In the satellite view of gpsapp, is the number right above the speed the altitude? This number never changes and is always dim. I thought that if you had 4 or more signals, then gps could give your altitude as well as coordinates. Do not all gps recievers give altitude or is there an option I have to set for this or what? And also what do all the other numbers on this screen stand for? From top to bottom... coordinates, then I think the altitude, then speed, then something that has a number then says HD, then something that says 2D, then i think the number of sattelite signals and SV. What do all these things mean?