航线规划、船只避碰研究场景船舶会遇概率信息数据

该数据为二次加工数据，以舟山马峙锚地附近海区为采集区域，采集2019年10月31日-2022年4月30日的AIS数据，分析区域中的船只会遇关系，得到水域会遇概率密度分布。数据可用于航线规划、船只避碰研究等场景。1.取采样时间和区域内的AIS数据，整理成AIS轨迹。2.对AIS轨迹进行不同时刻的会遇分析。具体做法是：取固定间隔的分析时间点，在每个分析时间点上对AIS轨迹进行插值，推算出在该时刻AIS目标的位置；然后依据时间临近的轨迹点推算出该时刻AIS目标的速度和航向；根据AIS目标的位置、速度和航向，分别得到该目标在△T、2△T、3△T后所在位置的概率椭圆；分析△T、2△T、3△T后所有概率椭圆的位置关系，如果存在交叠，取交叠区域几何中心所在网格为会遇点位，该会遇点位会遇概率加1；记录所有分析时间点的会遇概率并进行存储。

This is a secondary processed dataset. The data collection area is the sea area near the Mashi Anchorage in Zhoushan. AIS data spanning from October 31, 2019 to April 30, 2022 were collected, and ship encounter relationships within the area were analyzed to generate the encounter probability density distribution of the water area. This dataset can be applied to scenarios including route planning and ship collision avoidance research.
1. Retrieve AIS data within the specified sampling time frame and target area, and organize the data into standardized AIS trajectories.
2. Perform encounter analysis on AIS trajectories at different time points. The detailed procedure is as follows:
1) Select analysis time points with fixed intervals;
2) For each analysis time point, interpolate the AIS trajectories to calculate the position of each AIS target at this moment;
3) Infer the speed and course of each AIS target at this moment based on the temporally adjacent trajectory points;
4) For each AIS target, derive the probability ellipse corresponding to its position after △T, 2△T and 3△T respectively based on its current position, speed and course;
5) Analyze the positional relationship of all probability ellipses after △T, 2△T and 3△T. If there is an overlapping area, take the grid where the geometric center of the overlapping area lies as the encounter point, and increase the encounter probability of this point by 1;
6) Record and store the encounter probabilities of all analysis time points.