HF Radar Calibration with Automatic Identification System Ships of Opportunity

Over 300 HF RADARs worldwide are producing ocean surface data that is used in oil spill response, search & rescue, vessel traffic management, and research. In the U.S. there are 100+ systems supplying real-time data to the Coast Guard, NOAA IOOS, OR&R and other operational groups. To provide the highest quality data to stakeholders, systems should be calibrated by measuring the receive antenna pattern. For the typical HF radar, this measurement is currently made with a portable transponder on a boat 1-2 km away. This method, while robust, is costly and limited by sea conditions. We demonstrated in Phase I that by associating AIS vessel identifications, which provide ship positions, with vessel radar echoes in HF radar data it is possible to reproduce the antenna pattern. The objective of Phase II research is to implement the method operationally. The prototype will consist of software to acquire AIS ship data and combine it with HF radar cross-spectra to produce antenna pattern measurements and their statistics. To accomplish this objective we will answer the remaining research questions from Phase I, expand the method to other operational HF radar bands (5, 25 and 42 MHz), and develop quantitative data quality metrics.