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New Release: Validation Viewer Interactive Tool

Posted on Wednesday, December 10, 2025 at 12:00:00

The Validation Viewer enables users to dynamically visualize satellite - in-situ matchup pairs. In Version 1 of the tool, we focus on remote sensing reflectance, Rrs (sr⁻¹), from the PACE OCI Apparent Optical Properties (AOPs) product suite. Matchups are displayed geographically on an interactive map that allows users to explore different matchup sites worldwide. These matchups follow the standard SeaBASS matchup criteria as described in Bailey and Werdell (2006). These results in the Validation Viewer is not a replacement of the official validation results.

In addition to Rrs, the tool aggregates a comprehensive set of auxiliary parameters, including solar and sensor geometry, water depth, and key atmospheric-correction byproducts such as aerosol optical thickness (AOT) and the Ångström exponent. We also include critical matchup-quality metrics used in the selection process, such as the number of valid pixels within the 5x5 extraction region, the coefficient of variation (CV) within the matchup area, and the QWIP scores for both satellite and in-situ Rrs. These combined parameters allow users to filter, stratify, and tailor their matchup queries to specific scientific or validation needs.

For each matchup, the tool provides an individual validation panel showing the available hyperspectral Rrs. To ensure that satellite and in-situ spectra are directly comparable, all PACE Rrs data are spectrally convolved to a common grid using a 10-nm square bandpass filter, sampled at 5-nm intervals. This spectral adjustment matches the typical resolution of most in-situ radiometers (~10 nm) and ensures consistency across all matchups. Having all Rrs on a unified spectral grid also enables the generation of robust in-situ vs. PACE scatterplots, wavelength-dependent diagnostics, and summary validation statistics.