Direct Sensor Orientation in Airborne and Land-based Mapping Applications

The work described in this report is a summary of research and development in the area of GPS/INS (Global Positioning System/Inertial Navigation System) integration for direct georeferencing of imaging sensors to support precision airborne and land-based mapping. The research was conducted at the Ohio State University Center for Mapping and the Department of Civil and Environmental Engineering and Geodetic Science (CEEGS).The work presented here was supported by the National Aeronautics and Space Administration (NASA) grant, OSU # 733223, the Ohio Department of Transportation (ODOT) grant, OSU # 733488, and the Federal Department of Transportation (FDOT) grant, OSU # 739152.Since the early 1990s, the concept of Mobile Mapping Systems (MMS) has evolved from rather simple land-based systems to more sophisticated, real-time multi-tasking and multi-sensor systems, operational in land and airborne environments. Mobile Mapping technology has made a remarkable progress, notably expanding its use in remote sensing, and surveying and mapping markets. New systems are being developed and built for specialized applications, in support of land-based and airborne imaging sensors, aimed at automatic data acquisition for GIS databases. The major objective of this report is to review the concept of Mobile Mapping System and GPS/INS supported direct platform orientation (DPO) in particular, as well as their evolution since early 1990s, with a special emphasis on the research and development carried out in this area at the Ohio State University. A short review of the inertial navigation concept is given, and a notion of GPS/INS (inertial navigation system) integration is also presented. The concept of direct georeferencing is also explained and compared to the traditional aerotriangulation (AT) method of image geo-registration, and the importance of multi-sensor system calibration is discussed, including its impact on the positioning accuracy. Some examples of currently attainable navigation performance, based on the OSU-developed Airborne Integrated Mapping System (AIMS) and the land-based system for highway mapping are discussed, and future perspectives of MMS are presented. Although MMS may be, in general, associated with land-based applications, the concept of airborne mapping (remote sensing) based on DPO is also discussed here, primarily due to the fact that airborne positioning and orientation systems based on GPS/INS integration are based on similar hardware and software designs, and clearly evolved from the traditional airborne mapping as a consequence of the advent of a high-accuracy GPS/INS systems. Thus, the DPO facilitated through GPS/INS fusion is a common denominator for the modern land-based and airborne mapping, which often times involves multiple imaging sensors to achieve higher accuracy, and data complementarity and redundancy