TY - RPRT TI - Airspace Safety Threshold Study: NAS-Wide Encounter Rate Evaluation Using Historical Radar Data and ACES AU - Johnson, Marcus A. AU - Thipphavong, David P. AU - Park, Chunki AU - Santiago, Confesor AU - Mueller, Eric PY - 2015 UR - https://ntrs.nasa.gov/citations/20190027491 ID - 20190027491 ER -