Integrated Radar/Optical/Inertial System for Precise Localization under Dense Foliage

To enable precise positioning capabilities in dense forestry areas, QuNav proposes to develop the technological approach of Positioning with Optical/Inertial Navigation and a Tree-map Enabled by Radar (POINTER). POINTER implements global and local aiding of inertial navigation system (INS) using features extracted from images of electro-optical (EO) sensors (ladar and video camera). Global aiding (i) extracts tree trunks from EO imagery data; (ii) matches them to a geo-referenced map; and, applies matched trunk features to mitigate the INS position drift. Local aiding operates without a priori map information. Position and attitude increments that are computed from a sequence of ladar and video images are utilized for the INS drift mitigation. One key benefit of combining global and local aiding components is the ability of POINTER to operate with sparse maps since local aiding can be applied between absolute position updates.POINTER can be optionally augmented with deeply integrated GPS/INS navigation (DIGINAV). DIGINAV employs long coherent integration to recover extremely weak GPS signals (30 to 40 dB below open-sky conditions). DIGINAV will not necessarily support a continuous position solution under dense canopy. Yet, fragmented satellite measurements can be still recovered thus providing additional updates to the overall sensor-fusion mechanization.