# Method to Characterize Potential UAS Encounters Using Open Source Data
## 2 Materials and Methods
### Use Cases and Data Sources  
We evaluated use case pairs for sixteen locations. These areas include all locations associated with the UAS Integration Pilot Program (IPP) ([[https://www.faa.gov/uas/programs_partnerships/integration_pilot_program/](https://www.faa.gov/uas/programs_partnerships/integration_pilot_program/)]([https://www.faa.gov/uas/programs_partnerships/integration_pilot_program/](https://www.faa.gov/uas/programs_partnerships/integration_pilot_program/))), majority of states with FAA UAS test sites ([[https://www.faa.gov/uas/programs_partnerships/test_sites/](https://www.faa.gov/uas/programs_partnerships/test_sites/)]([https://www.faa.gov/uas/programs_partnerships/test_sites/](https://www.faa.gov/uas/programs_partnerships/test_sites/))), a few states within FEMA Region 1, and the territorial island of Puerto Rico. All geospatial data used were freely sourced from the public domain. For locations, their administrative boundaries were sourced from Natural Earth Data at a 1:10m scale. The analysis focused primarily on UAS inspections as long linear infrastructure [14; 15; 16] and point obstacles. These realistic use cases are some the most mature and well understood UAS operations, as indicated by their evaluation as part of the UAS IPP, FAA UAS test site, or FAA Pathfinder activities. Point features were sourced from the FAA digital obstacle file (DOF) ([[https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/](https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/)]([https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/](https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/))) and locations of 6300 wind turbines were sourced from the United States Wind Turbine Database [17]. While the FAA DOF may include wind turbines, we wanted to assess the sensitivity of the results between a general (FAA DOF) and a specific dataset (USWTDB). Specifically, the FAA DOF had 483,279 obstacles but we only considered the 321,699 obstacles that were at least 50 feet tall. The software to parse the FAA DOF has been released under a permissive open source license ([[https://github.com/Airspace-Encounter-Models/em-core/tree/master/matlab/utilities-1](https://github.com/Airspace-Encounter-Models/em-core/tree/master/matlab/utilities-1) stparty/faadof]([https://github.com/Airspace-Encounter-Models/em-core/tree/master/matlab/utilities-1](https://github.com/Airspace-Encounter-Models/em-core/tree/master/matlab/utilities-1) stparty/faadof)). Electric power transmission lines operating at high voltages of 69-765 kV were sourced from the U.S. Department of Homeland Security (DHS) Homeland Infrastructure Foundation Level Data (HIFLD) ([[https://hifld-geoplatform.opendata.arcgis.com/datasets/electric-power-transmission-lines](https://hifld-geoplatform.opendata.arcgis.com/datasets/electric-power-transmission-lines)]([https://hifld-geoplatform.opendata.arcgis.com/datasets/electric-power-transmission-lines](https://hifld-geoplatform.opendata.arcgis.com/datasets/electric-power-transmission-lines))). Regular railway tracks were sourced from the Geofabrik OSM extracts ([[https://download.geofabrik.de/north-america.html](https://download.geofabrik.de/north-america.html)]([https://download.geofabrik.de/north-america.html](https://download.geofabrik.de/north-america.html))). Four types of pipelines (crude oil, hydrocarbon gas liquids, natural gas, and petroleum products) were sourced from the U.S. Energy Information Administration (EIA) ([[https://www.eia.gov/maps/map_data/CrudeOil_Pipelines_US_EIA.zip](https://www.eia.gov/maps/map_data/CrudeOil_Pipelines_US_EIA.zip)]([https://www.eia.gov/maps/map_data/CrudeOil_Pipelines_US_EIA.zip](https://www.eia.gov/maps/map_data/CrudeOil_Pipelines_US_EIA.zip))).