Over the Horizon Skywave HF Radar Object Altitude Estimation

The ability to perform persistent, wide-area surveillance of the air and sea approaches to the U.S. mainland has been and remains a primary mission requirement for both the North American Aerospace Defense Command (NORAD) and the United States Northern Command (USNORTHCOM).  In addition to major contributions to illegal drug interdiction, in light of an emerging threat posed by terrorist use of UAVs, this ability also supports Department of Homeland Security missions. However, current OTH radars are deficient in that they cannot provide object altitude information.  Therefore, they are unable to provide the accurate track information needed to discriminate surface and low-flying aerial targets or to effectively hand tracks off to other assets for interception.  This deficiency arises from the dispersive nature of the ionosphere itself the location of the reflection point varies with time.  TSC proposes an innovative track filter technique to dynamically estimate and correct for the Total Electron Count (TEC) experienced by the signal.  This correction will allow the application of target height finding techniques that TSC had developed for other applications. BENEFIT: Effective application of target height finding techniques to OTH radar will allow these valuable, wide-area surveillance assets to:  1) effectively distinguish air and surface traffic, 2) effectively hand-off target tracks to other sensors, and 3) have their outputs more easily integrated into the C2 enterprise.