Garmin GPS Beginner's Manual - How.Accurate.Is.Gps?
GPS Beginner’s Guide
Ground.Transportation
GPS technology helps with automatic vehicle location and in-vehicle navigation systems. Many navigation systems show the vehicle’s location
on an electronic street map, allowing drivers to keep track of where they are and to look up other destinations. Some systems automatically
create a route and give turn-by-turn directions. GPS technology also helps monitor and plan routes for delivery vans and emergency vehicles.
Marine
GPS technology helps with marine navigation, traffic routing, underwater surveying, navigational hazard location, and mapping. Commercial
fishing fleets use it to navigate to optimum fishing locations and to track fish migrations.
Military
Military aircraft, ships, submarines, tanks, jeeps, and equipment use GPS technology for many purposes including basic navigation, target
designation, close air support, weapon technology, and rendezvous.
Public.Safety
Emergency and other specialty fleets use satellite navigation for location and status information.
Rail
Precise knowledge of train location is essential to prevent collisions, maintain smooth traffic flow, and minimize costly delays. Digital maps and
onboard inertial units allow fully-automated train control.
Recreation
Outdoor and exercise enthusiasts use GPS technology to stay apprised of location, heading, bearing, speed, distance, and time. In addition, they
can accurately mark and record any location and return to that precise spot.
Space
GPS technology helps track and control satellites in orbit. Future booster rockets and reusable launch vehicles will launch, orbit the earth,
return, and land, all under automatic control. Space shuttles also use GPS navigation.
Surveying
Surveyors use GPS technology for simple tasks (such as defining property lines) or for complex tasks (such as building infrastructures in urban
centers). Locating a precise point of reference used to be very time consuming. With GPS technology, two people can survey dozens of control
points in an hour. Surveying and mapping roads and rail systems can also be accomplished from mobile platforms to save time and money.
Timing
Delivering precise time to any user is one of the most important functions of GPS technology. This technology helps synchronize clocks and
events around the world. Pager companies depend on GPS satellites to synchronize the transmission of information throughout their systems.
Investment banking firms rely on this service every day to record international transactions simultaneously.
How.Accurate.Is.GPS?
GPS technology depends on the accuracy of signals that travel from
GPS satellites to a GPS receiver. You can increase accuracy by
ensuring that when you use (or at least when you turn on) your GPS
receiver, you are in an area with few or no obstacles between you
and the wide open sky. When you first turn on your GPS receiver,
stand in an open area for a few moments to allow the unit to get
a good fix on the satellites (especially if you are heading into an
obstructed area). This gives you better accuracy for a longer period
of time (about 4-6 hours).
It takes between 65 and 85 milliseconds for a signal to travel from a
GPS satellite to a GPS receiver on the surface of the earth.