|CODAR Patent Pending “Coastal HF Radar System for
In April 2016 CODAR Ocean Sensors, ltd. submitted Application No. 15/140,325 with the U.S. Patent & Trademark
Office and also filed officially for patents in Germany, China, Japan, and U.K.
CODAR’s invention describes the series of steps unique to HF radars that are needed to maximize the robustness and
utility of candidate warning messages sent to tsunami warning centers. The first steps in this are filtering, to remove false
alarms based on correlation with other information. The second involve QA (quality assurance), namely attaching a flag to
potential detections with a confidence level.
This invention describes how the q-factor spikes -- denoting a possible approaching tsunami --
are related to other information that may be used to filter and QA them to reduce false
alarms. For example, applications are available online that give the location of any subsea
earthquake worldwide; from this, a time window will be set up at the site, within which a
tsunami would be expected. Correlations with detection spikes from adjacent coastal sites
(e.g., within 50 km) will be used as a filter and QA flag. Finally, real-time correlation with
background currents (e.g., from storms) and external noise/ interference will guide credibility
determination for a potential alert spike candidate. This is a dynamic process, with alert
credibility changing as background seen by the radar varies with time.