The Global Dragon Radar is a type of Dragon Radar that is a giant map of the Earth that only reveals each general area of the 7 Dragon Balls and it is used by Emperor Pilaf and the Pilaf Gang, and also King Piccolo and the Red Ribbon Army. It does not show the exact spot of where the Dragon Ball is, unlike Bulma's Dragon Radar. The Red Ribbon Army have one in their command room at their main headquarters, which is where they were able to follow Goku.
In Dragon Ball: Mystical Adventure, Master Shen has Pilaf, Shu and Mai build one for him. Pilaf and his gang have a Global Dragon Radar in their airship, which they use to help King Piccolo and his "sons" find the Dragon Balls.