Forest Service receives new airborne sensor from NASA

USFS IR aircraft, Cessna Citation Bravo
USFS IR aircraft, Cessna Citation Bravo
One of the U.S. Forest Service’s Infrared aircraft, their Cessna Citation Bravo, N144Z

The U.S. Forest Service has been using dedicated fixed wing aircraft with infrared sensors to detect and map wildland fires since the 1960s or 1970s. So I was intrigued after reading a news release from NASA about an airborne sensor that will help gather information about wildland fires. Here is an excerpt:

NASA Imaging Sensor Prepares for Western Wildfire Season

WASHINGTON – Airborne imaging technology developed at NASA and transferred to the U.S. Department of Agriculture’s Forest Service (USFS) in 2012 is being tested to prepare for this year’s wildfire season in the western United States.
The Autonomous Modular Sensor (AMS) is a scanning spectrometer designed to help detect hot-spots, active fires, and smoldering and post-fire conditions. Scientists at NASA’s Ames Research Center in Moffett Field, Calif., and USFS engineers installed it on a Cessna Citation aircraft that belongs to the Forest Service. The USFS plans to use it in operational fire imaging and measurement…

Having experience as an Infrared Interpreter (IRIN), converting data on infrared images to maps so that the information can be used by firefighters on the ground, I wanted more information about how this sensor will be used in wildfire management. I knew that the person with the answers would be Woody Smith, an Avionics and Infrared Technician with the U.S. Forest Service’s National Infrared Operations (NIROPs) unit. I sent him some questions by email and here is his response:


(Woody said:)

The main purpose for the transfer of the AMS Sensor to the USFS is for additional remote sensing needs. Missions such as forest health sensing, post fire analysis, and earth mapping. The AMS has the capability to map wildfires and will be used as an additional system in a third aircraft if one becomes available.

But to answer your questions in order:

Is this replacing previous sensor(s)?

No. This will be an additional system to enhance our capabilities for busy seasons. Though for now, it “lives” on the Citation (N144Z) for testing and comparison purposes. Once the NIROPs Unit begins to get busy we will remove this system and reinstall the Phoenix System. We anticipate using the AMS sensor during the “off season” for earth observation and post fire analysis.

What is the advantage of this sensor?

The AMS Sensor has 16 channels that can be used to map the earth simultaneously. Most of the channels are in the visual range and color IR. There are 4 used for thermal IR (TIR) and as soon as I get permission from the guys at NASA I will send you a briefing paper that explains the origin and uses of the AMS. For now, the USFS intends to map some vegetation areas for various other government agencies and fly real time comparison flights over wild land fires. We need to assess its operational capabilities. One advantage is the capability to perform scientific earth observation for post fire analysis while collecting and mapping wild land fires.

On the new AMS system, is liquid nitrogen still used to cool the sensor, like on the Phoenix System currently being used?

No. The TIR (thermal infrared) channels use sterling coolers and thermo electric (TE) coolers. But as the Phoenix System will hold LN2 for over 16 hours we only have to fill them once a day before the night’s flights begin. (Sterling coolers and thermo-electric cooling is very expensive while liquid nitrogen is very cheap!)

How many sensors does the USFS IR system use?

We currently own 6 ea 2-channel thermal IR scanner systems. 2 from Daedalus and 4 that we developed ourselves known as the Phoenix Wild Land Fire Mapping Systems. We could field 3 Phoenix Systems simultaneously but we only have 2 aircraft capable of carrying IR equipment so we use the additional hardware as spares for “quick repairs” during the fire season.

Will similar AMS sensors be installed on other IR aircraft?


Are there any major changes to the Infrared program for this year?

Two exciting changes coming have not yet been implemented. The first is improved heat detection and the second is with the quality of the image itself. The signal processing changes we made last year has already vastly improved the heat detection and image quality as well as sped up the delivery time. But due to a busy year (2012) we are lagging behind our anticipated schedule. As soon as these are implemented I will send you an email.


Here is a link to a Word document with a (very) technical description of the AMS sensor.

AMS-Wildfire scanhead

Typos, let us know HERE, and specify which article. Please read the commenting rules before you post a comment.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

One thought on “Forest Service receives new airborne sensor from NASA”

  1. Dear Bill,
    For the first time I went on-line to learn something about IR equipped airplanes for the Forest Service. I just read your article dated April 12, 2013 in which you discussed with Woody Smith some new equipment.
    For my own enlightenment purposes, I have just begun to study methods used by the FS out West for gathering information on fires so they can combat them with more efficiency. I have a remote mountain cabin in the headwaters area of the Salmon River of Idaho, and wild fire is a constant concern in the dry summer months.
    Recently, while the Beaver Creek fire was burning around Ketchum, Idaho, I watched three small airplanes flying over the fire in the evening hours. I presumed they were gathering information. They left, and within an hour several large tanker planes flew over. While I didn’t see them dropping retardant, I assumed that is what they were doing just west of town over the fire.
    The question I have about the information gathering IF planes is this. How soon after a fire ignites are they able to detect it? If they arrived on the scene immediately after a lightning strike would the IF equipment detect it? Also, how large an area are they able to observe in one fly over? I realize they must have line-of-sight vision, without montains in the way, so in order to ‘see’ a large area, I am guessing they must have to do a lot of flying. I can also appreciate that a limited FS budget would limit the amount of flying they can do.
    These questions came to mind recently when I read in the headlines that such and such a fire was not ‘discovered’ until it had already grown to a significent size. Most of what I read is While it’s great to have this online service, I wish they were able to update fire information more often, especially for fires that are near my own home in the Sawtooths of Idaho. I built it myself, and there is a small website showing some pictures if you are interested.
    Thanks for your helpful and valuable information on Wildland Fires. I look forward to reading all you’ve written on the subject.
    Marc Scott


Comments are closed.