An exposition on the solar diffuser degradation non-uniformity effect for SNPP VIIRS and Terra/Aqua MODIS

The use of a specially manufactured solar diffuser (SD) is at the heart of the on-orbit calibration of the reflective solar bands (RSBs) for many important satellite sensors. This includes the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite, and the Moderate-resolution Imaging Spectroradiometer (MODIS) onboard the Terra and Aqua satellites. Within the current standard calibration procedure is an implicit assumption of an idealized degradation of SD in which its angular dependence remains the same functional form with the overall degradation level characterized by a single parameter, the SD degradation factor. This permits the measurement of the SD reflectance performance, measured by the SD stability monitor (SDSM) at a given outgoing angle with respect to the SD, to be used as a valid substitute for the SD reflectance performance toward the RSB direction that is at a different outgoing angle. Recent in-depth studies have uncovered evidence to contradict this assumption, and due to this difference in the outgoing angles between the RSBs and SDSM, the RSB calibration coefficients inherit growing bias. In this exposition, we will explicitly show the evolving angular dependence in SD degradation for SNPP VIIRS and Terra/Aqua MODIS. By examining the angular dependence of the available detector response within each calibration event we are able to build a historical trend clearly demonstrating evolving angular dependence. We refer to this phenomenon as the “SD degradation nonuniformity effect”. Our finding lays out a very basic mismatch between the use of the SD and the current official RSB calibration methodology that will be an important issue to be addressed.

[1]  Junqiang Sun,et al.  Radiometric evaluation of the SNPP VIIRS reflective solar band sensor data records via inter-sensor comparison with Aqua MODIS , 2016, Optical Engineering + Applications.

[2]  Xiaoxiong Xiong,et al.  Multiyear On-Orbit Calibration and Performance of Terra MODIS Reflective Solar Bands , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[3]  Menghua Wang,et al.  VIIRS reflective solar bands on-orbit calibration and performance: a three-year update , 2014, Asia-Pacific Environmental Remote Sensing.

[4]  J. Sun,et al.  Analysis of MODIS solar diffuser screen vignetting function , 2005, SPIE Optics + Photonics.

[5]  Carol J. Bruegge,et al.  Use of Spectralon as a diffuse reflectance standard for in-flight calibration of earth-orbiting sensors , 1993 .

[6]  Junqiang Sun,et al.  Degradation nonuniformity in the solar diffuser bidirectional reflectance distribution function. , 2016, Applied optics.

[7]  Menghua Wang,et al.  On-orbit characterization of the VIIRS solar diffuser and solar diffuser screen. , 2015, Applied optics.

[8]  J. Butler,et al.  VIIRS on‐orbit calibration methodology and performance , 2014 .

[9]  David I. Moyer,et al.  Operational calibration of VIIRS reflective solar band sensor data records , 2012, Optics & Photonics - Optical Engineering + Applications.

[10]  Gerhard Meister,et al.  On-orbit calibration of the Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite for ocean color applications. , 2015, Applied optics.

[11]  Junqiang Sun,et al.  Visible Infrared Imaging Radiometer Suite solar diffuser calibration and its challenges using a solar diffuser stability monitor. , 2014, Applied optics.

[12]  Amit Angal,et al.  Time-Dependent Response Versus Scan Angle for MODIS Reflective Solar Bands , 2014, IEEE Transactions on Geoscience and Remote Sensing.

[13]  Xiaoxiong Xiong,et al.  On-Orbit Calibration and Performance of Aqua MODIS Reflective Solar Bands , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[14]  Junqiang Sun,et al.  Radiometric calibration of the Visible Infrared Imaging Radiometer Suite reflective solar bands with robust characterizations and hybrid calibration coefficients. , 2015, Applied optics.

[15]  J. Sun,et al.  NPP VIIRS on-orbit calibration and characterization using the moon , 2012, Optics & Photonics - Optical Engineering + Applications.

[16]  Amit Angal,et al.  MODIS reflective solar bands calibration improvements in Collection 6 , 2012, Asia-Pacific Environmental Remote Sensing.

[17]  Junqiang Sun,et al.  On-orbit calibration of Visible Infrared Imaging Radiometer Suite reflective solar bands and its challenges using a solar diffuser. , 2015, Applied optics.

[18]  Junqiang Sun,et al.  VIIRS Reflective Solar Bands Calibration Progress and Its Impact on Ocean Color Products , 2016, Remote. Sens..

[19]  Xiaoxiong Xiong,et al.  MODIS Reflective Solar Bands On-Orbit Lunar Calibration , 2007, IEEE Transactions on Geoscience and Remote Sensing.