Method and Implementation of Improving the Pointing Accuracy of an Optical Remote Sensor Using a Star Sensor

Abstract

Based on the analysis of the pointing accuracy of the optical sensor in a star sensor, this paper introduces the geometric accuracy of the star sensor as an external orientation element that affects the optical remote sensing image and analyzes the characteristics of the installation method of the star sensor in different optical remote sensors. The key factors affecting the pointing accuracy of the star sensor are considered, and the geometrical accuracy of the image is improved by analyzing the installation method of the star sensor, the star sensor bracket design, and the star sensor thermal control component. Achievable measures are made, and the pointing stability of the star sensor is verified through a ground test and by measuring the temperature fluctuations of the orbiting sensor. Through ground testing and on-orbit testing, the star sensor bracket has a temperature fluctuation of <1 ℃ in one photography cycle, and the star sensor's attitude error around the axis is less than 5", so the uncontrolled geometric positioning accuracy of the image product can be obtained as 11.4 m (rms).

Representation and Reasoning of Three-Dimensional Spatial Relationships Based on R5DOS-Intersection Model Representation and Reasoning Based on R5DOS Model

“…At present, the relationships between objects in the 3D space are mostly solved by compound reasoning. e common approaches of compound reasoning include the compound reasoning of directional and topological relationships [14,15] and the compound reasoning of directional and distance relationships [16]. Liu et al [17] designed a 3D improved composite spatial relationship model (3D-ICSRM) in a large-scale environment and proposed a reasoning algorithm to solve that model.…”