How does GPS (Global Positioning System) work?

GPS (global positioning system) GPS (Global Positioning System) is a satellite navigation system developed by the United States Department of Defense and operated by the 50th space wing of the United States Air Force. With technological advances in jumps and limitations, a system was developed specifically for use by the army, which is now widely used as a GPS for accurate tracking and mapping, it was provided to citizens in the 1980s.

Worldwide, positioning on your PDA does not reflect the picture of how complex the GPS technology is. The US Department of Defense spent $ 12 billion to develop this system, which made navigation and positioning of the game for children.

It uses a constellation linking 24-32 satellites orbiting around the Earth, which transmit well-defined radio wave signals that allow GPS receivers to determine their existing location, timings and their speed.

GPS satellites The GP system uses information provided by GPS satellites orbiting around the Earth twice every 24 hours at a speed of about 7,000 miles per hour. All GPS satellites are equipped with solar panels and then use solar energy to power resources. They have backup batteries installed on board to keep up when a solar eclipse or any similar event occurs. These satellites are equipped with small rocket boosters that can be deployed when they deviate from the original path.

Satellite signals Each of these satellites currently sends signals to receivers on the ground who process all the information. Based on these calculations, you can accurately determine the position. These signals provide location, speed, and time using accurate orbital information and relative orbital distances of GPS satellites. Signal enterprises of the three main parts - pseudo-random code, ephemeris data and almanac data. The satellites transmit 2 low-frequency radio signals L1 and L2, the civil GPS uses the L1 signal, which has a frequency of 1575.42 MHz in the UHF band. These signals can then not pass through solid buildings, mountains, etc. A pseudo-random code provides information about the satellite, which is identified by a unique code. Ephemeris data provides satellite location information and other related orbital information. Almanac data are provided at regular intervals and contain valuable information about the current date and time, which is very important for determining the position of the receiver.

Trilationation The concept of GPS is based on "Trilatation" or in simple words "triangulation". Trilation is a method that uses the geometry of triangles to determine relative positions. By calculating the differences between different satellites, we can determine the location of the receiver. Magellan and Garmin offer superior GPS receivers that are exceptionally accurate due to their parallel channel design. These receivers are locked onto satellites and keep in touch even in dense forest areas or regions that are very populated and have a large number of buildings. Certain atmospheric factors also affect the accuracy of these receivers. A GPS receiver connected to 4 different satellites can accurately determine three dimensions: latitude, longitude and altitude. With a device locked to 2 satellites, there can only be a 2d view, that is, longitude and latitude. GPS requires extremely accurate clocks. The most perfect clock made before the date is the atomic clock. GPS uses the same watch on its satellites. But for the end of the receiver, setting the clock in the devices would make it inaccessible, so the developers came up with the idea of ​​using the 4th dimension in determining position. Thus, the normal position can be easily established using the signals of not four, but four satellites.

MAGELLAN AND HARMIN Leading brands with GPS solutions, Garmin and Magellan offer a variety of products.

• For portable and onboard navigators, the nuvi and zumo series of the Garmin and Magellan maestro and triton series offer exceptional coverage on and off-road for all types of vehicles. These navigation handheld computers and stationary navigators are best suited for hiking, cycling and camping around the world, wherever you are in a car or on foot.
• Both Garmin and Magellan have equally competitive products for land, air and sea navigation systems, machines for mining and agriculture, vehicle navigation and aerospace solutions. They provide professional GPS solutions for avionics and security, radar and autopilot, marine networks, sensors and circuit boards for surveys and recreational use.
• Blackberry and PDA for integrating mobile and laptop computers with GPS receivers is another line of products. Now you can use GPS in motion with the revolutionary products offered.
• Individual software solutions from Magellan and Garmin GPS-navigators for topographic, sea and street navigation. Fully detailed maps with extensive coverage points, including lakes, mountains, streets, monuments, parks and a wide range of addresses, make this world-class navigation equipment.

New and more accurate technologies are flooding the market, such as upgrading to a differentiated global positioning system (DGPS) offered by Garmin, carefully deployed by the US Coast Guard, which gives an accurate position report with a range of three to five meters. Recent Garmin GPS receivers are equipped with a WAAS (Wide Area Augmentation System) that averages 3 meters by improving and transmitting GPS signals through beacon transmitters.

Limitations and errors introduced in GPS receivers

• Delays in the atmosphere during the passage through the ionosphere and the troposphere introduce errors of the delay time in the signals.
• Incorrect synchronization and correction of the atomic clock time in the satellite and the receiver.
• Ephemeris errors - errors due to incorrect coordinates of the satellite location.
• GPS does not work underwater, underground, or inside buildings.
• It is required to clear the Facial area of ​​view from the satellite to the receiver. Any obstacle caused by buildings and dense flora leads to erroneous results.

GPS is widely used and therefore has many applications. They can be widely attributed to the military and civilian industries. Whether it is land, sea or aerial GPS, it becomes absolutely important. Surveyors, sailors and the aviation industry are highly dependent on these technological wonders. Other active clients include car clients and recreational sports. GPS unduly changed the way of life and lifted it to new heights.