Please join us for this GHRSST Talk with David Wethey on:

ECOSTRESS Calibration and Bias Correction by In-Orbit Comparison with CrIS and IASI

Authors

  1. David S. Wethey, University of South Carolina, Columbia SC 29208, USA, dswethey@gmail.com
  2. Sarah A. Woodin, University of South Carolina, Columbia SC 29208, USA
  3. Jorge Vazquez Cuervo, Jet Propulsion Laboratory, Pasadena CA 91109, USA

Abstract

ECOSTRESS is a push-whisk instrument with 5 infrared bands centered on 8.28, 8.78, 9.20, 10.49, and 12.09 µm.  Radiance calibration on orbit is achieved with two onboard black bodies at temperatures of 293 K and 319K that are imaged on each mirror rotation.  ECOSTRESS Collection 1 data has ~1 K temperature bias relative to in-situ land and ocean observations and VIIRS retrievals. The bias was partially corrected with linear gain and offset coefficients applied to the channel radiances in ECOSTRESS Collection 2, but biases still exist in Collection 2, among individual detectors along the focal plane array.

Hyperspectral data from collocated Crosstrack Infrared Sounder (CrIS) and Infrared Atmospheric Sounding Interferometer (IASI) observations were used to improve on-orbit calibration of individual pixels in the ECOSTRESS focal plane array. Sounder spectra were convolved with the spectral responses of ECOSTRESS channels and compared to retrieved radiances of pixels within the Sounder fields of view (FOV). We used only homogeneous FOVs where the standard deviation among ECOSTRESS brightness temperatures (BT) was less than 0.3 K. The negative parabolic distribution of 10.49 µm BT bias along the focal plane is consistent with the pattern of retrieved temperature bias. Correction of the 10.49 µm BT bias pattern should reduce striping and checkerboard artifacts in ECOSTRESS SST, supporting our plan to produce a split-window GHRSST compatible SST for archiving at PODAAC.

About David

David is a member of the ECOSTRESS Science Team and the GHRSST Task Team on Climatology and L4 Inter-Comparison. David’s current NASA projects are 1) High Resolution Sea Surface Temperature from ECOSTRESS (J Vazquez Cuervo, CoPI), and 2) ECOSTRESS – Heat and Desiccation Risk Prediction in Intertidal Shellfisheries (S A Woodin and T J Hilbish, CoPIs). David is a Professor Emeritus of Biological Sciences at the University of South Carolina.

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