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Please open in “Notes” mode to see the notes. SAM (Sun and Aureole Measurement) Calibration. Prepared for MODIS/VIIRS Science Team Meeting Dennis Villanucci, Andrew LePage John DeVore, A.T. Stair January 2010. 1. Introduction. SAM radiance measurements Solar disk and aureole profiles
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Please open in “Notes” mode to see the notes. SAM (Sun and Aureole Measurement) Calibration Prepared for MODIS/VIIRS Science Team Meeting Dennis Villanucci, Andrew LePage John DeVore, A.T. Stair January 2010
1. Introduction • SAM radiance measurements • Solar disk and aureole profiles • At 670 +/- 5 nm • Lab calibration NIST traceable • Field verification using AERONET for low ODs • Radiometric accuracy: • Disk radiance <1%, if OD<~0.6 • Disk radiance <~10%, otherwise • Aureole radiance ~15% • Aureole profile precision (gradient): • Pixel-to-Pixel Stnd Dev <0.5%
3. SAM/AERONET Radiance Statistics • RMS difference < 0.7% (~1000 values)
7. Typical Uniform Cloud Data Traces • Demonstrates precision of profile
8. Radial Average, Std Dev of Traces • Demonstrates precision of profile
9. Non-uniform Cloud Example • Cloud non-unformity is detectable
10. Moderately Thick Cloud Example • Demonstrates accuracy (2 cameras) and precision of profile (gradient)
11. Field Calibration Verification • For absolute radiometric calibration of cameras; verified for solar disk radiance with thousands of measurements next to AERONET sensors • For flat fielding of aureole pixel-to-pixel response, e.g. “gradient” correction; verified with hundreds of measurements of uniform clouds
SAM Applications • Climate (cloud) monitoring • Cloud physics research • Satellite algorithm cal/val • Circumsolar radiation Contacts: Dennis Villanucci 781-272-1220 villa@visidyne.com Andrew LePage 781-272-1220 lepage@visidyne.com