Global Positioning System

With the initiation of the navigation accuracy prediction algorithm used to estimate the amount of GPS solution (location and time) error for military receivers, the capability to accurately predict solution errors due to the major GPS error sources is growing. Although some sources of error within the GPS solution have been previously analyzed, modeled, and or accounted for within various modeling efforts, a formal evaluation of the seven major error sources that distort GPS activity has not been officially conducted up until this point. This research offers a logical assessment of alt the major GPS error sources and their definitive impact on the end user. This research describes the major error sources in the GPS solution, which includes error sources from the spacecraft, propagation of the signal through space, and receiver errors for a representative family of military receivers. Once we define these error sources, we prioritize these sources with respect to benefit-to-cost ratios. We base the benefit-to-cost ratio on an error's accountability to the modeling effort required.