On-Orbit Geometric Calibration Model and Its Applications for High-Resolution Optical Satellite Imagery

Abstract

On-orbit geometric calibration is a key technology to guarantee the geometric quality of high-resolution optical satellite imagery. In this paper, we present an approach for the on-orbit geometric calibration of high-resolution optical satellite imagery, focusing on two core problems: constructing an on-orbit geometric calibration model and proposing a robust calculation method. First, a rigorous geometric imaging model is constructed based on the analysis of the major error sources. Second, we construct an on-orbit geometric calibration model through performing reasonable optimizing and parameter selection of the rigorous geometric imaging model. On this basis, the calibration parameters are partially calculated with a stepwise iterative method by dividing them into two groups: external and internal calibration parameters. Furthermore, to verify the effectiveness of the proposed calibration model and methodology, on-orbit geometric calibration experiments for ZY1-02C panchromatic camera and ZY-3 three-line array camera are conducted using the reference data of the Songshan calibration test site located in the Henan Province, China. The experimental results demonstrate a certain deviation of the on-orbit calibration result from the initial design values of the calibration parameters. Therefore, on-orbit geometric calibration is necessary for optical satellite imagery. On the other hand, by choosing multiple images, which cover different areas and are acquired at different points in time to verify their geometric accuracy before and after calibration, we find that after on-orbit geometric calibration, the geometric accuracy of these images without ground control points is significantly OPEN ACCESS

A Knowledge-Based Search Strategy for Optimally Structuring the Terrain Dependent Rational Function Models

“…In the second step, the maximum number of the search cases is equal to 1050, which can be calculated from Equation (6). In the first step, the maximum number of the search cases is equal to 4095, which can be calculated using Equation (4).…”

“…The search space of the first step is illustrated in Figure 3. In the first step, the maximum number of the search cases is equal to 4095, which can be calculated using Equation (4).…”

“…Accurate image geo-referencing is an important pre-processing step for this analysis [1], in order to avoid errors due to misregistration [2], because, even small geometric errors could have a significant effect on retrieval of subsequent information [3]. Most modern satellite imagery is supplied with a sufficient and reliable Rational Polynomial Coefficients (RPC) [4], and sub-pixel geo-referencing accuracies can be achieved by bias-compensating these coefficients using a few Ground Control Points (GCP) [5,6]. However, old archive imagery are a main part of the data sources for multi-temporal analysis.…”

Inner FoV Stitching of Spaceborne TDI CCD Images Based on Sensor Geometry and Projection Plane in Object Space

“…In addition, since GPS measures the position of GPS phase center, and attitude sensor measures the orientation from the satellite body-fixed coordinates system and the orbit coordinates system, or from the star sensor to the ground in the J2000 inertial frame, to acquire the camera position and attitude of the main optical axis, the data measured by GPS and star sensor need to be transformed to the position and orientation of the camera [8,11,25,26]. If we ignore the offset vector of GPS phase center in the satellite body-fixed coordinates system, the lever arm matrix between camera frame and satellite platform, as well as the influence of atmospheric refraction, the rigorous geometric sensor model of a spaceborne TDI CCD image can be then expressed in Equations (1) or (2) …”

“…is the rotation matrix between the orbit coordinates system and J2000 inertial coordinates system. are the pointing angles of a certain CCD detector, which represent the geometric relation of each detector ray in the camera coordinates system [8,12,[25][26][27]. In practice, regarding the auxiliary data provided, the rigorous geometric sensor model in the form of Equation (1) is most often used in ZY-3 satellite [8,16,25,26], while Equation (2) will be suited for ZY-1 02C satellite [10][11][12]26].…”