Simultaneous characterization of propagation within the marine boundary layer at X-, Ka- and W-band

The performance of radar sensors operating within the marine boundary layer is severely influenced by the actual atmospheric conditions, the sea surface and the geometry between radar and reflection point. Propagation models are in existence, which cope with the varying environment and allow a performance prediction for sensors in different radar bands. To assess the propagation within different layers simultaneously at X-, Ka- and W-band an experiment was performed using the experimental three frequency radar MEMPHIS operating against point targets at different heights above sea, carried on a naval vessel, which moved on outbound and inbound courses to ranges well beyond horizon. In-situ measurements included recordings of atmospheric properties and sea surface parameters. Based upon the environmental measurements, refractivity profiles were calculated. With the help of the vertical refractivity gradient and the air sea temperature difference, conditions for the radar propagation were determined.The experimental results were used to validate respective simulations with the parabolic equation model TERPEM. In conclusion, the experimental results and calculations underline the importance of the environmental characterization of the marine boundary layer with high temporal and spatial resolution.This paper describes the experimental approach and gives representative results for measurement and simulation