Estimation of Modulation Transfer Function (MTF) of VNREDSat-1 satellite for image quality assessment by using the permanent test site
- Authors: Ngoc Minh Nguyen 1, 2*, Anh Van Tran 2, Tuan Van Nghiem 3, Huy Xuan Chu 1, Thao Phuong Thi Do 2
- Organ:1 Space Technology Institute, Vietnam Academy of Science and Technology, Vietnam
2 Faculty of Geomatics and Land Administration, Hanoi University of Mining and Geology, Vietnam
3 Division of Science and International Relations, Department of National Remote Sensing, Vietnam
- Keywords: Bãi thử,Chất lượng ảnh,MTF,VNREDSat-1.
- Received: 18th-Sept-2020
- Accepted: 9th-Jan-2021
- Available online: 28th-Feb-2021
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.
. Francoise Viallefont-Robinet, Dominique Léger, (2010). Improvement of the edge method for on-orbit MTF measurement. Optics Express Vol.18, No.4, 3531-3545.
. Glen D. Boreman, (2001). Modulation Transfer Function in Optical and Electro-Optical Systems. Published by SPIE-The International Society for Optical Engineering. USA, 123 pages.
. Léger, D., Viallefont, F., Déliot, P., Valorge, C., (2004). On-orbit MTF assessment of satellite cameras, In Stanley A.Morain & Amelia M. Budge (Editors) ISPRS Book Series-Volume 2. Proceedings of the International Workshop on Radiometric and Geometric Calibraiton. Post-lauch Calibration of Satellite Sensors, 2-5 December 2003, Gulfport, Mississippi, USA, 67-77.
. Nghiêm Văn Tuấn, (2017). Nghiên cứu phương pháp kiểm định và hiệu chỉnh chất lượng ảnh viễn thám quang học của Việt Nam. Đề tài cấp bộ Tài nguyên và Môi trường, thuộc chương trình Khoa học và Công nghệ cấp Bộ, mã số TNMT2016.08.02.
. Philippe Blanc, Lucien Wald, (2009). A review of earth-viewing methods for in-flight assessement of modulation transfer function and noise of optical spaceborne sensors. Working paper. HAL archives-ouvertes.