# Research into Image Point Positioning Compensation of a High-Orbit Thermal Infrared Staring Camera
###### Abstract  
The sight of the high-orbit thermal infrared staring camera is concentrated and sensitive to temperature changes, and therefore its image point positioning is key to ensuring the geometric quality of the thermal infrared staring image and eliminating the errors of the imaging system in orbit. According to the geometric imaging characteristics of the high-orbit thermal infrared staring camera, internal and external positioning compensation models are proposed in this paper based on the two-dimensional pointing angle of temperature change, and four kinds of experimental schemes of image point positioning compensation are designed. The experimental results show that the method proposed in this paper has a good compensation effect on the image point positioning error. area array camera; image point positioning; error compensation; two-dimensional pointing angle +
Footnote †: journal: _aciences_  
0000-0001-6000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-000000-00000-000000-000000-000000-00000-00000-000000-00000-000000-000000-000000-000000-000000-000000-0000000-000000-0000000-0000000-0000000-00000000-0 imaging of the geosynchronous orbit early warning satellite. The on-orbit imaging process of the high-orbit camera, similar to other types of optical cameras, is actually a process in which multiple on-board loads such as attitude measurement, orbit measurement, and time synchronization measurement work together. In this process, there are various external measurement results errors. In addition, due to the complex operating environment of the geosynchronous satellite, the camera itself also has a certain degree of internal distortion. Therefore, the geometric processing of the high-orbit image is very important. In recent years, high-precision geometry processing technologies for middle and low orbit satellites and aerial images have become more developed [2], including geometric imaging models, in-orbit geometric calibration models and sensor rectifying models [3; 4; 5]. [PERSON], [PERSON] [6] developed the line-of-sight (LOS) algorithm and control flow and image motion compensation based on the imaging optical path. [PERSON] [7] and others conducted an in-depth exploration on the sensor laboratory calibration and the in-orbit rectifying of the MOMS-2P satellite, and for each CCD array they built a corresponding in-orbit geometric rectifying model, mainly correcting the internal geometric distortion of the camera, including the deviation of the image principal point, the deviation of the focal length, and the bending and rotating of the CCD, and finally a uniform solution was obtained through the method of bundle adjustment. [PERSON] [8] and others carried out the in-orbit geometric calibration of a SPOTS HRG camera and HRS camera, respectively, through high-precision 50 cm high-resolution reference data provided by the calibration site on the ground. They, respectively, used the calibration model of quintic polynomial fitting to compensate for the errors in the directions alongside the orbit and perpendicular to the orbit, and this could ultimately reduce the distortion error inside the camera to less than 0.1 pixel. [PERSON], [PERSON] [9] established different positioning models and analyzed the calculation principle of the aerial remote sensing image positioning algorithm. [PERSON] [10] and others set 15 additional parameters according to the characteristics of India's IRS-1C satellite camera and verified the impact of each additional parameter on the positioning accuracy by designing experiments with different combinations of additional parameters. Japan's ALOS [11] satellite used the self-rectifying regional network adjustment with additional parameters to carry out the overall calibration.