NTRS - NASA Technical Reports Server

Back to Results
assessment of modis on-orbit calibration using a deep convective cloud techniqueThe MODerate Resolution Imaging Spectroradiometer (MODIS) sensors onboard Terra and Aqua satellites are calibrated on-orbit with a solar diffuser (SD) for the reflective solar bands (RSB). The MODIS sensors are operating beyond their designed lifetime and hence present a major challenge to maintain the calibration accuracy. The degradation of the onboard SD is tracked by a solar diffuser stability monitor (SDSM) over a wavelength range from 0.41 to 0.94 micrometers. Therefore, any degradation of the SD beyond 0.94 micrometers cannot be captured by the SDSM. The uncharacterized degradation at wavelengths beyond this limit could adversely affect the Level 1B (L1B) product. To reduce the calibration uncertainties caused by the SD degradation, invariant Earth-scene targets are used to monitor and calibrate the MODIS L1B product. The use of deep convective clouds (DCCs) is one such method and particularly significant for the short-wave infrared (SWIR) bands in assessing their long-term calibration stability. In this study, we use the DCC technique to assess the performance of the Terra and Aqua MODIS Collection-6 L1B for RSB 1 3- 7, and 26, with spectral coverage from 0.47 to 2.13 micrometers. Results show relatively stable trends in Terra and Aqua MODIS reflectance for most bands. Careful attention needs to be paid to Aqua band 1, Terra bands 3 and 26 as their trends are larger than 1% during the study time period. We check the feasibility of using the DCC technique to assess the stability in MODIS bands 17-19. The assessment test on response versus scan angle (RVS) calibration shows substantial trend difference for Aqua band 1between different angles of incidence (AOIs). The DCC technique can be used to improve the RVS calibration in the future.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Mu, Qiaozhen
(Science Systems and Applications, Inc. Lanham, MD, United States)
Wu, Aisheng
(Science Systems and Applications, Inc. Lanham, MD, United States)
Chang, Tiejun
(Science Systems and Applications, Inc. Lanham, MD, United States)
Angal, Amit
(Science Systems and Applications, Inc. Lanham, MD, United States)
Link, Daniel
(Science Systems and Applications, Inc. Lanham, MD, United States)
Xiong, Xiaoxiong
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Doelling, David R.
(NASA Langley Research Center Hampton, VA, United States)
Bhatt, Rajendra
(Science Systems and Applications, Inc. Hampton, VA, United States)
Date Acquired
April 17, 2017
Publication Date
September 19, 2016
Publication Information
Publication: SPIE Proceedings, Earth Observing Systems XXI
Volume: 9972
Subject Category
Meteorology and Climatology
Earth Resources and Remote Sensing
Report/Patent Number
Meeting Information
SPIE Optics and Photonics 2016(San Diego, CA)
Distribution Limits