A Study of NOAA-20 VIIRS Band M1 (0.41 µm) Striping over Clear-Sky Ocean

Details

• Journal Title:
  Remote Sensing
• Personal Author:
  Wang, Wenhui ; Cao, Changyong ; Blonski, Slawomir ; Shao, Xi
• NOAA Program & Office:
  NESDIS (National Environmental Satellite, Data, and Information Service) ; CISESS (Cooperative Institute for Satellite Earth System Studies) ; STAR (Center for Satellite Applications and Research)
• Description:
  The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the National Oceanic and Atmospheric Administration-20 (NOAA-20) satellite was launched on 18 November 2017. The on-orbit calibration of the NOAA-20 VIIRS visible and near-infrared (VisNIR) bands has been very stable over time. However, NOAA-20 operational M1 (a dual gain band with a center wavelength of 0.41 µm) sensor data records (SDR) have exhibited persistent scene-dependent striping over clear-sky ocean (high gain, low radiance) since the beginning of the mission, different from other VisNIR bands. This paper studies the root causes of the striping in the operational NOAA-20 M1 SDRs. Two potential factors were analyzed: (1) polarization effect-induced striping over clear-sky ocean and (2) imperfect on-orbit radiometric calibration-induced striping. NOAA-20 M1 is more sensitive to the polarized lights compared to other NOAA-20 short-wavelength bands and the similar bands on the Suomi NPP and NOAA-21 VIIRS, with detector and scan angle-dependent polarization sensitivity up to ~6.4%. The VIIRS M1 top of atmosphere radiance is dominated by Rayleigh scattering over clear-sky ocean and can be up to ~70% polarized. In this study, the impact of the polarization effect on M1 striping was investigated using radiative transfer simulation and a polarization correction method similar to that developed by the NOAA ocean color team. Our results indicate that the prelaunch-measured polarization sensitivity and the polarization correction method work well and can effectively reduce striping over clear-sky ocean scenes by up to ~2% at near nadir zones. Moreover, no significant change in NOAA-20 M1 polarization sensitivity was observed based on the data analyzed in this study. After the correction of the polarization effect, residual M1 striping over clear-sky ocean suggests that there exists half-angle mirror (HAM)-side and detector-dependent striping, which may be caused by on-orbit radiometric calibration errors. HAM-side and detector-dependent striping correction factors were analyzed using deep convective cloud (DCC) observations (low gain, high radiances) and verified over the homogeneous Libya-4 desert site (low gain, mid-level radiance); neither are significantly affected by the polarization effect. The imperfect on-orbit radiometric calibration-induced striping in the NOAA operational M1 SDR has been relatively stable over time. After the correction of the polarization effect, the DCC-based striping correction factors can further reduce striping over clear-sky ocean scenes by ~0.5%. The polarization correction method used in this study is only effective over clear-sky ocean scenes that are dominated by the Rayleigh scattering radiance. The DCC-based striping correction factors work well at all radiance levels; therefore, they can be deployed operationally to improve the quality of NOAA-20 M1 SDRs.
• Source:
  Remote Sensing, 17(1), 74
• DOI:
  https://doi.org/10.3390/rs17010074
• ISSN:
  2072-4292
• Format:
  pdf
• Publisher:
  MDPI AG
• Document Type:
  Journal Article
• Funding:
  Grant no. NA19NES4320002 ; Grant no. NA24NESX432C0001
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:9aa7ed69769840b1f474c6da470499a1f50722b3281be9dc4ddbd59c831fe2bab025514f274f75a9f1c77e570685ce008eed58da9597a68f735e1e7789b07aad
• Download URL:
  https://repository.library.noaa.gov/view/noaa/72103/noaa_72103_DS1.pdf
• File Type:
  [PDF - 6.98 MB ]