Measured data to verify the detectability for a small target on the sea-surface

Data using X-band radar and small Styrofoam sphere target were mesured. The measurement system transmitted a linear frequency modulation waveform that had initial carrier frequency 9.35 GHz, stepped carrier frequency interval 0.2 MHz, solid state power amplifier (SSPA) power 50 W, bandwidth 5 MHz, polarization of HH, pulse-repetition interval 0.4 ms, pulse-processing interval 16 ms, scan-repetition interval 0.75 s, and scan-processing interval 15 s. To obtain the measurements from the small Styrofoam sphere target in a sea environment, we conducted an experiment on the east shore of Yeongdeok-gun, Gyeongsangbuk-do, South Korea (lat: 34° 24' N, long: 129° 26' E) in two cases: (1) STSS with radius 0.4 m (i.e., RCS = −9 dBsm) at sea state 3 ~ 4 with wave height 1.2 to 2.2 m and wind velocity 6.3 to 13.5 m/s. the STSS had a velocity 0 m/s and was ~ 440 m away from the X-band radar at fixed azimuth direction and grazing angle 3°, so we obtained complex raw data, which were matched-filtered using replicas with different carrier frequencies at each scan.