Cramer 1 ( 1 ) GPS / INS Integration

R m p x p y p f p Cramer 1 (1) ABSTRACT One of the major tasks in the evaluation process of remotely sensed data is the determination of the exterior orientation to relate the recorded data to a geodetic reference coordinate frame. This process is called georeferencing and is very close to the concept of inverse photogrammetry realized indirect via the use of ground control. With the availability of the Global Positioning System GPS and the decreasing costs of inertial navigation systems (INS) the direct measurement of the position and attitude parameters of the sensor stations during the time of exposure becomes feasible. Hence, the exterior orientation is independent of any ground control today. After a brief discussion of the mathematical model for georeferencing this paper will focus on the different approaches for direct georeferencing using integrated GPS/INS systems. Due to the complexity of this topic, only the basic facts without detailed description of the mathematical background are discussed. To motivate the integration approach, the major characteristics of the GPS and INS as stand-alone units are described and their complementary error behaviour is pointed out. Then the different levels of integration are given. Finally, the high potential of GPS/INS integrated systems is demonstrated reviewing the results of two airborne tests.