ORIENIING FORMOSAT-2 IMAERY BY CONTROL PATCHES

摘要

The FORMOSAT-2 imagery is able to render 2m ground resolution in panchromatic mode at nadir direction and is of high potential to produce up to 1:10000 maps in theory. This research investigates the geometric transformation models, including bundle adjustment, polynomial transformation, parallel perspective model and rational function model to construct the object-to-image relationship of FORMOSAT-2 imagery by employing control patches. The test area of the Level 1A FORMOSAT-2 imagery is in Nantsu, Kaohsiung and the control patches with positioning accuracy of 0.2～0.5m in the object space were provided by China Engineering Consultant Inc. The primary experiment results show that the stability of the sensor, the number of control patches, and the chosen geometric transformation model would mostly affect the accuracy of object-to-image transformation. With an adequate number (more than 100) of control points well distributed in the study area, the positioning accuracy in image space is reported to around 0.5～0.7 pixels when using 3rd order rational function model as well as bundle adjustment with self calibration.