Using the Global Positioning System (GPS), every point on Earth can be given its own unique address—its latitude, longitude, and height. The U.S. Department of Defense developed GPS satellites as a strategic system in 1978. But now, anyone can gather data from them. For instance, many new cars have a GPS receiver built into them. These receivers help drivers know exactly where they are, and can help them from getting lost.
GPS is a constellation of satellites that orbit approximately 11,000 miles above the Earth and transmit radio wave signals to receivers across the planet. By determining the time that it takes for a GPS satellite signal to reach your receiver, you can calculate your distance to the satellite and figure out your exact location on the Earth. Sound easy? In fact it is a very complicated process. For the GPS system to work, you need to have incredibly precise clocks on the satellites and receivers, and you must be able to access and interpret the signals from several orbiting satellites simultaneously. Fortunately, the receivers take care of all the calculations.
Let's tackle the distance calculation first. GPS satellites have very precise clocks that tell time to within 40 nanoseconds or 40 billionths (0.000000040) of a second. There are also clocks in the GPS receivers. Radio wave signals from the satellites travel at 186,000 miles per second. To find the distance from a satellite to a receiver, use the following equation: (186,000 mi/sec) x (signal travel time in seconds) = Distance of the satellite to the receiver in miles.
Think of it this way: When construction workers begin to build, they have to be sure that the area where they are building is free from dangerous power lines. The construction team will have to find out where the power lines are and make sure they are not building on top of them. To ensure success, the team needs to know the coordinates of the building site and of the local power lines. The National Spatial Reference System (NSRS) provides a framework for identifying these coordinates. The team can then compare the two sets of coordinates and make sure they do not overlap.
The NSRS includes traditionally placed markers, or permanent monuments, where the coordinates have been determined. Many of these markers are brass or bronze disks (metals that sustain weathering) and are set in concrete or bedrock. Most markers are about 9 centimeters wide and have information about NGS printed on their surfaces. Others are made from long steel rods, driven to refusal (pushed into the ground until they won't go any farther.). The top of each rod is then covered with a metal plate. This method ensures that the mark won't move and that people can't destroy or remove it.
With the advent of the Global Positioning System (GPS), positioning these markers became much faster and easier than traditional methods. Positioning these marks ties them to a specific horizontal or vertical datum, and then the mark helps define the NSRS. The positioning data about the marks is collected by surveyors with very accurate GPS receivers and is then loaded into the NGS database. Once the coordinates of the mark are entered into this database, they are available for anyone to use, and makes the NSRS available to everyone.
The Global Positioning System (GPS) is a space-based radio-navigation system consisting of a constellation of satellites broadcasting navigation signals and a network of ground stations and satellite control stations used for monitoring and control.
A GPS receiver determines its own location by measuring the time it takes for a signal to arrive at its location from at least four satellites. Because radio waves travel at a constant speed, the receiver can use the time measurements to calculate its distance from each satellite.
GPS does not require any form of internet connectivity. As already mentioned, GPS dependent on the signals from satellites. Anyone can harness these signals using a GPS receiver. You can test this fact by turning of the internet connection on your phone and try to use google maps.
Today, GPS is a multi-use, space-based radio-navigation system owned by the US Government and operated by the United States Air Force to meet national defense, homeland security, civil, commercial, and scientific needs.
GPS is a system of 30+ navigation satellites circling Earth. We know where they are because they constantly send out signals. A GPS receiver in your phone listens for these signals. Once the receiver calculates its distance from four or more GPS satellites, it can figure out where you are.
The general name for these systems is Global Navigation Satellite System (GNSS), but for simplicity, we will refer to GPS here as each functions similarly. GPS fundamentally consists of three components: satellites, ground stations, and receivers.
For example, GPS-enabled smartphones are typically accurate to within a 4.9 m (16 ft.)radius under open sky (view source at ION.org). However, their accuracy worsens near buildings, bridges, and trees.
GPS technology is now in everything from cell phones and wristwatches to bulldozers, shipping containers, and ATM's. GPS boosts productivity across a wide swath of the economy, to include farming, construction, mining, surveying, package delivery, and logistical supply chain management.
GPS is a system of 30+ navigation satellites orbiting the Earth. We know their location precisely because they invariably send out signals. The GPS receiver in your phone receives these signals. Once the receiver calculates its distance from four or more GPS satellites, it can figure out exactly where you are.
Satellites are continually broadcasting their orbital position and exact time at that position on radio frequencies. That signal is received by antennas, along with at least three other satellite signals, then processed in a GPS receiver to compute a user's location.
A-GPS is faster in finding the location but GPS gives a more precise location information. While there is no additional cost involved in using GPS devices, an A-GPS has additional cost involved because it uses services and resources of the wireless carrier's mobile network.
How GPS Tracking Works. The GPS tracking device is installed into a vehicle (or piece of equipment or asset) to gather real-time information including speed, idle time, diagnostics, etc. It uses Global Positioning Systems (GPS satellites) to know the vehicle or equipment's location on Earth at all times.
A GPS receiver does not transmit any signals, all it does is receive GPS data beamed to earth from GPS satellites. If you can't receive the GPS signals, you can't get your position. Each GPS unit, regardless of size, has a small chipset and GPS antenna.
Yes, GPS works because it is completely independent of any WiFi or Cellular data connection. A GPS is just a radio that receives location data from satellites, so its radio is separate from any WiFi, Cellular, or Bluetooth radio. Pre-loaded maps need no internet connection to work.
In normal operation, there is a ground station that monitors the signals from each satellite. The ground station knows where its antenna is, so it can calculate exactly where the satellite is with respect to the earth and upload new ephemeris (precise position) data to the satellite.
Introduction: My name is Msgr. Refugio Daniel, I am a fine, precious, encouraging, calm, glamorous, vivacious, friendly person who loves writing and wants to share my knowledge and understanding with you.
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