AIS data prepared by Statsat AS for May 2020

AIS data prepared and provided by Statsat AS (Norway) in the framework of the T-SAR project (<em>IKTPLUSS programme on reducing digital vulnerabilities, </em><strong>10 MNOK from the Research Council of Norway, Norway</strong>). The dataset contains AIS data (satellite + other) on a global coverage for 2020. There is one zip file and its name is the month (01 for January to 12 for December) ending with '.zip' and the zip file contains zipped Comma Separated Values (CSV) files; one per day. The CSV zipped files are named with the following convention: ais_YYYYMMDD.zip where YYYY is the year (here 2020), MM the month (01 to 12) and DD the day (01 to 31 depending on the month). For instance, ais_20200101.zip contains one single CSV file called ais_20200101.csv that corresponds to the 1st January 2020. The csv files have one header line: mmsi;lon;lat;date_time_utc;sog;cog;true_heading;nav_status;rot;message_nr;source where: <strong>mmii</strong> integer MMSI number of the vessel (AIS identifier). All records belonging to the same vessel will have the same identifier. <strong>lon</strong> float Geographical longitude (WGS84) between -180 to 180 <strong>lat</strong> float Geographical latitude (WGS84) between -90 to 90 <strong>date_time_utc</strong> datetime Date and Time (in UTC) when position was recorded by AIS. It is represented as: YYYY-MM-DD HH:MM:SS (for instance 2020-01-01 00:00:00). <strong>sog</strong> float Speed over ground (knots) <strong>cog</strong> float Course over ground (degrees) <strong>true_heading</strong> integer Heading (degrees) of the vessel's hull. A value of 511 indicates there is no heading data. <strong>nav_status</strong> integer Navigation status according to <strong>AIS Specification</strong> <strong>rot</strong> integer rate of turn <strong>message_nr</strong> integer message number <strong>source</strong> integer source is the source of AIS data ('g' for ground or 's' for satellite). One row in the CSV file corresponds to one message.本数据集由挪威Statsat AS在T-SAR项目框架下整理并提供，该项目隶属于IKTPLUSS数字脆弱性减缓计划，由挪威研究理事会资助10 MNOK。本数据集包含2020年全球覆盖范围的自动识别系统（AIS）数据，涵盖卫星及其他来源的数据。数据集共包含12个压缩文件，每个文件以对应月份命名（01代表1月，12代表12月），后缀为.zip。每个月份压缩包内包含按日打包的逗号分隔值（CSV）文件压缩包，每日对应一个压缩包。内部的CSV压缩包遵循以下命名规范：ais_YYYYMMDD.zip，其中YYYY为年份（本数据集为2020），MM为月份（01至12），DD为日期（依月份不同取值为01至31）。例如，ais_20200101.zip内包含单个CSV文件ais_20200101.csv，对应2020年1月1日的数据。该CSV文件包含一行表头：mmsi;lon;lat;date_time_utc;sog;cog;true_heading;nav_status;rot;message_nr;source，各字段详细说明如下：mmsi：整数型，船舶的MMSI编号（AIS标识符），同一船舶的所有记录将使用相同的标识符；lon：浮点型，WGS84坐标系下的地理经度，取值范围为-180至180；lat：浮点型，WGS84坐标系下的地理纬度，取值范围为-90至90；date_time_utc：日期时间型，AIS记录船舶位置时的UTC日期与时间，格式为YYYY-MM-DD HH:MM:SS（例如2020-01-01 00:00:00）；sog：浮点型，对地航速，单位为节；cog：浮点型，对地航向，单位为度；true_heading：整数型，船舶船体的真实航向，单位为度，取值为511时表示无航向数据；nav_status：整数型，依据AIS规范定义的航行状态；rot：整数型，转向速率；message_nr：整数型，消息编号；source：整数型，AIS数据来源，'g'代表地面基站，'s'代表卫星。CSV文件中的每一行对应一条AIS消息。