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MODIS has 36 spectral bands with wavelengths in the visible (VIS), near-infrared (NIR), short-wave infrared (SWIR),
mid-wave infrared (MWIR), and long-wave infrared (LWIR). It makes observations at three nadir spatial resolutions:
0.25km for bands 1-2 (40 detectors per band), 0.5km for bands 3-7 (20 detectors per band), and 1km for bands 8-36 (10
detectors per band). The VIS, NIR, and SWIR are the reflective solar bands (RSB), which are calibrated on-orbit by a
solar diffuser (SD) and a solar diffuser stability monitor (SDSM). The bi-directional reflectance factor (BRF) of the SD
provides a RSB calibration reference and its on-orbit changes are tracked by the SDSM. In addition, MODIS lunar
observations are regularly scheduled and used to track the RSB calibration stability. On-orbit observations show that the
changes in detector response are wavelength and scan angle dependent. In this study, we focus on detector-to-detector
calibration differences in the MODIS VIS/NIR spectral bands, which are determined using SD and lunar observations,
while the calibration performance is evaluated using the Earth view (EV) level 1B (L1B) data products. For Aqua
MODIS, the detector calibration differences and their impact are also characterized using standard ocean color data
products. The current calibration approach for MODIS RSB carries a band-averaged response versus scan angle (RVS)
correction. The results from this study suggest that a detector-based RVS correction should, due to changes in the scan
mirror's optical properties, be implemented in order to maintain and improve the current RSB L1B data product quality,
particularly, for several VIS bands in Terra MODIS.
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