TrajAir: A General Aviation Trajectory Dataset

General Aviation (GA) comprises all civil flights except scheduled passenger airline services. More than 90% of the roughly 220,000 civil aircraft registered in the United States (US) are GA aircraft. In contrast with airline service aircraft which operate with two pilots in a structured higher-altitude operational envelope, GA aircraft are often individually piloted in a more unstructured lower-altitude environment. This low altitude environment is also where a bulk of the next generation of Uncrewed Aerial Vehicles (UAVs) are expected to operate. These UAVs are expected to seamlessly interact with other UAVs and manned air traffic operating in this shared airspace. Nowhere is this manned-manned and potentially unmanned-manned interaction more pronounced than in low-altitude terminal airspace around airports. Low altitudes, multi-agent close-proximity interactions, dynamically changing conditions, and rapid decision making are hallmarks of this type of airspace as compared to en-route airspace where agents are typically well-separated.This dataset contains aircraft trajectories in an untowered terminal airspace collected over 8 months surrounding the Pittsburgh-Butler Regional Airport [ICAO:KBTP], a single runway GA airport, 10 miles North of the city of Pittsburgh, Pennsylvania. The trajectory data is recorded using an on-site setup that includes an ADS-B receiver. The trajectory data provided spans days from 18 Sept 2020 till 23 Apr 2021 and includes a total of 111 days of data discounting downtime, repairs, and bad weather days with no traffic. Data is collected starting at 1:00 AM local time to 11:00 PM local time. The dataset uses an Automatic Dependent Surveillance-Broadcast (ADS-B) receiver placed within the airport premises to capture the trajectory data. The receiver uses both the 1090 MHz and 978 MHz frequencies to listen to these broadcasts. The ADS-B uses satellite navigation to produce accurate location and timestamp for the targets which is recorded on-site using our custom setup. Weather data during the data collection time period is also included for environmental context. The weather data is obtained post-hoc using the METeorological Aerodrome Reports (METAR) strings generated by the Automated Weather Observing System (AWOS) system at KBTP. The raw METAR string is then appended to the raw trajectory data by matching the closest UTC timestamps.We also provide processed data that filters, interpolates and transforms data from a global frame to an airport-centred inertial frame. The inertial frame is centred at one end of the runway with the x-axis along the runway. Trajectories are filtered with aircrafts under 6000 ft MSL and around a 5km radius around the airport origin. We also remove duplicates and interpolate data every second. The proceed files also contain wind-data; a crucial factor in decision-making; separated in components along and perpendicular to the runway direction.<b>More Information and Supplemental Tools</b>Please visit http://theairlab.org/trajair/ for more information.<br>

通用航空（General Aviation, GA）指除定期客运航空服务之外的所有民用飞行活动。美国登记在册的约22万架民用航空器中，超过90%为通用航空航空器。与需两名飞行员在结构化高空作业空域运行的客运航空航空器不同，通用航空航空器通常由单人驾驶，作业于更具非结构化特征的低空环境中。而下一代无人飞行器（Uncrewed Aerial Vehicles, UAVs）的主流运行空域也正是这类低空环境，预计这些无人飞行器将与共享该空域的其他无人飞行器及载人航空器实现无缝交互。在机场周边的低空终端空域中，载人-载人乃至潜在的无人-载人交互表现得最为显著。相较于航路空域中航空器通常保持较大间距的运行场景，该类空域的典型特征为低空运行、多智能体近距离交互、动态变化的环境条件以及快速决策需求。
本数据集包含美国宾夕法尼亚州匹兹堡以北10英里的单跑道通用航空机场——匹兹堡-巴特勒地区机场（ICAO:KBTP）周边无塔台终端空域的航空器航迹数据，采集周期为8个月。航迹数据通过部署于机场场内的自动相关监视广播（Automatic Dependent Surveillance-Broadcast, ADS-B）接收系统记录。本次采集的航迹数据覆盖2020年9月18日至2021年4月23日，共计111个有效采集日，已剔除停机维护、天气恶劣无航班的时段。数据采集时段为当地时间每日1:00至23:00。
该接收系统同时使用1090 MHz与978 MHz频段接收广播信号，自动相关监视广播系统依托卫星导航为目标提供精准位置与时间戳信息，由我们的定制化采集设备现场记录。数据集还包含采集时段内的气象数据以提供环境背景信息，此类气象数据通过事后获取KBTP机场自动气象观测系统（Automated Weather Observing System, AWOS）生成的机场气象报告（METeorological Aerodrome Reports, METAR）字符串得到，通过匹配最接近的UTC时间戳，将原始METAR字符串追加至原始航迹数据中。
此外，本数据集还提供经过预处理的数据：包括对原始数据进行滤波、插值，并将坐标系从全球坐标系转换为以机场为中心的惯性坐标系。该惯性坐标系以跑道一端为原点，x轴沿跑道方向延伸。预处理时将飞行高度低于6000英尺平均海平面高度（Mean Sea Level, MSL）、且位于机场周边5公里范围内的航空器航迹纳入筛选范围，同时剔除重复数据，并将航迹数据按每秒一次的频率进行插值。预处理文件中还包含风场数据——这是决策过程中的关键因素——数据按沿跑道方向与垂直跑道方向的分量分别存储。
<b>更多信息与补充工具</b>请访问http://theairlab.org/trajair/ 获取详细内容。<br>