2.3-Blog: Unmanned Aerial Systems

In this activity, you will create a blot post identifying a specific category associated with the integration of unmanned aerial systems (UAS) into the National Airspace System (NAS; e.g., sense and avoid [SAA]). Research information about the legislative and technological requirements that have been (or are expected to be) put in place to accommodate the identified category. Remember to focus your research on a single aspect of UAS integration (e.g., lost link, see/sense and avoid, automated operation, etc.). You are encouraged to find multiple sources of information to support your blog post.

Detect, Sense, and Avoid Technology

            There are many challenges associated with unmanned aerial systems (UAS) integration into the national airspace system (NAS). The number of UAS in the United States is growing at a rapid pace due to many small systems being cheap and easily accessible. These challenges appear to be centered on the lack of detect, sense, and avoid technology. According to Kim Williams, the former head of the Federal Aviation Administration’s (FAA) UAS integration office, detect and avoid is the biggest technical hurdle when it comes to integration of UAS into the NAS (Echodyne, 2016). With unmanned aircraft operating near manned aircraft, UAS must have some sort of detection system that warns the operator about oncoming traffic or nearby traffic that could cause an accident. Detect, sense, and avoid technology is the solution to preventing accidents between unmanned aircraft and manned aircraft alike. This technology should allow autonomous UAS to avoid obstacles and other aircraft and should also alert the operator of any potential hazards within the surrounding airspace to prevent accidents. The current issue with detect, sense, and avoid technology is that civilian UAS do not have this valuable technology implemented into the system software. Due to increasing numbers of UAS in the skies in the United States, the FAA understands that the need for detect, sense, and avoid technology is vital to maintaining the safety levels within the NAS.

            Legislation for detect, sense, and avoid technology is still being created. The legislation that must be kept in mind coincides with manned aircraft flight rules. 14 Code of Federal Regulations (CFR) 91 subpart B outlines specific requirements for basic flight within the NAS. Without detect, sense, and avoid technology, UAS cannot follow the regulations listed in 14 CFR 91,113 which contains information about the right of way rules for aircraft. For example, UAS cannot currently maintain vigilance during flight and also cannot follow right of way rules. An issue that must be addressed in the near future is how UAS will be classified in the NAS. Will they have their own class (such as balloon, glider, airship, or aircraft) and how will right of way rules be designed if UAS have their own class? According to 14 CFR 91.113, the pilot of an aircraft should see and avoid other aircraft in the same airspace (14 CFR 91.113, n.d.). Without detect, sense, and avoid technology, the operator of a UAS would be required to follow basic right of way rules. This could prove to be difficult due to bandwidth limitations between the ground control station (GCS) and the UAS, line of sight or beyond line of sight operations, the weather conditions present at the time of UAS flight, and the size of the screen the operator is using to conduct a flight.

            There are several solutions available that could act as detect, sense, and avoid technology, but ADS-B appears to be the primary choice. ADS-B is a growing technology and will play a big role in the transformation of the NAS into the NextGen system. ADS-B has been designed to allow individual aircraft to report their global positioning system (GPS) locations within a networked environment (Zimmerman, 2013). Continuous updates to aircraft position will allow pilots of manned aircraft and operators of UAS to have better situational awareness regarding the positioning of other aircraft. According to Zhao, Gu, Hu, Lyu, & Wang (2016), ADS-B is of great interest due to its small size, low weight, and low power consumption when compared to other alternatives to ADS-B. ADS-B would be a viable option due to its low costs and lightweight components; however, ADS-B could prove difficult to implement due to integrity, confidentiality, and availability (Sampigethaya & Pooyendran, 2012). Another issue that is present with ADS-B is that this technology cannot detect things such birds, power lines, communications towers, or aircraft without ADS-B. This is a severe limitation that could prove to be dangerous for the manned aircraft/UAS and people on the ground.

            While ADS-B is a viable option if all manned aircraft and UAS are required to have it equipped on-board, this will not always be the case. There are several companies that are developing a radar based sense and avoid system that would be able to detect all hazards during flight, not just other aircraft equipped with ADS-B. Echodyne is a business that creates radar and utilizes high performance scanning radars to detect hazardous for various vehicles. Radar is the only sensor that can reliably perform all detect, sense, and avoid responsibilities in all weather conditions and ranges for safe UAS operation in the NAS (Echodyne, 2016). Echodyne has developed a radar system for small and media sized UAS to electronically scan for all hazards within the field of view of the UAS. This emerging technology could prove to be a more reliable technology when it comes to UAS integration into the NAS. Future developments of detect, sense, and avoid technology could be centered around radar based systems due to the ability of both the UAS and the operator to see all hazards in the surround airspace, not just other aircraft equipped with technology such as ADS-B.

            The mission planning and control station (MPCS) will be a critical element when detect, sense, and avoid technology is implemented into UAS. The MPCS will allow the operator to monitor the payloads of the UAS (ADS-B or on-board radar) along with other critical information seen on the cameras and other sensors. For UAS operations in which an operator is in direct control of the UAS, the MPCS should contain the means to receive the down coming signal from the UAS while also being able to display the information that is being collected by the payload. The MPCS should also allow the operator to playback the recorded video. For civilian operators, a memory card and capable computer should be purchased so all sensor information could be captured and replayed as necessary. This would also allow the data captured to be edited for further analysis (Fahlstrom & Gleason, 2012).

 

References

Echodyne. (2016, May 2). Echodyne Announces Development of Airborne Detect and Avoid Radar for Small Unmanned Aircraft Systems. Retrieved from http://echodyne.com/echodyne-announces-development-of-airborne-detect-and-avoid-radar-for-small-unmanned-aircraft-systems/

Fahlstrom, P. G., & Gleason, T. J. (2012). Introduction to UAV systems (4th ed.). Chichester: Wiley.

Sampigethaya, R., & Poovendran, R. (2012). Enhancing ADS-B for future UAV operations. doi:10.2514/6.2012-2420

Zhao, C., Gu, J., Hu, J., Lyu, Y., & Wang, D. (2016). Research on cooperative sense and avoid    approaches based on ADS-B for unmanned aerial vehicle. Presented at the 2016 IEEE Chinese Guidance, Navigation, and Control Conference, Nanjing, China.             doi:10.1109/CGNCC.2016.7829019

Zimmerman, J. (2013, January 17). ADS-B 101: what it is and why you should care. Retrieved from http://airfactsjournal.com/2013/01/ads-b-101-what-it-is-and-why-you-should-care/

14 CFR 91.113 - Right-of-way rules: Except water operations. (n.d.). Retrieved from https://www.law.cornell.edu/cfr/text/14/91.113