Wildfire Airborne Sensor Program (WASP)
WASP's mission is the detection and monitoring of wildfires from an aircraft at an altitude of up to 12,000 feet. WASP is currently flown from a twin-engine Piper Navajo aircraft and previously used a Piper Aztec. WASP is adaptable for other Infrared or visible remote sensing applications as well. It consists of three infrared cameras and one visible camera, and can geo-reference and generate data products and then send them down to the ground station while the aircraft is still flying over the target area.
WASP has three Indigo Phoenix infrared imagers and one Geospatial Systems KCM-11 high-resolution visible camera mounted in the sensor head that looks down through a hole in the aircraft. It also has positioning devices to determine the exact position and orientation of the imagers and aircraft when each image is captured.
The IR imagers cover three bands in the infrared; short-, mid- and long-wave. They acquire 640x512 14 bit images. The KCM-11 acquires 11-megapixel color images over roughly the same space on the ground.
The four images to the left illustrate the range of the four imaging instruments in WASP. The top left image shows what this same terrain looks like in the visible spectrum. As you can see, the smoke completely obscures what's really going on, making a fire like this one potentially difficult and dangerous to fight.
The other three images show the same scene in the three infrared bands. As you can see, the heat generated by the fire is much more obvious and distinct at these wavelengths. Since these images are georeferenced, we know exactly where that fire perimeter is in latitude and longitude. Also, since infrared imaging does not depend on sunlight, we can get the same image products at any time of day or night.
Speed and Resolution
The entire assembly can acquire one frame every 4 seconds. This combined with the pivoting of the aircraft means that we can get high resolution imagery of an entire city in roughly 20 minutes in two passes with the aircraft.
The image data acquired is also passed through a georectification process in real time, which allows us to produce tiled imagery like you can see in the image to the left. This was the result of two legs in one flight we did over Rochester, NY.
All four cameras are also aligned and correlated together so that the 6 bands of image data acquired (3 IR, Red, Green, Blue) can be processed together. This means that certain features and behaviors of ground-based events can be detected.
The images are associated to each other using positioning measurements taken from IMU and GPS sensors processed by an Applanix position and orientation system. Geo-rectification software uses this data, along with a DEM of the local terrain, to correlate the imagery to precise locations on the ground.
This imagery and data can also be sent down to a base station where immediate science can be done. This also allows for ground teams to apply this information into their processes.
The ground station uses a high-gain directional antenna to transmit image and control data to and from the WASP computer, using the aircraft's GPS position to position the ground antenna. A virtual private network allows an operator anywhere on the Internet to view images in real time as well as monitor and control all of WASP's systems.
Our portable base station trailer contains communications equipment, data processing computers, space for scientists and operators to work, and all of the maintenance hardware and tools needed for remote flights. It has both battery and generator power, and can operate in remote locations.
The base station provides multiple computers for the distributed processing of the data, for operators to control the system, or for analysts to use the data products.
WASP leverages high performance PC technology for its onboard processing engine called the Airborne Data Processor, or "ADP".
The ADP is a distributed collection of software modules which include image acquisition, image processing, geo-rectification, and data logging. It also consists of a GUI application which allows the in-flight operator, as well as an operator at the base station to observe the output from the system, and control system operations.
We have made available two movies that show this application in action. These show what it would look like if you were to receive image data from the aircraft during a flight.
- [Visible imagery, geo-rectified] 66MiB Quicktime Movie
imagery, geo-rectified and false-colored] 41MiB Quicktime Movie.
(red=short, green=mid, blue=long wave ir)
There is also a second application which is run at the base station, which shows the aircraft's current location, basic system health, and geo-located image coverage. It also draws a line on provided map image data showing the path of the aircraft.
All elements of our ADP system are designed such that you can reproduce and re-run any part of any flight later with the use of simulators. This allows us to try out new software modules and algorithms as if they were running in the aircraft. This allows us for a huge amount of flexibility in that we can re-run and provide data in a simulated "live" capacity for students to test algorithms or just to try out new software procedures without needing the expensive flight times.
Science and Data Products
WASP was designed to detect fires of various sizes from a flight over the target area. The above images show three charcoal pits that were set up for a test flight.
The result image to the right show the infrared imagery taken of this scene from 5000 ft. The spots in red show where the fire detection algorithm detected fires. Three of the red spots in the center of the image are the above charcoal targets.
WASP can be used for many other scientific applications as well. It can detect warm people in cold water, along with wake shadows or thermal scars of passing boats in bodies of water, as they stir up colder or warmer water underneath them. WASP can be used for locating almost any thermal based event.
The image data acquired is geo-located, so we can also apply or overlay data from other sources to it using standard tools. By simply applying standard GIS street data to it, we can see how we can use our data products to assist with disasters and other events.