Posted by: gardening

Accuracy is one of the most important features of a GPS device. The GPS device tells you about the location of your car with great accuracy. Several methods have been developed over the years to improve the accuracy of GPS. Mostly GPS units are combined with a gyroscope and a speedometer. This way the computers can maintain their own navigation even when the GPS signals are blocked.

Wide Area Augmentation System (WAAS) is one such system which was developed to improve GPS accuracy. The method is not used much today due to shortage of additional satellites. GPS errors are calculated in WAAS. These errors after being calculated by the ground stations are uploaded on to additional satellites. The corrections are then transmitted to GPS receivers.

Since this system is not used much, some variants of this system are being developed in Japan and Europe. The system may be used for some critical application like GPS-based instrument landing for planes in the years to come. This system is believed to have a lot of potential for the future.

LAAS or Local Area Augmentation System is very similar to WAAS. The data in this system is transmitted from any local source. The place from which data is transmitted should require accurate positioning. It uses correctional data. Its limitation is its short range; the data being used only within 50 km of its spread.

The local FM signal sent by the Differential GPS or DGPS is used by the civilians to get the exact GPS readings. A series of fixed GPS receivers are used. DGPS can cut down a 4-20 meter GPS location to about 1-3 meters. The system calculates the difference between the real position of the receivers and the position calculated by the handsets.

Relative Kinematic Positioning or RKP can fix the range signal with great accuracy. The accuracy is of less than 10 cm. The signal is transmitted and received by the receiver in cycles and the accuracy is made possible by arriving at the number of cycles.

An accurate satellite clock and orbital data is provided to the receivers by the Wide Area GPS Enhancement or WAGE. This system enhances GPS accuracy by this method. Carrier-Phase Enhancement or CPGPS is another technique to increase GPS accuracy. It uses the 1.575 GHz L1 carrier wave. The wave acts like a clock signal and due to this the discrepancies are resolved to an astounding 10-30 cm.

These are some of the methods which have been developed in the past to improve GPS accuracy. As the technology progresses, many more methods to enhance GPS accuracy are bound to come up!