I think there should be more than one type of scanner - for example, maybe a positioning scanner which gave you your location and the location of things around you and let you plot waypoints. Then you could have a sensor, which would give you detailed information on entities - composition, armaments, shielding, etc. depending on how many sensors you had. Then you could have a bioscanner, which would tell you how many life forms were aboard a ship or on a planet.