Synchromesh, a practical enhancement to GPS service

It is pointed out that the accuracy of Global Positioning System (GPS) navigation depends upon each satellite's having a good representation of both satellite constellation time and present position. Prediction 'fits' are to be derived on the ground and transmitted (uploaded) to the constellation on a regular basis, providing each satellite with the best current estimate of time and position. By the use of the Synchromesh concept, the required frequency of satellite uploads can be greatly reduced, while still maintaining specification GPS accuracy. According to the Synchromesh approach of time correction, each satellite determines the relationship of its own clock to those of the satellites in the constellation which are visible at that measurement time, and adjusts its clock toward the bet fit.