How a NASA Sensor the Size of a Toaster Oven Could Help Predict ‘Fire Weather’

07/22/26 — Wildfires can generate their own weather, triggering self-sustaining wind patterns and even spewing enough soot and particulate matter into the atmosphere to create their own lightning, precipitation, and even tornadoes. Forecasting this ‘fire weather’ is a unique challenge for first responders and wildfire managers.

The Pyro-atmosphere Infrared Sounder (PIRS), developed by researchers at NASA’s Jet Propulsion Laboratory (JPL) with help from the agency’s Earth Science Technology Office (ESTO), aims to address that challenge. This instrument will leverage a cutting-edge optics assembly to measure features like heat, moisture, and carbon monoxide in three dimensions, equipping wildfire managers with information they can use to not only combat active blazes, but also to better understand the complex relationship between wildfires and weather.

Sun Wong, a Research Scientist at JPL and Principal Investigator for PIRS, explained that their instrument will be able to generate thermal images of a wildfire at a spatial resolution of 30 meters per pixel from an altitude of about five miles (8.5 kilometers), an unprecedented feat for a compact sensor.

PIRS passed rigorous ground testing in November 2025. Now, the research team is preparing PIRS to fly aboard NASA’s Beechcraft King Air B200 in a technology demonstration over actual wildfires during an upcoming field campaign in Boise, Idaho, in Summer 2026.

“This instrument is significantly smaller than previous infrared sounders. It’s going from an instrument the size of a refrigerator to a toaster oven,” said Alex Soibel, an electrical engineer at JPL and co-investigator for PIRS.

Several technological innovations allow PIRS to observe a wide variety of atmospheric constituents while remaining small. The instrument uses an infrared detector called High Operating Temperature Barrier Infrared Detector (HOT-BIRD) that operates reliably at warmer temperatures than traditional infrared sensors, allowing PIRS to fly with smaller cryocoolers than traditional sensors require.

PIRS features a state-of-the-art spectrometer that relies on a novel refractive optics assembly to channel infrared signals from the instrument’s aperture to HOT-BIRD. This state-of-the-art assembly reduces the overall size of the instrument and allows it to achieve better image quality across a wide field of view.

“The spectrometer is small. You can hold it in your hand. It’s this teeny, little thing,” said Thomas Pagano, an instrument systems engineer at JPL and lead engineer for PIRS.

Finally, the instrument features a novel immersion grating spectrometer capable of splitting light into 640 unique spectral channels across the mid-infrared spectrum between 4.08 and 5.13μm. By observing slices of the atmosphere at different wavelengths (a technique known as ‘sounding’), PIRS collects the data scientists need to construct three-dimensional models showing temperature, moisture, and carbon monoxide.

That capability could have applications beyond Earth. Researchers who study Mars are considering using PIRS to help study the Martian atmosphere, providing key insights into Martian weather and potential landing sites for a future crewed mission.

“Planetary scientists need an instrument that can probe the condition of the Martian atmosphere to select potential landing sites and predict storms correctly. PIRS could be useful for that,” said Soibel.

But for now, the researchers developing PIRS are focused on using NASA technology innovations to help people on Earth study and manage wildfires more effectively.

“One of the biggest challenges that firefighters have is predicting how the fire will develop and propagate, how fast it’s going to move and in what direction. Those are things we hope our instrument will be able to help with,” said Soibel.

ESTO’s FireSense Technology (FireTech) program funds this project. As a key element of NASA’s FireSense program, FireTech bridges the gap between technology producers and end users, validating new tools for wildfire management through comprehensive field campaigns and working closely with wildfire managers to make sure these tools suit their needs.

---

Gage Taylor, NASA Earth Science Technology Office