A Well Clear Recommendation for Small UAS in High-Density, ADS-B-Enabled Airspace

McLain, Timothy W.; Duffield, Matthew O.

doi:10.2514/6.2017-0908

Cited by 20 publications

(16 citation statements)

References 5 publications

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“…However, TCAS will only issue traffic advisories and no maneuverbased resolution advisories below 1000 ft, rendering this TCAS sensitivity criteria not applicable for low-altitude sUASs. Furthermore, UAS very low level (VLL) operations that are exclusively below 500 ft AGL in any applicable airspace class are currently out of the scope for [36], independent of the SARP. Duffield analyzed sUAS operating in high-density ADS-B airspace and the limitations of 978 MHz ADS-B with respect to well clear.…”

Section: A Previous Work For Large Unmanned Aircraft Systemmentioning

confidence: 99%

Well-Clear Recommendation for Small Unmanned Aircraft Systems Based on Unmitigated Collision Risk

Weinert

Campbell

Vela

et al. 2018

Journal of Air Transportation

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Unmanned aircraft systems must demonstrate a capability to sense and avoid air traffic as part of a layered conflict management system to enable safe operations in the National Airspace System. During operations, an unmanned aircraft system should attempt to remain "well clear" to minimize the need for a collision avoidance action. Previously, a well-clear definition was adopted for large unmanned aircraft systems; however, this definition is not appropriate for small unmanned aircraft system weighing less than 55 lb operating at low altitudes. In response, this paper outlines research toward a definition of well clear for small unmanned aircraft systems, based on airborne collision risk, for midterm concepts of operations at low altitudes in nonterminal airspace.

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Section: A Previous Work For Large Unmanned Aircraft Systemmentioning

confidence: 99%

Well-Clear Recommendation for Small Unmanned Aircraft Systems Based on Unmitigated Collision Risk

Weinert

Campbell

Vela

et al. 2018

Journal of Air Transportation

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“…The false alarm rate can be computed as: (18) where n CA not_collision is the number of conflicts that did not lead to collision; n not_collision is the number of non-collisions. Figure 4 explains how the dynamic CFR adapts to the surrounding airspace environment.…”

Section: B Calculation Of Missing Alarm Rate and False Alarm Ratementioning

confidence: 99%

“…Moreover, Mullins et al designed the dynamic separation threshold for the sense and avoid (SAA) system of the UAS in 2013, replaced the distance-based threshold with time-based threshold, considering the performance of intruding aircraft, and developed a solution with small computing cost using turning geometry [17]. In 2017, Duffield and McLain studied the WC definition for the airspace with dense UAS based on Automatic Dependent Surveillance-Broadcast (ADS-B) [18].…”

Section: Introductionmentioning

confidence: 99%

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

Zhang

2019

IEEE Access

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The key challenge to integrate the unmanned aircraft system (UAS) into airspace is to develop a means to sense and avoid (SAA) other aircrafts. The main function of the SAA is self-separation, i.e. remaining ''well clear'' of the other aircrafts. The separation thresholds must be quantitatively defined for the UAS to autonomously maintain self-separation. In this paper, the separation thresholds are defined quantitatively for the UAS in a dynamic airspace full of aircrafts that differ in motion state and performance. Then, a ''sector-like'' dynamic collision-free region (CFR) was set up around the UAS. The size of the CRF can be adjusted adaptively according to the relative motion states of the surrounding intruders, the performance of the UAS, and the altitude of the airspace. The simulation results show that the proposed adaptive separation thresholds adapted to the dynamic airspace environment better than the fixed separation thresholds recommended by Sense & Avoid Science and Research Panel (SARP), and controlled the missing and false alarm rates on low levels. This means our adaptive separation thresholds can effectively balance the safety and operation efficiency of the airspace. INDEX TERMS Unmanned aircraft system (UAS), airspace integration, well clear (WC), self-separation, collision avoidance, separation thresholds, sense and avoid (SAA).

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“…The DAA approach and design parameter definitions were inherited from [4]. The following DAA design parameter definitions are provided:…”

Section: Daa Model Detailsmentioning

confidence: 99%

“…The purpose of these simulation results is to display the estimated performance of DAA algorithms as we adjust certain parameters. The 'Probability of First Time MSO Receiver Collisions' plot is shown in Figure 11 to display the difference between the estimated closed form equivalent [4] versus the GRC simulation output.…”

Section: Table 7 -A2g Daa Simulation Input Parametersmentioning

confidence: 99%

ADS-B mixed SUAS and NAS system capacity analysis and DAA performance

Matheou

Apaza

Downey

et al. 2018

2018 Integrated Communications, Navigation, Surveillance Conference (ICNS)

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Automatic Dependent Surveillance-Broadcast (ADS-B) technology was introduced more than twenty years ago to improve surveillance within the US National Airspace Space (NAS) as well as in many other countries.Via the NextGen initiative, implementation of ADS-B technology across the US is planned in stages between 2012 and 2025. ADS-B's automatic one second epoch packet transmission exploits on-board GPS-derived navigational information to provide position information, as well as other information including vehicle identification, ground speed, vertical rate and track angle. The purpose of this technology is to improve surveillance data accuracy and provide access to better situational awareness to enable operational benefits such as shorter routes, reduced flight time and fuel burn, and reduced traffic delays, and to allow air traffic controllers to manage aircraft with greater safety margins. Other than the limited amount of information bits per packet that can be sent, ADS-B's other hardlimit limitation is capacity. Small unmanned aircraft systems (sUAS) can utilize limited ADS-B transmission power, in general, thus allowing this technology to be considered for use within a combined NAS and sUAS environment, but the potential number and density of sUAS predicted for future deployment calls into question the ability of ADS-B systems to meet the resulting capacity requirement. Hence, studies to understand potential limitations of ADS-B to fulfill capacity requirements in various sUAS scenarios are of great interest. In this paper we, validate/improve on, previous work performed by the MITRE Corporation concerning sUAS power and capacity in a sUAS and General Aviation (GA) mixed environment. In addition, we implement its inherent media access control layer capacity limitations which was not shown in the MITRE paper. Finally, a simple detect and avoid (DAA) algorithm is implemented to display that ADS-B technology is a viable technology for a mixed NAS/sUAS environment even in proposed larger mixed density environments.

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A Well Clear Recommendation for Small UAS in High-Density, ADS-B-Enabled Airspace

Cited by 20 publications

References 5 publications

Well-Clear Recommendation for Small Unmanned Aircraft Systems Based on Unmitigated Collision Risk

Well-Clear Recommendation for Small Unmanned Aircraft Systems Based on Unmitigated Collision Risk

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

ADS-B mixed SUAS and NAS system capacity analysis and DAA performance

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