Using Tactical Unmanned Aerial Systems to Monitor and Map Wildfires

Transcription

1 Using Tactical Unmanned Aerial Systems to Monitor and Map Wildfires Michael Tranchitella, Stephen Fujikawa, Tzer Leei Ng, David Yoel, Don Tatum IntelliTech Microsystems, Inc. Bowie, Maryland Philippe Roy, Christophe Mazel Mercury Computer Systems 199 Riverneck Road Chelmsford, MA Dr. Stanley Herwitz UAV Collaborative NASA Research Park Mail Stop 18-2 Moffett Field, CA Everett Hinkley USDA Forest Service Remote Sensing Applications Center Salt Lake City, Utah Introduction In June of 2006, the author s Vector P Unmanned Aerial System (UAS) was invited to participate in a demonstration of small UASs sponsored by the US Forest Service in partnership with NASA-Ames Research Center. The focus of the demo was to identify and test the usefulness of unmanned tactical aircraft in the monitoring and mapping of wildfires. The intention is to use unmanned systems to provide persistent surveillance when conditions are unsafe or impractical for manned flight particularly at night. This paper details the Vector P UAS, its avionics package, payload, ground control station, operational procedures and its ability to fly day and night through smoke and wind. Also described is new emerging sense and avoid technology that provides airspace deconfliction for unmanned aircraft in operational areas populated by manned aircraft.

2 The Vector P Originally conceived in 2001, the Vector P was designed as a pathfinder vehicle for IntelliTech s entry into the unmanned aircraft arena. Six years later the aircraft has matured into an excellent aerial platform. The airframe features 101 wingspan and all composite construction. A generous payload bay and a three gallon fuel tank make it an extremely versatile system. A 75cc gas two-stroke engine provides excellent power at its maximum take off weight of 75 pounds and an economical fuel consumption rate of just.5 gallons per hour. Endurance times can range from 30 minutes to six hours depending on the payload and mission parameters. The Avionics Section The Vector utilizes a commercially available GPS guided autopilot and IntelliTech developed control circuitry. Featuring a 900 MHz Spread Spectrum Data-link and 2.4 GHz Spread Spectrum manual piloting link, the Vector is able to perform in some of the harshest RF environments. For safety, we have added redundant servos, short protection and a back up 900 MHz manual pilot link.

3 Wildfire Payload For this demo, Vector P was equipped with a camera package consisting of both color (EO) and infrared (IR) cameras on gimbaled mounts. The EO/IR data were downlinked to the ground station via a 2.4 GHz link, where they were viewed on projection TV by the attendees present. Vector with gimbaled cameras Ground Control Station (GCS) The GCS maintains a small footprint by utilizing a standard laptop computer to handle mission parameters and to monitor flight progress. A 900 MHz hand held or base mounted modem is used for downlink telemetry and uplink commands. Power is supplied via a 120 volt source or 12 volt DC battery and 500 watt power inverter. Partnering with IntelliTech, Mercury Computer Systems unveiled their new VistaNav ground station software which features multiple flight screens and 3D graphics. This new software keeps the pilot on top of the mission and flight progression. Vector GCs and Mercury Computer Systems VistaNav Software

4 Operational Procedures A typical Vector P mission begins with a briefing of the flight crew and mission commander to determine the flight plan and mission goals. Safety is always priority and all potential trouble areas are addressed. Following the Vector preflight check list the aircraft is then readied for flight and taxied onto the runway for take-off. Depending on the environment, take-off and flight clearances are obtained and the aircraft is manually piloted to the hand-off point where the autopilot assumes control. At Fort Hunter, the plane was manually piloted to 1500 feet (AGL) and control was passed to the autopilot. It then initiated a climb to 5000 feet (AGL) as it navigated to the targeted fire area. Upon reaching the suspected fire area the Vector P entered an observation orbit where the payload operator searched for the fire using the video feed. In an operational environment this information would allow firefighters with PDA s greater situational awareness of the fire area. Once the loiter fuel was used the autopilot was commanded to complete the flight plan which involved the aircraft flying back to the runway and entering a descending orbit. At an altitude of 400 feet manual control of the aircraft was assumed and the plane configured for landing. This was commenced on Fort Hunter s 600 runway where the Vector P used 500 feet from touchdown to full stop.

5 Flight Path of Vector P at Ft. Hunter Liggett. Takeoff and climb out from airport at lower left of center. Orbiting over ridge fire line at upper right of center. Day and Night through Smoke and Wind During the wildfire demonstration the Vector P made three daytime flights and one night flight with durations of 45 to 60 minutes. Winds during this time ranged from 2 to 15 mph including some crosswinds. In testing and demonstration flights the Vector has handled headwinds to 30 mph and crosswinds to 20 mph. Over the fire area where updrafts can be present the Vector maintained its flight plan and altitude with great precision, holding altitude within 25 feet, airspeed within 10 mph and orbit point within 30 feet. Smoke from the controlled burns was present and had no effect on the IR camera or flight operation of the Vector P. Controlled burns Vector monitored

6 Night flying with the Vector P is aided by utilizing ultra bright LED navigation and anti-collision strobe lights. The lightweight system is easily viewed by the manual pilot up 1000 feet away. The orientation and color of the lights allows the manual pilot to determine the aircraft s attitude while airspeed and altitude information is relayed via intercom from the GCS operator. The lights are configured as advised by the FAA for light aircraft and were seen from 5 miles. Vector with navigation lights Sense and Avoid One of the latest hot topics is the Federal Aviation Administration s (FAA) regulation of UAS flight in national airspace. The biggest safety concern is the inability for UASs to see or be seen by manned aircraft. NASA has developed a radar system called SAVDS that uses the downlink telemetry from the UAS as well as radar to identify the UAS and its position. At the same time it plots any manned aircraft positions allowing controllers and pilots to make course corrections in order to avoid a collision. This revolutionary technology would be a great benefit to many UAS applications, especially the USFS and firefighting where multiple aircraft platforms are utilized. This technology was used to track the Vector s progress through Fort Hunter s restricted airspace. In post Fort Hunter demonstration flights held at NASA s San Bernabe, California facility, the SAVDS system was used to initiate a collision avoidance maneuver where the Vector P avoided an intruding manned aircraft.

7 Summary From the first takeoff to the final night landing it was apparent that small tactical unmanned aerial systems have their place in the wildfire environment. The Vector P UAS demonstrated persistent surveillance and gathered information when it was unsafe or impractical to use manned aircraft. Firefighters in the fire area commented that the system was a welcome sight overhead knowing that critical information was being broadcast and monitored.