Radio refractivity observations over the oceans using airborne microwave refractometer in tropics

Abstract

The coastal waters of Indian sub -continent do not have reliable measurements of fine structure of radio refractivity especially in near real-time basis needed to mitigate the effects of anomalous propagation for the defence communications as well as for antisubmarine warfare. This programme was designed to document the radio refractive layer structure and variations of the marine layer in tropical waters of India. The paper describes the above observations taken using the airborne microwave refractometer developed by the author at National Physical Laboratory, New Delhi. Typical observations taken (for the first time in India) under normal and anomalous propagation conditions are presented and the results are compared with the special shipborne observations made under MONEX operation over the coastal waters of India.