Satellite Imaging Pointing Correction for Orbit Prediction Drift
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Solution Overview
Problem
The limited performance of orbit propagators leads to errors in predicting satellite orbits, resulting in inaccuracies in satellite image capture, with a positional error of approximately 200 meters per day, which can cause misalignment with the intended target region.
Innovation Solution
A method and apparatus that corrects the satellite's posture by calculating a posture correction angle based on the difference between satellite-based and ground-based predicted orbits, using a receiver, estimator, and controller to ensure accurate image acquisition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ground-based orbit propagator is used to predict satellite position, then image acquisition planning can be performed, but positional error accumulates approximately 200 meters per day
Solution Approach 1:
The patent implements feedback by comparing the ground-based predicted orbit with the satellite-based predicted orbit, calculating the difference therebetween, and using this difference to generate posture correction commands. This closed-loop feedback mechanism continuously compensates for the 200 meters per day positional drift, maintaining accurate image acquisition capability over extended operational periods.
Solution Approach 2:
The patent replaces reliance on purely ground-based mechanical/orbital mechanics prediction with a dual-system approach that incorporates satellite-based orbit propagation. This substitution introduces a second, independent prediction mechanism that operates from space, allowing cross-validation and correction of ground-based predictions without requiring complex ground tracking infrastructure.
2Device complexity
If satellite posture is not corrected, then simple ground-based prediction can be used, but image capture position becomes inaccurate
Solution Approach 1:
The patent introduces an intermediary correction mechanism that acts as a bridge between ground-based prediction and satellite execution. The posture correction command, generated from orbit difference calculation, serves as an intermediary element that translates prediction discrepancies into actionable adjustments, enabling accurate image capture without requiring complete replacement of the ground-based prediction system.
3Measurement precision
If satellite-based orbit propagator is used on the satellite, then actual position can be tracked, but calculation of posture correction is required
Solution Approach 1:
The patent segments the orbit prediction and correction functionality into distinct modular components: ground-based orbit propagator, satellite-based orbit propagator, orbit difference calculator, and posture correction command generator. This segmentation allows each component to perform its specialized function independently, simplifying the overall system architecture while achieving high positioning accuracy through coordinated operation of these modular segments.
Data Source
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AI summary
A method and a correction device for correcting satellite image acquisition positioning are disclosed. A method for correcting satellite image acquisition positioning, according to one embodiment of the present invention, can comprise the steps of: receiving a desired photographing satellite location (PDesired) of a satellite and a planned terrestrial photographing time (TImaging) from a terrestrial-based orbit propagator in response to an image acquisition command; estimating a predicted satellite location (Predicted) where the satellite is located at the planned terrestrial photographing time (TImaging); calculating a positioning correction angle (dθ) for the satellite at the predicted satellite location (PPredicted) by using the desired photographing satellite location (PDesired); and after correcting the positioning of the satellite according to the positioning correction angle (d9), performing control so as to acquire an image from the satellite.