Nonhydrostatics UNBab mapping function simplification for tropospheric delay

Abstract

Many operations are needed to calculate mapping function models due to the continued fractions character. For nonhydrostatics UNBab mapping function there are seven mathematical operations to calculate the mapping function value. This mapping function is chosen to be simplified due to its ability to calculate mapping function value down to 2 degree of elevation angle. To simplify the model, regression method is used in order to get the similar result. The computation time for the simplified model is reduced 3.9 times faster than the original model. The number of model operations of the simplified model is reduced 71.4 percent from the original model. So, the simplified mapping function model can be used to replace the original model. The sum of errors calculation can show that the deviation of the simplified model from the original models is not significant.