Integrated GPS-aided Inertial Lidar and Optical Imaging Systems for Aerial Mapping

High-resolution airborne Lidar and optical imaging systems with onboard data collection based on the Global Positioning System (GPS) and inertial navigation syste ms (INS) technology may offer the means to gather accurate topographic map information. As a follow-up to earlier investigations, in May 2005 an airborne integrated GPS-aided inertial Lidar and optical imaging system was used to collect data over the southern San Andreas Fault. A major thrust of this paper is to compare the positional accuracy of Lidar and optical imaging system points obtained from these investigations. Presented herein are the collective results of those horizontal and vertical accuracy measurements and concluding remarks about their potential for aerial mapping in Antarctica. The marked change in relief of the Grand Canyon is similar to the Dry Valleys of Antarctica. These changes provide an excellent test for measuring the potential of the GPS-aided inertial Lidar and optical imaging systems for aerial mapping. The San Andreas Fault poses a major earthquake hazard to the greater metropolitan areas in southern California and Lidar and optical imaging systems could provide information vital to post -disaster response. All together, these findings of positional accuracy yield important information on a new approach for aerial mapping in Antarctica and other remote areas of the world. Introduction Many applications of geospatial data, especially in remote areas, are realized more efficiently by direct georeferencing using an airborne integrated system comprised of GPS receiver and inertial navigation system components. Direct georeferencing (DG) is the enabling technology for airborne Light Detection and Ranging (Lidar) and electro-optical imaging systems. Crucial issues to the direct georeferencing of Lidar and optical imaging is the positional accuracy and reliability achievable by the Lidar and digital camera integrated system. Numerous documented GPS/INS -related field tests have been conducted over the years (Cramer, 1999; Cramer, Stallmann, and Haala, 2000). These tests, flown over mostly flat __________________________ Any use of trade, product, or firm nam es is for descriptive purposes only and does not imply endorsement by the U.S. Government terrain, were evaluated by private and public institutions to meet National Mapping Accuracy Standards (NMAS) and American Society of Photogrammetry and Remote Sensing (ASPRS) accuracy standards for large -scale mapping. However, tests flown over steep terrain resulted in higher than normal vertical positional bias that did not meet positional accuracy standards for large -scale mapping (Cramer, 1999; Colomina, 1999; Greening and others, 2000; and, Sanchez and Hothem, 2002). Significant accuracy improvements have come about when operating in a multi -receiver configuration (Shi, 1994, Raquet, 1998, Bruton, Mostafa, and Scherzinger, 2001, Sanchez, 2004: Sanchez and Hudnut, 2005). The objective of this study, funded by the National Science Foundation and the U.S. Geological Survey, is to compare the positional accuracy of the Lidar and optical systems data obtained from previous investigations and examine the potential of airborne integrated GPS -aided inertial Lidar and optical imaging systems for aerial mapping in Antarctica. Test Areas Grand Canyon The first test conducted in July of 2003 lies in the northernmost part of the Grand Canyon also referred to as Glen Canyon (Sanchez, 2004). The marked change in relief of the canyon are similar to the Dry Valleys of Antarctica and provide an excellent test for measuring the potential of the GPS -aided inertial Lidar and optical imaging systems aerial mapping (figure 1).