Abstract
The present paper proposes an accurate geometric correction method for AVHRR data. Our previous work has proposed a method, which uses the bilinear interpolation for speeding up geometric correction of AVHRR data, but there is still tiny residual error after geometric correction only using the orbital information TBUS. GCP method is the general method for improving the accuracy of geometric correction. The tendency of each orbital element and satellite reported time (satellite internal clock) for the GCP's residual error is analyzed by curve fitting method as a polynomial expression. The standard regularization method is introduced to solve the reverse problem from the GCP's residual errors to the variation of each orbital element. The residual errors in line direction and pixel direction from GCP process are smoothly changed, therefore, two-dimensional surface spline is applied to the smooth-constrained stabilizer. However, the solution from the regularization method is not the globally optimal one but the locally optimal one sometimes. Here, the orbital information TBUS is analyzed to decide the correction order of orbital elements. From this correction order, an algorithm with the polynomial expressions can be used to estimate the variation of each orbital element and satellite reported time from the GCP's residual error, when the locally optimal solution meets. Finally, some experimental results are shown to verify the proposed method, and we will conclude our proposed geometric correction method.
