Spatial Resolution Evaluation Method Based on Edge Characteristics

The most common way to evaluate spatial resolution is visual method, but it is time-consuming, laborious, easily affected by evaluators and output environment, and resolution targets must be arranged. In practical applications, it is difficult to obtain remote sensing images containing resolution targets. Therefore, how to use images without resolution targets but with typical features (edge, linear) to develop a practical objective detection method of spatial resolution has practical significance and application requirements. To solve this problem, the basic concepts and calculation methods of several parameters: FWHM, EQW, 2σ width, ESW, R0.02, R0.05, etc., closely related to the spatial resolution and often used to reflect the payload’s ability to reproduce details, are analyzed by using edge target. Through simulation experiments and real data verification, the relationship between these parameters and spatial resolution is analyzed and compared. It is found that these parameters are linearly related to standard deviation of the MTF curve (σMTF), and their change laws are basically consistent with the visual resolution. However, the result is far from the actual visual resolution. A new spatial resolution evaluation method based on edge characteristics is proposed in this paper. The analysis results show that there is a certain linear relationship between σMTF of the imaging system and its spatial resolution. The spatial resolution calculated by this method is consistent with the visual results, the deviation is small, and the correlation can reach 86.12%.