ScanPol polarimeter optical design |
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Spectral band: 370-1610 nm, six spectral channels: 370 nm – tropospheric aerosol and top of clouds 410 nm – aerosol over ocean and surface 555 nm – aerosol over ocean and surface, ocean color 865 nm – aerosol over ocean and surface 1378 nm – separate cirrus clouds, stratosphere aerosol, separation of troposphere and stratosphere aerosol in case of volcanic eruption 1610 nm – separation surface signal from aerosol over Earth’ surface Filter ½ width 20 - 60 nm |
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Observable Stokes parameters: I, Q, U (0,90,45,135°) Photometric accuracy: 4% Polarimetric accuracy: 0.15% On-board calibration: all three Stokes parameters |
ScanPol is similar to APS Glory |
ScanPol on-board calibration units |
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Radiometric calibration unit | Unpolarized calibration unit | Polarized calibration unit |
ScanPol polarimeter laboratory test |
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Equivalent polarization scheme of the ScanPol polarimeter. |
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ScanPol standard error is 0.0008, correspondent to relative error 0.08% |
ScanPol polarimeter calibration model, 2018 |
The scan mirrors and calibration units layout of the ScanPol instrument: red segment - scan mirrors; blue element - quarts wedges of the depolarization unit; green element - the Glan prism polarizer unit, black element is the dark unit; solar calibration unit seen at βs angle. Scanning directions along-track between scan angle βm1 = +50° and βm2 = –60° from nadir (βnadir). |