AI Insight
Researchers developed a method to detect wildfire temperatures at sub-pixel resolution using imaging spectroscopy from NASA's AVIRIS-3 instrument. The framework uses a full-physics approach with forward modeling to separate solar and thermal radiation across the full spectral range, achieving temperature estimates with root mean square errors of 41.8 Kelvin in simulations and mean absolute errors of 27.16 Kelvin when applied to 168 wildfire overflights during the 2025 FireSense campaign. The method successfully translates to space-borne sensors like EMIT, maintaining accuracy even at coarser spatial resolutions.
Why it matters
This technique enables real-time monitoring of wildfire temperatures from satellites, which could improve fire behavior prediction, resource allocation for firefighting efforts, and damage assessment. The ability to detect sub-pixel temperature variations means fires can be characterized more precisely even when they occupy only small portions of a satellite image pixel.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Abstract: In this work, we present a wildfire temperature retrieval framework for VSWIR imaging spectroscopy data, employed on data from NASA’s Airborne Visible Infrared Imaging Spectrometer (AVIRIS-3). The retrieval framework utilizes a full-physics approach in which a forward model is employed to resolve both solar and emitted radiance derived from a temperature distribution and utilizes the full spectral range in the residual fit. To optimize the forward model retrieval, we use state-of-the-art nonlinear least squares methods implemented for fast convergence on the on-board GPU, allowing for estimation of effective fire temperature within flight cadence. We verify the forward model assumptions on simulated spectra with an injected thermal signature and find good agreement with an RMSE of $41.8$ Kelvin (K). We apply the retrieval over the full 2025 FireSense AVIRIS-3 campaign, totaling 168 overflights with probable active fire spectra, and demonstrate a residual radiance fit of $leq 10%$ across bands in the short-wave infrared (SWIR). Lastly, we verify the applicability of the retrieved posterior fire temperature parameters to generalize to space-borne imaging spectrometers such as EMIT, by retrieving at coarsened spatial resolution. We find that the posterior distribution exhibits good coverage of the underlying sub-pixel temperature range with an absolute error of $30$ K across quantiles and a mean absolute error of $27.16$ K between spatial resolutions.