i need more details about the circuit and working of vehicle mileage tester

Method of monitoring vehicular mileage

In this system, A navigational system and a computer-based datalogger are used to store data on the distances traveled by and places visited by a monitored vehicle.The apparatus relates to data processing systems employing a satellite navigation system, such as the Global Positioning System (GPS) for tracking places traveled to and distances traveled between the selected points. The system here has the facility for recording the distances traveled and the places visited by a monitored vehicle equipped with a navigational receiver and a computer-based datalogger having a clock and an on-board memory so that the datalogger can store records of the latitude and longitude of places visited by the vehicle along with their time-stamps. The driver is provided an input means by which he or she can assign a label or way point identifier to each one of the destination visited or an administrator can use a central computer located at the vehicle's home base to assign labels to predetermined locations. The set of time-stamped records from the vehicle are sent to the central computer and at the same time communicating administrative information from central computer to the on-board datalogger. a map-like graphical output display is generated using the software and also also displays the time spent at each destination. the central computer calculates the distance between destinations visited for business purposes and between any one of the destinations visited for business purposes and the home base, and identifies these as trips of a first type.time spent at unlabeled destinations, labeled destinations, time spent at non-business purpose places etc are monitored by the system. The total distance traveled by the vehicle is measured and sent to a central administrator responsible for distance-based scheduled maintenance of the vehicle and also average speed of the vehicle during a monitored interval. Using this the vehicular mileage is determined.
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