fold purpose: First, to gain experience in the practical use of satellite-to-satellite range and range rate data for very accurate orbit determination (this was its original intent); and second, to evaluate the real usefulness of such a technique for geodetic studies despite the fact that the 1000 km NIMBUS orbit is not ideally suited for such a purpose.The accuracies of the tracking systems of the satellite-to-satellite and satellite-to-ground link (ATS-F to the Rosman, N.C. ground station) will be ~ 0.035 cm/s in range rate and ~ 1 m in range – utilizing a 10 s integration time. With these values one obtains, based upon performed error analyses, orbit height errors in the order of 0.1 to 0.3 m for the near earth orbiting NIMBUS spacecraft. This experiment will therefore hopefully prove to be a significant first step for future Earth applications spacecraft carrying altimeters systems for measuring ocean height variations.In addition, laser corner reflectors placed on board the ATS-F will make a total independent position determination of this spacecraft to approximately 15 m to 30 m possible, assuming that the location errors of four laser tracking stations used to determine the orbit are about 3 m or 5 m in each component respectively, with laser ranging system noise errors of 1.2 m and bias errors of 0.15 m. A small position error of the ATS-F, the ‘orbiting tracking station’ is essential in order to make full usage of the small satellite-to-satellite tracking errors mentioned.For purpose of geodetic studies, one of the final goals, range rate variations of 0.1 cm/s or less corresponding to surface gravity anomaly of 20 mgal or less (over a half-width of 100 km on the Earth surface), will have to be measured during a time interval of approximately, say, 30–60 s. These values are within the range of the planned tracking systems accuracies for ATS-F and NIMBUS-E.
Assessment of Influence of Sample Averaging on Accuracy of Point Coordinates Measurement Performed Using Laser Tracking Systems
