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:
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.