Precision and Characteristics of Satellite Spatial Quality Estimators’ Measurement Using an Edge Target Imaged with KOMPSAT-3A

Abstract

After the launch of a high-resolution remote sensing satellite, representative spatial quality estimators (RER, FWHM, MTF50, MTFA) are measured from images taken of ground Edge targets. In this work, the best spatial quality estimator is proposed by quantitatively comparing and analyzing the precision between the Relative Edge Response (RER), the Full Width at Half Maximum (FWHM), the MTF value at the Nyquist frequency (MTF50), and the MTF Area between 0 and the Nyquist frequency (MTFA). While the basic method for the measurement of spatial quality estimators on Edge targets is already well established, this work summarizes and explains the uncertain factors and problems in the measurement procedure that affect the accuracy and precision of spatial quality estimators. It also considers how to improve the precision of spatial quality estimators during the measurement procedure. The contents and results of this work were discussed by various satellite development organizations in the Geo-Spatial Working Group within CEOS WGCV IVOS from 2012 to 2019, and the Edge target Spatial quality Measurement Python code (ESMP) was developed in 2019 to reflect the findings of this workshop. Using 483 Edge targets from worldwide images taken by KOMPSAT-3A, which has been in operation since 2017, the results obtained via ESMP show that the precision levels of RER, FWHM, and MTFA are approximately three to four times higher than that of MTF50 when comparing the Coefficient of Variance (CV) statistics. This is the first statistical comparison of spatial quality estimators using 7 years of ground Edge target imagery from a single satellite of KOMPSAT-3A.

Keywords

• satellite spatial quality
• MTF
• RER
• FWHM
• Edge target
• precision