Window correction for absolute calibration factor#322
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Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Updated the default power_method from 'box' to 'adjusted_box' in the focus configuration. The adjusted_box method accounts for the effects of apodization windows in range and azimuth, giving results more comparable with methods that integrate sidelobes (e.g., ESA). Also added 'adjusted_box' to the allowed values in the schema. Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
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This PR fixes #230 by adding support for adjusting absolute calibration (abscal) measurements to account for the radiometric effects of apodization windows applied during SAR focusing.
When measuring corner reflector radar cross-section (RCS) for absolute calibration, the standard "box" method estimates power by measuring peak power and 3dB widths. However, this approach doesn't account for power loss due to windowing (apodization) in range and azimuth processing. This PR implements a correction factor that adjusts measured RCS values to be more comparable with methods that integrate sidelobes (e.g., ESA's approach).
The change is about 0.5 dB for NISAR. The correction can be enabled by selecting "adjusted_box" in the runconfig or CLI (cc @nemo794 since QA does its own schema validation).