Sense and Avoid Sensor Selection for Small UAV

Detect, sense and avoid (DSA) systems are responsible for detecting conflicting traffic, determining the right of way, analyzing flight paths, maneuvering to avoid collision, and communicating with other aircraft in the air.  The requirements for DSA for commercial Unmanned Aerial Vehicles (UAVs) are currently still in work by the Federal Aviation Administration (FAA) however an outline of what it will most likely look like is available.  UAVs under 55lbs that are flown for recreation or hobby purposes currently have no requirements for sense and avoid other than they must be flown within line-of-sight away from populated areas, however the requirements for commercial UAV usage flying beyond-line-of-sight (BLOS) will be much more rigorous (Berry, 2009). 

For detecting conflicting traffic, the UAV system will need to continuously be scanning for threats, minimize false alarms and misses, provide an operator threat data, cover a field of view of 110 degrees horizontal and +/- 15 degrees azimuth, track all targets within a minimum range, and determine closure rates (Berry, 2009).  The system will need to be able to detect and identify potential collisions at a far enough range that a minimum of 500ft separation between vehicles can be maintained (Berry, 2009).  It will do so by making use of the sensors on-board to calculate flight paths and determine the time available before needing to maneuver to avoid a potential collision (Berry, 2009).  For a small UAV of less than 55lbs the microPOP electro-optical stabilized payload is a great option for helping achieve this.

The microPOP is a great option because it allows for both day and night usage making use of a color zoom camera with near infrared (IR) capabilities for daytime operations and an uncooled forward looking infrared (FLIR) camera for night operations (MicroPOP, 2015).  The day and night payloads can be interchanged quickly and depending on configuration have a system weight of between 2.2 and 3 lbs (MicroPOP, 2015).  At a cost of over $100,000 for each unit it is not a cheap option by any stretch but the capabilities it offers far surpass just strapping a HD camera onto your aircraft (MicroPOP, 2015).  Available options to add on in addition to the camera include a laser range finder, laser pointer, automatic video tracker, HDTV, and INS/GPS (MicroPOP, 2015).  The sensor is compact at only 4” in diameter and 7” tall, while requiring a 23 Watts of power in order to run (MicroPOP, 2015).  The field of view is 170 degrees horizontal and -90 degrees, + 20 degrees azimuth with a slewing rate of 100 degrees/sec on the gimbal (MicroPOP, 2015).  The day camera also features 10x continuous zoom.  The microPOP sensor is currently being used successfully on UAV’s such as the Panther Fixed Wing VTOL UAS and the BirdEye 400 UAV.  For small unmanned systems on short-range observation missions it is an excellent option for providing enhanced imaging capabilities to assist in a sense and avoid system.

References

Berry, M., Hansen, K.R., Hottman, S. B. (2009). Literature Review on Detect, Sense, and Avoid Technology for Unmanned Aircraft Systems

(DOT/FAA/AR-08/41). Las Cruces: FAA.

MicroPOP Electro-Optical Stabilized Payload. (2015). Retrieved from http://www.iai.co.il/2013/18688-34442-en/SystemMissileandSpace_Tamam_Electro-Optical.aspx