End to end simulation for Normalized Differential Spectral Attenuation (NDSA) measurements between two LEO satellites: :Performance analysis in the Ku/K bands

The NDSA method is a novel differential measurement way for estimating the total content of water vapor (IWV, Integrated Water Vapor) along a tropospheric propagation path between two Low Earth Orbit (LEO) satellites. NDSA is based on the simultaneous measurement of the total attenuation at two relatively close frequencies in the Ku/K bands, and on the estimate of a "spectral sensitivity parameter" that can be directly converted into IWV. NDSA is potentially able to emphasize the water vapor contribution, to cancel out all spectrally flat unwanted contributions and to limit the impairments due to tropospheric scintillation. In this paper we focus on the measurement accuracy of the spectral sensitivity parameter. Specifically, we examine such accuracy at three different frequencies and for two models of atmospheric structure.