Amplitude Distribution of Low Grazing Angle G-band Littoral Sea Clutter

G-band radar sensing of the marine environment is of interest for maritime autonomy, however at present, no phenomenological data of low grazing angle sea clutter at this frequency is available in the literature. Future sensor design is contingent on the modeling of empirical data, with polarization expected to be a key parameter. This paper presents the results of an analysis of data of radar returns from the water’s surface gathered in 2022 at Coniston Water, UK. The difference in amplitude distribution and normalized radar cross section (NRCS) between HH (horizontal-horizontal) and VV (vertical-vertical) polarization is shown for two $0.5^{\mathrm{o}}$ wide grazing angle swaths centered at $2^{\mathrm{o}}$ and $4^{\mathrm{o}}$. HH is seen to produce longer-tailed distributions than VV for both swaths, with a mean NRCS for thresholded data (i.e. for wave signal peaks) of −33.3dB (HH) and −35.2dB (VV) for the swath centered at $2^{\mathrm{o}}$, and −38.6dB (HH) and −41.6dB (VV) for the swath centered at $4^{\mathrm{o}}$.