The SATCROSS Measurement Campaign Applica on of the NDSA technique to a Ground-to-Ground Radio Link

The measure of water vapor (WV) in the lower troposphere is a critical issue, which still leaves important margins for improvements of observational data quality, as necessary for instance to enhance the forecast performance of Numerical Weather Prediction systems.A novel technique developed in recent theoretical ESA studies, called NDSA (Normalized Differential Spectral Attenuation), is based on the measure of differential attenuation of two continuous tones transmitted at 18.8 and 19.2 GHz on a line of sight radio link.These studies proved the good capabilities of the technique in the estimation of the integrated water vapor (IWV), thus fostering further research efforts, including those aimed at developing and testing a demonstrator capable to acquire the first NDSA measurements. We recently designed and implemented a first demonstrator of such technique operating in a ground-to-ground link configuration. The first prototype was upgraded with the realization of an improved transmitter and receiver units to ensure more accurate measurements of IWV. We will report and discuss the results of this activity and the results of a new measurements campaign conducted with the last prototype.The poster presentation will also describe the activities envisaged in the near and mid-term for further advancement of the instrument prototype, such as, in particular, a ground-to-air measurement configuration. The aim of this is a feasibility study for the realization of a system based on the NDSA technique that satisfies the basic requirements laying the foundations for the ultimate ambition of a NDSA space mission deployment.