우림 텍 Space Eye _ AIS 
 AIS is a VHF short range transponder system designed for ship collision avoidance . The range is determined by line of sight . The transmissions include position , course and the ship ' s Maritime Mobile Service Identity ( MMSI ) number , which in principle is unique to each ship . There are databases relating the MMSI number to the ship name . In addition information is transmitted about the destination and the cargo . Thus this information is invaluable for maritime surveillance . For example , the economy of Panama is very dependent on the Canal as described in " Panama Canal ". The Canal is also very important for the world economy . 
 AIS is fundamentally a self - reporting system and the data is sometimes in error by accident or design . For example the MMSI number may have a default value or have been entered incorrectly . Therefore AIS data is unreliable for maritime security purposes and it should be verified using data from other sensors , such as satellite - borne SAR . 
 Satellites can be fitted with AIS receivers and ORBCOMM , COMDEV ( through its subsidary company exactEarth ) , SpaceQuest and LuxSpace are currently flying these . 
 ORBCOMM specializes in short messaging sytems and has numerous satellites in orbit , while exactEarth has several with AIS receivers on board . To achieve global AIS coverage with a latency of about 10 minutes about 30 satellites are required . A number of consortia have been formed to control costs and their membership appears to be broadening . For example ORBCOMM is partnered with LuxSpace and SpaceQuest with exactEarth . COMDEV Europe ( UK ) and LuxSpace participated in the Pasta Mare Project . 
 A presentation on the cross - validation of of AIS signals with RADARSAT ship detections by data fusion is available : J . K . E . Tunaley , " Polar - Epsilon and Canadian MDA ", June 2006 . This was given at an NDIA conference organized by the USCG , " Maritime Domain Awareness Requirements , Capabilities and Technology Forum , Tampa , Florida . When comparing AIS reports with the positions of ships in a Synthetic Aperture Radar ( SAR ) image , it is important to correct the apparent ship position in the image for " Velocity Bunching ". A simple derivation for this is provided in J . K . E . Tunaley , " SAR Velocity Bunching Relationships ", LRDC Report , April , 2009 .