Validation of AirHARP calibration with coincident observations by SPEX Airborne, AirMSPI, and RSP polarimeters during the ACEPOL field campaign
Abstract
The Airborne Hyper-Angular Rainbow Polarimeter (AirHARP), designed and developed by the Laboratory for Aerosol and Cloud Optics (LACO) at the University of Maryland, Baltimore County (UMBC) is a wide field-of-view (FOV), hyper-angular imaging polarimeter for the microphysical sampling of clouds and aerosols from aircraft and space. This instrument performs comprehensive atmospheric measurements in both total radiance and polarization, at 4 VNIR wavelengths and up to 60 unique viewing angles per wavelength, in a compact, low-cost, and easily scalable CubeSat payload. AirHARP is the airborne demonstration of the upcoming HARP CubeSat standalone instrument (2018, ISS orbit) and the HARP-2 polarimeter on the Plankton-Aerosol-Cloud-ocean Ecosystem (PACE) satellite (2021, sun-synchronous polar orbit).
AirHARP was characterized and calibrated in a laboratory setting, and to validate its radiometric/polarimetric calibration accuracy in the field, we intercompared coincident total reflectance and degree of linear polarization data from the SPEX Airborne, the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI), and the Research Scanning Polarimeter (RSP) during the Aerosol Characterization by Polarimeter and LIDAR (ACEPOL) field campaign. Specifically, the AirHARP wide FOV and hyper-angular capability complements and extends the hyper-spectral sampling and narrow swath of SPEX Airborne. This intercomparison supports current discussion on cross-calibration and joint retrieval capability of their HARP-2 and SPEXone iterations on the upcoming PACE mission. The four polarimeters observed highly polarized sunglint (DOLP 1), Rayleigh scattering, open ocean, vicarious calibration sites, marine stratocumulus, and land scenes in total and linear polarized radiances. The range of values present in these natural environments are sufficient to cross-characterize AirHARP calibration accuracy for any potential observation. We will also compare the AirHARP uncertainty model to observations during ACEPOL and discuss how AirHARP field measurements compare to the expected performance of the upcoming HARP CubeSat and HARP-2 instruments.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A13A..03M
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0394 Instruments and techniques;
- ATMOSPHERIC COMPOSITION AND STRUCTURE