Marcq St. Hilaire method uses six celestial body sights at twilight. Sun-run-sun technique requires multiple sightings spaced hours apart. Position fix is found where all position lines intersect
GPS satellites broadcast signals for satellite navigation and positioning. GPS constellation operated by US Space Force's 2nd Space Operations Squadron. System uses ranging codes and navigation messages for position determination
GPS is a satellite-based navigation system owned by the US Space Force. Requires four or more satellites for accurate positioning. Operates independently of telephone or internet reception. Provides geolocation and time information worldwide
Right-click on map location to display coordinates in pop-up menu. Coordinates shown in decimal format (e.g. 43.835140893792065, -102.39237003211397). Coordinates can be copied and pasted anywhere
Well-designed GPS receivers can achieve accuracy better than 5m. Dilution of Precision (DOP) measures factors affecting GPS accuracy. PDOP below 1.0 is ideal, below 2.0 is excellent
Position fixing interval determines maximum time between position fixes. Position fixing interval should allow time for course correction. GPS is primary method, radar fix secondary in open sea