SPOT衛星HRV画像の空間分解能の評価

抄録

Remotely sensed data from satellite which are LANDSDAT Thematic Mapper and SPOT High Resolution Visible images can provide very useful information. However, the satellite image usually includes several kinds of distortions. To utilize them in high performance is necessary of the high quality image.
One of parameters for an image quality estimation is a spatial resolution for a sensor aperture characteristics.
This paper discusses the experiment to determine the actual spatial resoultion of an HRV image gathered by the linear array sensors carried on SPOT-1 satellite which was launched in 1986 and the anisotropic degradation of resolution due to the dwell time of sensor and the motion of satellite.
The spatial resolution are derived from a Line Spread Function which can be obtained by using a scene structure such as banks of field edges.
LSF (or Point Spread Function) is calculated by the differential of function which indicates a gray level of the edges.
In this paper, the spatial resolution is defined by the width at 50% fall point of PSF peak. Consequently, The numerical results of the spatial resolution are affected by the atmosheric effects, and the resolution in the along-track direction is worse 15.9% than that in the across-track direction. The linear array sensed image includes the degradations of image quality due to the sensor aperture characteristics and satellite motion. Therefore, The design of filters for image restortion are necessary to consider the direction.
by Y. Seto, and E. Nishijima