Environmental characterization of the marine boundary layer for electromagnetic wave propagation

摘要

Radar and infrared propagation drastically depend on the meteorological and oceanographic conditions. Concerning a joint sea trial of German research institutes at the Baltic Sea 2001, FWG was responsible for the environmental characterization of the marine boundary layer. In-situ measurements included recordings of atmospheric properties and sea surface parameters. They were studied by two multi-sensor buoys, on board a vessel and with radiosondes. Pressure, air temperature and humidity were measured from the sea surface to 1 km altitude. The free drifting buoys which have been constructed at FWG offer the opportunity to gain unperturbed, time resolved information about environmental parameters up to 5 m above sea level. Based on the in-situ measurements refractivity profiles can be calculated. With the help of the vertical refractivity gradient and the air sea temperature difference, conditions for radar and infrared propagation are determined. Further experimental results include wind speed and direction, wave height, rain rate and other important parameters. Taking advantage of the parabolic equation model radar propagation is calculated numerically. 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.