A new hydrostatic mapping function for tropospheric delay estimation

A new hydrostatic mapping function is proposed by modifying the analytical solution of the Chapman grazing incident (Chi) function. Applicability of this mapping function is evaluated over the Indian region by comparing it with the true value of mapping function estimated through ray-tracing the refractivity profile of neutral atmosphere as well as by comparing it with the Niell and Global Mapping Functions. This comparison shows that the new mapping function, agrees very well with the ray-traces values and it is in par with if not better than the other global mapping functions for very high zenith angles up to ∼88°.