Two NASA-developed technologies are key components of a new high-resolution sensor for observing wildfires: High Operating Temperature Barrier Infrared Detector (HOT-BIRD), developed with support from NASA’s Earth Science Technology Office (ESTO), and a cutting-edge Digital Readout Integrated Circuit (DROIC), developed with funding from NASA’s Small Business Innovation Research (SBIR) program.

A novel space-based sensor for observing wildfires could allow first responders to monitor burns at a global scale, paving the way for future small satellite (SmallSat) constellations dedicated entirely to fire management and prevention.

Developed with support from NASA’s Earth Science Technology Office (ESTO), the “Compact Fire Infrared Radiance Spectral Tracker” (c-FIRST) is a small, mid-wave infrared sensor that collects thermal radiation data across five spectral bands. Most traditional space-based sensors dedicated to observing fires have long revisit times, observing a scene just once over days or even weeks. The compact c-FIRST sensor could be employed in a SmallSat constellation that could observe a scene multiple times a day, providing first responders data with high spatial resolution in under an hour.

In addition, c-FIRST’s dynamic spectral range covers the entire temperature profile of terrestrial wild fires, making it easier for first-responders to detect everything from smoldering, low-intensity fires to flaming, high intensity fires.

“Wildfires are becoming more frequent, and not only in California. It’s a worldwide problem, and it generates tons of by-products that create very unhealthy conditions for humans,” said Sarath Gunapala, who is an Engineering Fellow at NASA’s Jet Propulsion Laboratory (JPL) and serves as Principal Investigator for c-FIRST.

The need for space-based assets dedicated to wildfire management is severe. During the Palisade and Eaton Fires earlier this year, strong winds kept critical observation aircraft from taking to the skies, making it difficult for firefighters to monitor and track massive burns.

Space-based sensors with high revisit rates and high spatial resolution would give firefighters and first responders a constant source of eye-in-the-sky data.

“Ground-based assets don’t have far-away vision. They can only see a local area. And airborne assets, they can’t fly all the time. A small constellation of CubeSats could give you that constant coverage,” said Gunapala.

c-FIRST leverages decades of sensor development at JPL to achieve its compact size and high performance. In particular, the quarter-sized High Operating Temperature Barrier Infrared Detector (HOT-BIRD), a compact infrared detector also developed at JPL with ESTO support, keeps c-FIRST small, eliminating the need for bulky cryocooler subsystems that add mass to traditional infrared sensors.

With HOT-BIRD alone, c-FIRST could gather high-resolution images and quantitative retrievals of targets between 300°K (about 80°F) to 1000°K (about 1300°F). But when paired with a state-of-the-art Digital Readout Integrated Circuit (DROIC), c-FIRST can observe targets greater than 1600°K (about 2400°F).

Developed by Copious Imaging LLC. and JPL with funding from NASA’s Small Business Innovation Research (SBIR) program, this DROIC features an in-pixel digital counter to reduce saturation, allowing c-FIRST to capture reliable infrared data across a broader spectral range.

Artifical intelligence (AI) will also play a role in c-FIRST’s success. Gunapala plans to leverage AI in an onboard smart controller that parses collected data for evidence of hot spots or active burns. This data will be prioritized for downlinking, keeping first responders one step ahead of potential wildfires.

“We wanted it to be simple, small, low cost, low power, low weight, and low volume, so that it’s ideal for a small satellite constellation,” said Gunapala.

Gunapala and his team had a unique opportunity to test c-FIRST after the Palisade and Eaton Fires in California. Flying their instrument aboard NASA’s B-200 Super King Air, the scientists identified lingering hot spots in the Palisades and Eaton Canyon area five days after the initial burn had been contained.

Now, the team is eyeing a path to low Earth orbit. Gunapala explained that their current prototype employs a standard desktop computer that isn’t suited for the rigors of space, and they’re working to incorporate a radiation-tolerant computer into their instrument design.

But this successful test over Los Angeles demonstrates c-FIRST is fit for fire detection and science applications. As wildfires become increasingly common and more destructive, Gunapala hopes that this tool will help first responders combat nascent wildfires before they become catastrophes.

“To fight these things, you need to detect them when they’re very small,” said Gunapala.

A publication about c-FIRST appeared in the journal “Society of Photo-Optical Instrumentation Engineers” (SPIE) in March, 2023.

For additional details, see the entry for this project on NASA TechPort.

To learn more about emerging technologies for Earth science, visit ESTO’s open solicitations page.

 Sarath Gunapala, NASA Jet Propulsion Laboratory (JPL)

NASA ESTO