GEOG 201 Lecture 3: 3#GPS
Document Summary
The original gps is satellite - based navigation system made up of a network of satellites. Put into orbit by the u. s department of defence. Sateliteds are constantly moving and can complete two orbit in under 24 hrs. Orbiting satellites transmit position and time data. Handheld receivers calculate latitude, longitude, altitude , velocity. Components of the gps system: space segment, 24-43 satellites, 6 orbital planes(inclined 55 degrees with respect to equator; orbits separated by 60degrees), 20,000 km elevation above earth, 5-8 satellites visible from any point on earth, satellites send: Piece of the almanac: approximate orbits of all satellites and additional info such as. Utc time correction(utc: coordinated universal time: user segment-main. Four satellites are to compute the 4d of x,y,z(position) and time, 6should be in view at all times, 8-9being an average number. Position in latitude/longitude expressed in degrees and minutes (or deg, min, sec ) Time in utc: ground control segment. Distance from user to satellite: distance measurement.
