Precise orbits for ground-based GPS meteorology: processing strategy and quality assessment of the orbits determined at geodetic observatory Pecny

The GPS meteorology has been the driving force behind the near real-time (NRT) GPS analyses during the past few years. High availability of precise near real-time GPS orbits is essential for obtaining reliable solutions in almost all applications. This is especially true when estimating the troposphere parameters. Besides the demand on high accuracy, the orbit products should stand out for their stability in production as well as for their completeness in set of satellites. The most likely candidates for the applicable orbits are products of the International GPS Service (IGS). We will outline, at first, the results of our monitoring activity of the IGS ultra-rapid orbits provided beside their routine usage in Geodetic Observatory Pecny (GOP). Thereafter, we will explain our procedure for NRT orbit determination using an efficient technique of combining short orbit arcs into the final orbits over 2-3 days. Our official orbit results, as well as testing variants of the combination, were evaluated using the IGS final and ultra-rapid orbit products. Finally, we will demonstrate the direct application of our orbits in the NRT GPS analyses for sensing the regional and global troposphere.