A Robust Solution to High-Accuracy Geolocation: Quadruple Integration of GPS, IMU, Pseudolite, and Terrestrial Laser Scanning

Reliable and accurate geolocation is essential for airborne and land-based remote sensing applications. The detection, discrimination, and remediation of unexploded ordnance (UXO) and other munitions and explosives of concern (MEC) using the currently available detection and geolocation technologies often yield unsatisfactory results, failing to detect all MEC present at a site or to discriminate between MEC and nonhazardous items. Thus, the goal of this paper is to design and demonstrate a high-accuracy geolocation methodology that will address centimeter-level relative accuracy requirements of a man-portable electromagnetic (EM) sensor system in open and impeded environments. The proposed system design is based on the tight quadruple integration of the Global Positioning System (GPS), the inertial measurement unit (IMU) system, the terrestrial radio-frequency (RF) system pseudolite (PL), and terrestrial laser scanning (TLS) to support high-accuracy geolocation for a noncontact EM mapping system in GPS-challenged environments. The key novel component of the proposed multisensor system is the integration of TLS that can provide centimeter-level positioning accuracy in a local frame and thus enables a GPS/IMU/PL-based navigation system to achieve both high absolute and relative positioning accuracy in GPS-impeded environments. This paper presents the concept design of the quadruple integration system, the algorithmic approach to data integration with a special emphasis on TLS integration with GPS/IMU/PL, and the performance assessment based on real data, where centimeter-level relative geolocation accuracy is demonstrated during the GPS signal blockage.