The spatial quality (RER, FWHM, MTF50, and MTFA) of an on-orbit high-resolution Earth observation satellite was statistically assessed using edges extracted from natural targets in urban imagery, rather than from a ground-based artificial edge target (Edge target). A total of 8414 edge patches were automatically extracted from Natural Targets (NT) in 24 images acquired over 11 cities worldwide by KOMPSAT-3A. The spatial quality results derived from NT edges were compared with those obtained from an Edge target in terms of accuracy and precision. The averaged spatial quality values were nearly identical between the two approaches. However, the coefficient of variation (CV), used to quantify precision, was approximately two times higher for NT edges. Despite this lower precision, NT-based assessment provides substantial operational advantages. While 549 Edge target acquisitions over eight years yielded only 1098 usable edge images, a single acquisition over Las Vegas produced 366 NT edge images. These findings indicate that statistically reliable spatial quality estimates with comparable accuracy can be achieved within a single day using abundant NT edges, without the need to construct and maintain dedicated Edge targets.
Lee et al. (Mon,) studied this question.