Evaluation of three antenna pattern measurements for a 25 MHz seasonde

The need for reliable surface current measurements from the SeaSonde high-frequency radar network is essential for Coast Guard search and rescue missions, oil spill mapping, and algal bloom tracking. To ensure the advancement of accurate surface current maps, antenna calibrations need to be performed to correct for bearing errors at the radial level. Due to environmental interference, three different antenna pattern measurements were performed at a 25 MHz radar site located in Staten Island, NY (SILD). Spectra taken over a three-day period starting from Oct. 15, 2014 were reprocessed using the different pattern methods and analyzed with the ideal radial measurements from the same time period at three separate bearing locations 9 km offshore in the New York Harbor.