How Do GPS Based Vehicle Tracking Systems Deal With Error In GPS Positions?

How do GPS based vehicle tracking systems deal with error in GPS positions?

Meta description: Several reputed fleet companies implemented the GPS tracking system in the business. But how will a GPS vehicle tracking system overcome errors. Lets check it out...

As a matter of fact, considerable changes have been introduced in the GPS based vehicle tracking systems over the past few years. Though new models of GPS vehicle tracking systems soon increased accuracy and precision, the GPS trackers sometimes fail in the task. Researchers therefore is focused further on the development of error-free and cost effective models, which can transmit the data as accurately as possible and henceforth it can be analysed by the fleet management software.
Meanwhile, the system utilizes ground reference stations and their coordinates to increase the accuracy. Nevertheless, the system is slightly expensive and serves those purposes, which require high accuracy.

Precision also reduces when the satellites are widely apart or clustered together. For highly precise location, one satellite should be directly above the vehicle, and the other three should be spaced equally and stationed as close to the horizon as possible. However, the error is predictable and can determine the quality of the GPS data. When analysing data for fleet management purposes, the data quality is first ensured.

2. Clock errors
Normally, the location and distance covered by the vehicle is calculated from the difference in the time, in which the signal is sent and then received back. Therefore, any error in the GPS clock might get translated to error and decrease accuracy. Satellites normally carry three or four Atomic clocks, which are in turn used by the local atomic clocks to synchronise and correct to the UTC (Coordinated Universal Time). These local clocks in turn are utilized to correct the GPS devices and
Predictive Analysis techniques are being implemented to model the ionosphere and to calculate the corrections. GPS reference stations on the ground can transmit these corrections to the satellites and they can transmit the data along with the corrections to the GPS receiver. Fleet management solutions can in turn incorporate the data as well as the corrections thus provided to eliminate such errors.

b. Error due to other atmospheric layers

The other atmospheric layers beneath the ionosphere, such as stratosphere, troposphere etc. also cause inordinate delays in reaching the earth’s surface. And, the delay might be significant for signals from far satellites, but whose quality is more reliable. Such delays can also be predicted and used to adjust the error in the GPS data.

3. Satellite factors

Satellite parameters such as orbital path, velocity, etc. vary even though in a minor range. For an accurate vehicle location identification, the exact position of the satellite in the orbit and the velocity need to be taken into account. The control unit monitor these locations, and any orbit anomalies are calculated and collectively send in batches known as ephemerides. Simply, it is like the satellite identifying its own position relative to earth and sending it in batches to the GPS receiver on earth so that the distance errors can be minimised. Advanced versions of GPS vehicle tracking systems can compute the error and correct it