DOI: 10.5281/zenodo.5237349
title: Sampled Encounters of Low Altitude Manned Aircraft

description: <strong>Summary</strong> Paired encounters between two manned aircraft based on samples from Bayesian dynamic models of aircraft behavior. The encounters are uncorrelated in the sense that it is assumed that air traffic control services are not being provided during the encounter. <strong>Description</strong> For many aviation safety studies, aircraft behavior is represented using encounter models, which are statistical models of how aircraft behave during close encounters. They are used to provide a realistic representation of the range of encounter flight dynamics where an aircraft collision avoidance system would be likely to alert. These models represent aircraft behavior (rates) during the course of the encounter with other aircraft. Encounter models have been developed for many different manned operational contexts. For more details on encounter models, please refer to the overview on the Airspace Encounter Models GitHub organization: https://github.com/Airspace-Encounter-Models/em-overview. The Bayesian models were sourced from v1.3 of the em-model-manned-bayes repository while v1.2 of em-pairing-uncor-importancesampling contained the software to pair samples from the Bayesian models to create encounters. This dataset contains 1.6 million encounters across 18 different encounter sets, each consisting of 100,000 unique encounters. The encounters were generated in June 2021. Please refer to the software for details on the format and variables for each encounter. The dataset is provided as a single .zip archive with multiple directories. Simply download the .zip file and extract. An excel file with two sheets are document the configuration parameters. The first sheet reports the tradespace and configurations for each encounter set. The model files correspond to Bayesian models from em-model-manned-bayes, while <em>tCPA</em> and <em>sample_time</em> are encounter parameters from em-pairing-uncor-importancesampling. The <em>tCPA </em>variable the desired time at which the closest point of approach occurs and <em>sample_time</em> variable is the desired total duration of the encounter in seconds. The <em>sample_time</em> value must be greater than <em>tCPA</em>. The other sheet, <em>fixed_paramters</em>, documents the fixed encounter parameters. The minimum initial horizontal and vertical separation requirements were defined by <em>R_min</em> and <em>H_min</em>. The bin edges and desired proportions defined the importance sampling criteria for the horizontal miss distance (HMD) and vertical miss distance (VMD) at the closest point of approach. The <em>encIds</em> denote that 100,000 encounters were generated for each set and that the random seed (<em>randSeed</em>) was set to one. <strong>Distribution Statement</strong> DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. © 2021 Massachusetts Institute of Technology. Delivered to the U.S. Government with Unlimited Rights, as defined in DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any copyright notice, U.S. Government rights in this work are defined by DFARS 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work other than as specifically authorized by the U.S. Government may violate any copyrights that exist in this work. This material is based upon work supported by the Federal Aviation Administration under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Federal Aviation Administration. This document is derived from work done for the FAA (and possibly others); it is not the direct product of work done for the FAA. The information provided herein may include content supplied by third parties. Although the data and information contained herein has been produced or processed from sources believed to be reliable, the Federal Aviation Administration makes no warranty, expressed or implied, regarding the accuracy, adequacy, completeness, legality, reliability or usefulness of any information, conclusions or recommendations provided herein. Distribution of the information contained herein does not constitute an endorsement or warranty of the data or information provided herein by the Federal Aviation Administration or the U.S. Department of Transportation. Neither the Federal Aviation Administration nor the U.S. Department of Transportation shall be held liable for any improper or incorrect use of the information contained herein and assumes no responsibility for anyone’s use of the information. The Federal Aviation Administration and U.S. Department of Transportation shall not be liable for any claim for any loss, harm, or other damages arising from access to or use of data or information, including without limitation any direct, indirect, incidental, exemplary, special or consequential damages, even if advised of the possibility of such damages. The Federal Aviation Administration shall not be liable to anyone for any decision made or action taken, or not taken, in reliance on the information contained herein.