A First-Order,Worldwide,Ionospheric,Time-Delay Algorithm.

摘要

A first-order model algorithm designed to reduce ionospheric time-delay errors by approximately 50% rms on a world-wide basis for single frequency users of the Global Positioning Systen/NAVSTAR is described. The algorithm was designed for greatest accuracy during times of day when ionospheric time-delay errors are expected to be largest. The algorithm is available in several options from one which requires only a monthly mean solar-flux value to one which requires 9 daily or monthly update coefficients. Several approximations also are made in the geometry calculations to further reduce operational user computer storage and running time requirements. (Author)