Sampled Encounters of Low Altitude Manned Aircraft

Summary

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.

Description

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 tCPA and sample_time are encounter parameters from em-pairing-uncor-importancesampling. The tCPA variable the desired time at which the closest point of approach occurs and sample_time variable is the desired total duration of the encounter in seconds. The sample_time value must be greater than tCPA. The other sheet, fixed_paramters, documents the fixed encounter parameters. The minimum initial horizontal and vertical separation requirements were defined by R_min and H_min. 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 encIds denote that 100,000 encounters were generated for each set and that the random seed (randSeed) was set to one.

Distribution Statement

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© 2021 Massachusetts Institute of Technology.

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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.

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