GPS is the modern answer to the ancient question about one’s place in the world yet it has its limitations. It depends on the time of flight of radio signals emitted by satellites twenty ...

Also called a "differential GPS" (DGPS), an augmentation system compensates for those discrepancies by transmitting corrections to the GPS receivers either via satellite or terrestrial radio.

announced it has been awarded a contract from the Finnish Board of Navigation (FBoN) to provide reference station and integrity monitors for the radiobeacon-based differential GPS (DGPS ...