Definition and Description Essay Example | Topics and Well Written Essays - 1000 words

Definition and Description - Essay Example This paper provides a detailed technical description regarding this gadget, alongwith visual illustrations, to help layman understand how it actually works. (http://asset2.cbsistatic.com/cnwk.1d/sc/32934833-2-300-SS16.jpg) External Dynamics Modern GPS devices installed have wide variety of features and fancy designs matching car interiors. With sleek and stylish dimensions, these systems add to the overall functionality and suavity of trendy vehicles. Normally, this navigation system uses multiple satellites spread across the sky and calculates variables from different points of references to estimate as close as possible the position of user. This is illustrated by diagram given below. This system is based on one-way time of arrival ranging phenomenon, whereby high atomic frequency signals are sent by satellites to synchronize with GPS time base. It is pivotal that the receiver and satellite both have powerful atomic clocks with synchronization capabilities up to nanoseconds. These electromagnetic radio waves have a traveling speed equivalent to speed of light, traveling at frequencies of L1 C/A and L2 P/Y and rate of 50 bits per second. Thus, time taken for one cycle of transmission and processing of one complete message is only 750 seconds. Signals are encoded through CDMA technology (Code Division Multiple Access) so that GPS deciphers the information and identifies one satellite from another due to unique encoding techniques. However, it is of utmost importance that vehicle has a clear view of the sky with no obstructions blocking the satellite transmissions. The functionality of GPS relies on three sectors. Space segment comprises the entire satellite orbital system being funded and managed by spatial authorities. Second segment is represented by control segment which carries out maintenance and monitoring of functionality of entire global positioning system through master control stations. Last segment is the user segment, which constitutes the usage of GPS system in consumer applications, military instruments and various day-to-day commonly used devices. (Kohli & Chen, 2000) Internal Mechanism GPS is based on a basic mathematical principle of trilateration: GPS must have information regarding location from three different satellite points and the distance of these satellites from current location. There are mainly three broad categories or components that form a car GPS mechanism. Inside the GPS, there is an inbuilt antenna receiver which receives the radio signals sent by satellites which contain information about timing to enable the GPS to compute the position as accurate as possible. The transmitted information has multiple sub-frames. The first sub-frame encodes time-based information like week number, day and time as well as information indicating the satellite’s health and signal strength. The second and third sub-frames feed data about the precise orbit of satellite. The fourth and fifth sub-frames carry status info rmation of the entire satellites network. The antenna demodulates the message to extract maximum accurate information from these frames and identifies each satellite through designated exclusive binary codes for each. The decoded information is transferred to the next division then for processing (Bajaj et al, 92-94). The cycle begins when the satellite and receiver simultaneously