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

Abstract

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

Joint French-German radar measurements for the determination of the refractive index in the maritime boundary layer

“…The MEMPHIS radar system [7] employs three front-ends at 9.6 GHz, 35 GHz and at 94 GHz, which can be operated simultaneously. The 35-GHz subsystems is fully polarimetric, while the 10 GHz and 94 GHz front ends allow only the assessment of co-and cross polarization.…”

“…The knowledge of the refractive index is a critical problem for maritime radar applications in order to feed the wave propagation model. During the measurement campaigns VAMPIRA [2], [3], abnormal propagation events have been occurred in form of evaporated ducts. Clutter and propagation factor measurements have been carried out for all events.…”

Millimeter wave propagation above the sea surface during the Squirrel campaign

“…The ability to reliably detect and classify targets under all oceanographic and atmospheric conditions is still not fully developed and thus further research together with experiments towards a better understanding is still necessary. In this contribution we focus on a related measurement campaign which was performed in September 2011 in order to acquire more data and to gain confidence in the models used to model the propagation conditions [1,3].…”

Observations of anomalous propagation over waters near Sweden

“…A number of measurement campaigns have also been conducted in the Baltic sea, mainly focused on studying evaporation ducts. During these campaigns a combination of in situ measurements, radiosondes, and microwave measurements were performed and reported (see, e.g., Scholz and Förster, 2003;Förster et al, 2004;Essen et al, 2004;Förster and Riechen, 2006;Essen et al, 2012;Danklmayer et al, 2013Danklmayer et al, , 2015Danklmayer et al, , 2016a.…”