Effects of IMU/INS quality on horizontal geometry accuracy of the ALOS PALSAR and WorldView-2 images

Abstract

Nowadays Photogrammetry and Remote Sensing technology is growing rapidly. Various types of sensors and supporting instruments also have many advantages, one of them is IMU/INS. This instrument plays an important role in image geometry stability, especially in rotation parameters. IMU/INS quality has an effect on determining the horizontal geometry accuracy of satellite images. The data used in this study are ALOS PALSAR and WorldView-2. The study area is located on Rote Island, Indonesia. This study aims to determine the quality effects of IMU/INS influencing the geometric quality of ALOS PALSAR and WorldView-2 satellite imagery. The way to do this is to compare the coordinates on the same object in the ALOS PALSAR and WorldView-2 images. Both of these images are in orthoimage condition. Then reference field is carried out because the two images differ in spatial resolution. ALOS PALSAR imagery is used as reference field because it has a lower spatial resolution. After that, checking at 10 points on the same object in both images. The results obtained in the form of values and direction of object shift in both orthoimage. The pattern of the second shift in orthoimage can be seen. IMU/INS on WorldView-2 is better than ALOS PALSAR when see the shift points. The shift in ALOS PALSAR is systematic, while the shift in WorldView-2 is more random. Fixed incidence angles cause the pattern of systematic shifts but cause high bias or low accuracy in horizontal geometry. The horizontal geometric quality is influenced by the type of IMU/INS used. ALOS PALSAR images use IMU/INS type 2 (tactical) while WorldView-2 images use IMU/INS type 1 or navigational. This IMU/INS quality needs to be considered for the utilization of satellite imagery on certain scale and certain survey mapping applications and each orthoimage has accuracy with certain tolerance.