Trimble and Saab TransponderTech AB are cooperating to integrate their differential GPS (DGPS) solutions for enhanced marine navigation. Saab and Trimble will integrate their marine navigation solutions to deliver DGPS error correction messages to ships at sea through automatic identification system (AIS) coast stations and networks. The DGPS messages transmitted on AIS frequencies will augment the existing marine DGPS broadcasts from coastal beacon stations. The two companies are collaborating to develop interfaces connecting Saab's AIS and Vessel Tracking Management & Information System (VTMIS) with Trimble DGPS reference station and integrity monitoring software.