The Attenuation Rate in Fresh Water at VHF Frequencies

The attenuation rate of the electromagnetic energy in samples of fresh water has been measured at frequencies between 33 and 363 MHz. The technique employed the HP 8410A network analyzer and a broad-band transmission resonance cavity and provided reliable results which agree well with theory. The results suggest that it should be possible to develop a VHF radar system capable of sensing the depth of shallow fresh water for remote sensing applications.