초소형 군집 위성 1호 영상 데이터 위치 정확도 평가

The micro-satellite constellation system was developed to precisely monitor the Korean Peninsula and surrounding waters and to respond to disasters and security needs. The first satellite was launched on April 24, 2024. Weighing less than 100 kg, it captures 1-meter resolution black-and-white images and 4-meter resolution color images. Since small satellites have lower sensor reliability compared to large satellites, improving geometric correction and positional accuracy of the imagery is even more critical. In this study, the positional accuracy of image data collected by the first micro-satellite after an initial calibration period was evaluated. To efficiently assess the positional accuracy of a large volume of data through automated methods, high-resolution aerial images were used to extract reference points, and automated image matching techniques were applied to generate a substantial number of reference points. The errors in image coordinates at these reference points were measured, and error patterns across the entire image were analyzed. Experimental results showed 10~20 pixels of positional errors were reported without control points but 2 pixels level of accuracy could be obtained with RPCs (Rational Polynomial Coefficients) affine-based bias compensation. However, local errors should be compensated for better positional accuracy.