An Automatic Identification System reporting system for tracking a plurality of maritime vessels in cooperation with a constellation of Low-Earth Orbit satellites, each LEO satellite comprising an AIS payload for receiving AIS messages from the plurality of maritime vessels and determining therefrom reported vessel position data and satellite-based observation data, wherein the reported maritime vessel position data is based upon a Global Positioning System, GPS, wherein the satellite-based observation data includes at least one of a Doppler band or a time-of-arrival, the AIS reporting system comprising: an AIS processor and memory cooperating therewith and configured to obtain the reported maritime vessel position data and satellite-based observation data from the constellation of LEO satellites over time, and filter, using a Kalman filter, the reported maritime vessel position data and satellite-based observation data obtained over time, to recursively produce estimated maritime vessel positions and update the estimated maritime vessel positions for the plurality of maritime vessels, wherein the AIS processor is configured to identify a position misreporting maritime vessel based upon the updated estimated maritime vessel positions for the plurality of maritime vessels, wherein upon identification of a position misreporting maritime vessel, said AIS processor is configured to prioritize the processing of the AIS messages from the position misreporting maritime vessel, wherein said AIS processor is configured to determine a plurality of position misreporting maritime vessels in a geographic area, wherein the AIS processor indicates the presence of GPS signal jamming based on the determination of the plurality of position misreporting maritime vessels in a geographic area, and characterized in that if time of arrival information is not available from the satellite-based observation data, the AIS reporting system is configured to calculate as if the reported position and a velocity of a maritime vessel of the plurality of maritime vessels is within a Doppler band and/or computes a level of confidence in the reported position. obtain the reported maritime vessel position data and satellite-based observation data from the constellation of LEO satellites over time, and filter, using a Kalman filter, the reported maritime vessel position data and satellite-based observation data obtained over time, to recursively produce estimated maritime vessel positions and update the estimated maritime vessel positions for the plurality of maritime vessels, wherein the AIS processor is configured to identify a position misreporting maritime vessel based upon the updated estimated maritime vessel positions for the plurality of maritime vessels, wherein upon identification of a position misreporting maritime vessel, said AIS processor is configured to prioritize the processing of the AIS messages from the position misreporting maritime vessel, wherein said AIS processor is configured to determine a plurality of position misreporting maritime vessels in a geographic area, wherein the AIS processor indicates the presence of GPS signal jamming based on the determination of the plurality of position misreporting maritime vessels in a geographic area, and characterized in that if time of arrival information is not available from the satellite-based observation data, the AIS reporting system is configured to calculate as if the reported position and a velocity of a maritime vessel of the plurality of maritime vessels is within a Doppler band and/or computes a level of confidence in the reported position.