Enhancements of River Water Level Monitoring Method Using COSMO-SkyMed SAR Images

The problem of not having persistent river levels monitoring via satellite remote sensing is of considerable importance because the lack of this capability could affect the safety of inhabited areas near rivers. It has been shown that synthetic aperture radar (SAR) interferometry is a valid tool to measure the water surface of the river. Unfortunately, rivers can swell dynamically in less time than between two observations with the same geometric SAR parameters. Therefore, interferometric time series could not be used for effective emergency prevention and continuous monitoring because of geometric constraints. In this article, we propose an improvement of previous research by considering arbitrary geometric SAR acquisitions. The proposed method allows us to increase the possibility of image acquisition in order to drastically reduce the revisit time with respect to an interferometric acquisition strategy. Experimental results are consistent with the water level measurements from the in situ stations. Finally, the proposed procedure can potentially use data from any satellite system positioned in any orbit, not only sun-synchronous, in order to reduce time for more continuous monitoring of river levels.