Automatic Identification System (AIS) Announcements
The following are updates and announcements for AIS users:
- User names and passwords will now expire one year after being issued.
- Please read the AIS standards and specifications provided by the Coast Guard to learn what are valid domains and other content issues for each field.
- The metadata for 2009, 2010 and 2011 reports that the speed over ground (SOG) and the course over ground (COG) values are at a resolution of 1/10ths of units; the unit resolution should read “whole units”. These are knot and degree values respectively.
- Some users report errors when using the Track Builder tool under certain circumstances. Our testing indicates this is caused when low-level geoprocessing tasks get completed before the hard disk device is available. Configurations with higher speed (10,000 RPM) disks do not exhibit this error.
- The Filter and Format tools that are used to process the raw NMEA provided by the Coast Guard use the AIS Parser written by Brian C. Lane.
- The June 2009 data set is incomplete
- These data have been filtered to a one minute sample rate
- The MMSI values for 2010 and 2011 have been encrypted at the request of the Coast Guard