UAS Beyond Line of Sight Operations

The PrecisionHawk is a UAS that operates beyond line-of-sight. The PrecisionHawk’s mission is to serve in diverse markets such as agriculture and information. The UAS can contribute largely to improved business through data processing and remote sensing. Beyond line-of-sight (BLOS) operations refer to operating the RPA via satellite communications or using a relay vehicle, usually another aircraft (Barnhart, Shappee, & Marshall, 2012). Typically UASs conduct missions within line of sight and do not have the ability to operate BLOS.

Photo: Redherring.com

Line-of-sight (LOS) operations allow instruction of the RPA via direct radio waves. One disadvantage is ISM frequency bands widely used making them susceptible to frequency congestion, which can cause the UAS to lose communication with the ground station due to signal interference (Barnhart, Shappee, & Marshall, 2012). Similar disadvantages exist with beyond line-of-sight. There are often signal blockages by terrain and on-the-move impairments. The size and low altitudes of flight make locating and tracking drones quite difficult. This deficiency in current technology makes it challenging to manage an increasing number of recreational drones. Advances in airborne broadband technology hold the promise of enabling cost-effective communications to aid situational awareness on the ground for military reconnaissance, border patrols, and other government and commercial applications (Hughes, 2013).

The PrecisionHawk announced its LATAS (Low Altitude Tracking and Avoidance System) solution for UASs earlier this year at the Academy of Model Aeronautics Expo. The LATAS system can provide flight planning, tracking, and avoidance for all airborne UASs. Its requirements for operation include nothing more than the use of existing cellular networks. The system size is that of a small chip in the UAS's circuit that would allow verification safety of flight paths and report information to the FAA. It would also enable UAS operation beyond line of sight without the fear of crashing. The PrecisionHawk along with the LATAS technology definitely offer commercial application. The company has been touring the country showcasing its technology at events like the Ohio State Farm Science Review. The UAS flew over Molly Caren Agricultural Center in London, Ohio, in live demonstrations during FSR, which is an expo for displaying cutting-edge farm equipment (PrecisionHawk, 2014). PrecisionHawk was advertised as a new tool for farmers to survey land.

There are some human factor concerns with the use of LOS and BLOS. The launch phase for a particular UAS can be conducted using LOS, transferred to BLOS, then transferred back to LOS for recovery. This can be quite concerning as BLOS operations often have a delay that can last several seconds once a command is sent to the aircraft. Decreased situational awareness is a human factor issue that can arise when switching control from LOS to BLOS. In addition, the increased potential for mode errors becomes a factor during this process. The handoff from LOS to BLOS or vice versa is full of potential for error and communication or control breakdowns.

References

Barnhart, R. K., Shappee, E., and Marshall, D. M. (2012). Introduction to unmanned aircraft systems. New York, NY: CRC Publishing.

Higgins, S. (2015). Taking UAVs Beyond Line of Sight. SPAR Point Group. Retrieved from http://www.sparpointgroup.com/sean-higgins/vol13no2-taking-uavs-beyond-line-of-sight

Hughes. (2013.). Communications beyond line of sight. Retrieved from  http://defense.hughes.com/resources/communications-beyond-the-line-of-sight

PrecisionHawk. (2014, July 16). From military strikes to farming, drones segueing into rural America. Retrieved from http://media.precisionhawk.com/topic/from-military-strikes-to-farming-drones-segueing-into-rural-america/