Estimation of Modulation Transfer Function (MTF) of VNREDSat-1 satellite for image quality assessment by using the permanent test site

  • Ngoc Minh Nguyen Vietnam Academy of Science and Technology, Hanoi, Vietnam
  • Anh Van Tran Hanoi University of Mining and Geology, Hanoi, Vietnam
  • Tuan Van Nghiem Department of National Remote Sensing, Hanoi, Vietnam
  • Huy Xuan Chu Vietnam Academy of Science and Technology, Hanoi, Vietnam
  • Thao Phuong Thi Do Hanoi University of Mining and Geology, Hanoi, Vietnam
Keywords: Image quality, MTF, Test site, VNREDSat-1

Abstract

MTF is a factor in evaluating image quality with respect to the contrast and sharpness of the payload, thus directly related to spatial resolution. Therefore, ensuring image quality is an important task, especially for small satellites with high spatial resolution. This study uses the slanted-edge method for the artificial permanent test site and VNREDSat-1 image data with spatial resolution of panchromatic band as 2.5 m to make an MTF value estimate. The MTF value during 5 years of operation averages about 0.2 compared to the threshold as 0.08 (for the test site at Salon de Provence, France, the MTF value ranged from 0.16÷0.27 in across-track direction and 0.16÷0.25 in along-track direction; and at the Buon Ma Thuot test site, these values were 0.16÷0.23 and 0.20÷0.24, the reflectivity of these two test sites are similar), proving that image quality is guaranteed throughout the design life of the satellite; moreover, they are also the basis for Vietnam to finalize regulations on validation and calibration of optical satellite systems in the future when we have own test site.

References

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Published
2021-02-28
Section
Applied sciences