Pre-launch calibration and validation of the Airborne Hyper-Angular Rainbow Polarimeter (AirHARP) instrument

Details

• Journal Title:
  Atmospheric Measurement Techniques
• Personal Author:
  McBride, Brent A. ; Martins, J. Vanderlei ; Cieslak, J. Dominik ; Fernandez-Borda, Roberto ; Puthukkudy, Anin ; Xu, Xiaoguang ; Sienkiewicz, Noah ; Cairns, Brian ; Barbosa, Henrique M. J.
• NOAA Program & Office:
  CESSRST (Cooperative Science Center for Earth System Sciences and Remote Sensing Technologies) ; Education and outreach
• Description:
  The Airborne Hyper-Angular Rainbow Polarimeter (AirHARP) is a new imaging polarimeter instrument capable of sampling a single Earth target from up to 120 viewing angles, in four spectral channels, and in three linear polarization states across a 114° field of view (FOV). AirHARP is telecentric in the image space and simultaneously images three linear polarization states with no moving parts. These two aspects of the design allow for a simple and efficient quantitative calibration. Using coefficients derived at the center of the lens and the detector flatfields, we can calibrate the entire AirHARP sensor in a variety of laboratory, field, and space environments. We show that this telecentric calibration technique yields a 1σ absolute uncertainty of 0.25 % in degree of linear polarization (DOLP) in the laboratory for all channels and for pixels around the optical axis. To validate across the FOV, we compare our multi-angle reflectance and polarization data with the Research Scanning Polarimeter (RSP) over targets sampled during the NASA Aerosol Characterization from Polarimeter and Lidar (ACEPOL) campaign. We use the error-normalized difference technique to estimate how well the instruments compare relative to their error models. We find that AirHARP and the RSP reasonably agree for reflectance and DOLP within 2 standard deviations of their mutual uncertainty at 550, 670, and 870 nm and over a limited set of ocean and desert scenes. This calibration technique makes the Hyper-Angular Rainbow Polarimeter (HARP) design attractive for new spaceborne climate missions: HARP CubeSat (2020–2022), HARP2 (2024–) on the NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE), and beyond.
• Source:
  Atmospheric Measurement Techniques, 17(19), 5709-5729
• DOI:
  https://doi.org/10.5194/amt-17-5709-2024
• ISSN:
  1867-8548
• Format:
  PDF
• Publisher:
  Copernicus GmbH
• Document Type:
  Journal Article
• Funding:
  Grant no. NA16SEC4810008
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:da44a4d4b60941966eeb3219479fb168f3a5fb2227f853136e8b36a118454b861ea76306a3a2f0b08030e3fe602b062a052cecd8f2f26bf8a5ca1d84fabd06ff
• Download URL:
  https://repository.library.noaa.gov/view/noaa/70203/noaa_70203_DS1.pdf
• File Type:
  [PDF - 5.73 MB ]