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As unmanned aerial systems (UASs) increasingly integrate into the US national airspace system, there is an increasing need to characterize how commercial and recreational UASs may encounter each other. To inform the development and evaluation of safety critical technologies, we demonstrate a methodology to analytically calculate all potential relat...
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... assess the sensitivity of the results to the spacing between interpolated points, we repeated the analysis for one of the largest USA states, California, using a 100 instead of a 500 foot spacing. Shown by Table 4, the percent difference (given two numbers, a and b), for the computation time, mean, and median was calculated as There was mostly a negligible difference between the mean and median statistics when comparing the use of 100 and 500 feet. However, there was a significant percent increase in the required computation time due to the increased quantity of points to consider. ...Similar publications
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... Midair collision risk models in aviation have evolved from early deterministic approaches, which relied on specific scenarios [21,22,23], to more complex probabilistic models like the Collision Risk Model (CRM) used by ICAO [24]. Modern techniques [25,26,27] employ Monte Carlo simulations for statistical outcomes, agent-based models [28,29] to simulate individual aircraft behaviors, and Bayesian Networks [30,31] to capture interdependencies in aviation operations. Furthermore, as aviation technologies such as Automatic Dependent Surveillance-Broadcast (ADS-B) become more prevalent, risk models are revised and refined to encompass model validation using real-world data. ...
The airspace environment is expected to continue increasing in complexity with the introduction of new types of air vehicles and operations and the projected growth of air traffic volumes. This creates a need for the development of new models to better understand the potential future states. This paper presents a geospatial model of a complex airspace environment which can be used to study any geospatially distributed entity within it. The methodology leverages Discrete Global Grid Systems (DGGS), a Geographic Information Systems framework previously utilized in the fields of geography and urban planning. The
usefulness of the model is demonstrated on a case study that maps the geospatial evolution of the risk of
midair collisions as a function of 3D location for four scenarios of increasing complexity in an airspace region of interest. The results from these four scenarios showed that the proposed methodology can be used to study the risk of midair collisions for different points in the airspace for any type of air vehicle and airspace region in a fully three-dimensional model that is capable of performing time-varying analysis in a computationally efficient manner.
... Trajectory waypoints followed the terrain and tried to maintain a constant altitude with a tolerance of 25 feet. The initial separation between aircraft and encounter parameters were informed by an analytical assessment of all potential relative geometries between long linear infrastructure features for sixteen USA locations [63]. Table 4 documents the encounter configuration and aircraft parameters where airspeed was sampled from a uniform distribution. ...
... Ten waypoint combinations were selected s o that horizontal separation was 0.6 nautical miles or less 30 seconds after the start of the encounter. The 0.6 nautical mile threshold was based on a previous geometric assessment of long linear infrastructure [63]. For each combination, airspeed and altitudes were sampled for both aircraft and the trajectories were generated. ...
The capability to avoid other air traffic is a fundamental component of the layered conflict management system to ensure safe and efficient operations in the National Airspace System. The evaluation of systems designed to mitigate the risk of midair collisions of manned aircraft are based on large-scale modeling and simulation efforts and a quantitative volume defined as a near midair collision (NMAC). Since midair collisions are difficult to observe in simulation and are inherently rare events, basing evaluations on NMAC enables a more robust statistical analysis. However, an NMAC and its underlying assumptions for assessing close encounters with manned aircraft do not adequately consider the different characteristics of smaller UAS-only encounters. The primary contribution of this paper is to explore quantitative criteria to use when simulating two or more smaller UASs in sufficiently close proximity that a midair collision might reasonably occur and without any mitigations to reduce the likelihood of a midair collision. The criteria assumes a historically motivated upper bound for the collision likelihood and subsequently identify the smallest possible NMAC analogs. We also demonstrate the NMAC analogs can be used to support modeling and simulation activities.
