GNSS tomography, from epoch local solution to country-wide near real time system

GNSS meteorology is the remote sensing of the atmosphere (particularly troposphere) using Global Navigation Satellite Systems (GNSS) to derive information about its state. Over past five years the studies on GNSS tomography were performed in the Wroclaw University of Environmental and Life Sciences on the GNSS tomography. The results for epoch wise researches, allows to develop stable tomography numerical model (its optimal size and shape), assess errors, define special constraints, include in the model results of the analysis of the air flow. This paper presents the issues of the Near Real Time (NRT) tomographic model construction, the building of the required IT infrastructure, developing algorithms for effective numerical processing, requirements for NRT products, means of integration with other measurement techniques, comparison with weather prediction models.