Essay on Global Positioning System

GPS System Report

Introduction

Global Positioning System abbreviated as (GPS) is a cluster of nearly 30 well-spaced Satellites that orbit the Earth and enable individuals with ground receivers to identify or locate their geographic place. In most GPS equipment, their place accuracy is within the range of 100 to 10 meters.

Long before improvement on internet, during unfavorable conditions or when catastrophes stroke, people would be engulfed by saddening news on missing boats, ships, airplanes and misplacement of Army convoys. This would send people into a sea of stress as well as waste their time trying to locate the address manually. However, with improved technology, GPS can now provide easy guides to track the world. It has enabled scientists to explore the world without fear of getting lost.

2.0 Global Positioning System Basics2.1 Global Positioning System ComponentsAccording to Global Positioning Systems (GPS) for Pilots, the GPS system is made up of three main components: the space segment, user segment, and the control segment. The space element comprises of approximately 31 GPS satellites. The United State Air Force uses the 31 satellites and four decommissioned ones. The decommissioned satellites can be reactivated if need be. The ability of satellites to cover an area completely makes the GPS be the most dependable and secure navigation system in the contemporary aviation.

The user segment consists of sundry receivers from various types of industries. The end users in the GPS system includes the national intelligent, survey, agriculture, space and the mapping sectors. Finally, the control segment consists of a chain of ground stations that interpret and convey satellite signals to diverse receivers. These ground stations include the 12 ground antennas and master control station.

2.2 Global Positioning System Accuracy FactorsThe accuracy of a GPS system is approximated to 15m. This accuracy is subject to several factors including the delays in the atmosphere, multipath signals, errors due to orbit and satellite clock as well as the geometry of satellite relative to the GPS user. As satellites move in their paths (orbits), obstructions from the atmosphere lead to blockage of some signals thus making the geometry of the satellite signals limited to the user keep changing CITATION Jon15 \l 1033 (Jonathan Vail, Mel Parsons, Brian Striggow, John Detrick, Hunter Johnson). Global Positioning Systems3.0 How Global Positioning System WorksGPS satellites orbits about 19,300kms from the earth surface and takes exactly twelve hours to complete one orbit. GPS are powered by solar and transmit the signals to the receivers on the ground stations. The satellites orbits are arranged in such a manner that at any given time, there are at least four visible satellites in the sky. The work of the receivers is to locate at least four satellites, calculate the distance to each satellite and use the information to come up with its own location based on a mathematical principle known as trilateration.

4.0 Global Positioning System ErrorsAlthough GPS is the most reliable provider of person's location, altitude, and speed, it has some internal error sources that require receivers to take care of when reading the system signals from the satellites. The main source of error in GPS is poor time keeping the receiver's clock. This error is commonly known as clock error. Receiver's inbuilt computers use radio signals that travel at a speed of light from at least four satellites to deduce its location, speed, and the altitude. The discrepancies between the receivers and the GPS clock cause the drift in the calculated distance CITATION Mio16 \l 1033 (Global).

Also, there is another error referred to as orbital error. In this case, the movement of the satellites along the orbits may be inaccurate which may result in ambiguity when determining the location of the satellite.

However, the discrepancies can be corrected in two ways: the first way is through the use of atomic clocks in the receiver. But this might be a bit expensive since each atomic clock costs over $100,000. The second and mostly used solution is the employment of some mathematical tricks to account for the errors depending on how the microwave radio signals are received from the four or more satellites which allow the receiver to reset its clock to fit the accurate location. This method is widely used by the majority of navigations device manufacturers since it is cost effective compared to the former CITATION Mio16 \l 1033 (Global).

Other errors from GPS may arise from obstruction of signals by the atmospheric disturbances. This may slow the signals before they reach the receiver. Also, large solid objects, as well as buildings, may interfere with the GPS accuracy through the reflections that alter the signals. This error is known as position error.

5.0 Use of Global Positioning System

The GPS systems are very versatile and are used in almost all industries. They are used in determining positions as well as in geospatial sector for creating world maps (Zhong, Maiying, Jia Guo & Donghua Zhou). Moreover, pilots used GPS systems every day while flying with airplanes. GPS are also used in navigation where the ship captains use them to determine the position they are sailing to. Lastly and most important is the use of bringing precise timing to the world. In conclusion, GPS has positively impacted the way we operate, and it forms the most important part of the technology that helps people navigate the world with no fear of getting lost.

Works Cited BIBLIOGRAPHY Global, Mio. GPS accuracy and error sources. 23 May 2016. <http://www.mio.com/technology-gps-accuracy.htm>.

Jonathan Vail, Mel Parsons, Brian Striggow, John Detrick, Hunter Johnson. Global Positioning System. Washington, 2015.

Zhong, Maiying, Jia Guo & Donghua Zhou. ""Adaptive in Flight alignment of INS/GPS systems for aerial mapping"." IEEE Transactions on Aerospace and Electronic System (2017).