Remote sensing of water salinity at decameter wavelengths

The possibility of remote sensing of surface water salinity in the decametric wave range is studied. The theoretical consideration of sensitivities to salinity variations proves the decametric range to be best for measuring small water salinities [0.3-5 parts per thousand ( ⁰/₀₀) at 30 MHz]. The conclusion is confirmed by 30 MHz radar experiments, which show a good agreement with the in situ data in the range 0.3-30 ⁰/₀₀. Radar contrasts of about 0.35 db and 1.6 db are observed when salinity changes from 0.3 ⁰/₀₀ to 1.2 ⁰/₀₀ and to 30 ⁰/₀₀, correspondingly