ScanPol polarimeter optical design

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

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

Radiometric calibration unit Unpolarized calibration unit Polarized calibration unit

ScanPol polarimeter laboratory test


Equivalent polarization scheme of the ScanPol polarimeter.


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).