Geometric Correction Of Airborne Hyperspectral Images By POS/DG Data

Geometric correction of airborne hyperspectral image is important to image's quality. Usually, traditional methods, such as registration by ground control points or geometric correction by GPS, need too much ground work and cost a lot. They are not feasible well.Geometric correction of hyperspectral image by POS/DG (Position and Orientation System / Direct Georeferencing) data is the first attempt in China now. POS/DG has much information of situation and posture, such as absolute position coordinates (x,y,z) and rotate elements. During airborne imaging, every line of hyperspectral image has its own POS/DG record. Every pixel's ground coordinates and ground size can be computed out by longitude > latitude N altitude, platform heading^ rolK pitch and velocity of each axis. Then every pixel of raw image is resampled to get the new corrected image.First chapter: The development of hyperspectral remote sensing technology and today's condition and development of airborne hyperspectral image* geometric correction.Second chapter: The structure and work principle of POS/DG; physical meaning of each POS/DG parameter.Third chapter: Introducing the structure and work principle of push-broom scan imager with PHI; introducing the method of PHI image's geometric correction.Forth chapter: Introducing the structure and work principle of optical-mechanical scan imager with OMIS; introducing the method of OMIS image's geometric correction.Fifth chapter: The flow of raw image-^geometric correction-^map.Sixth chapter: The software of POS/DG geometric correction.There are tow problems in the procession of geometric correction: 1 how to compute out each pixel's coordinates by POS/DG parameters precisely; This is in the field of airborne photogrammetry. 2 how to choose the method of resmapling in order to get the best result; This is in the field of image manipulation. POS/DG data describes the situation and posture of image line precisely. Pretty process can mostly reduce the geometric distortion and clear the image blurring. The most important advantage of using POS/DG data to correct remote sense images is that this way needs not ground investigation. Consequently, it can save a lot of money, complicated work .It is the necessary way in today's efficient society.