Why is civilian gps less accurate

According to the Pentagon, military GPS receivers are accurate to within about 20 metres, even without this refinement, known as differential GPS. However, Stan Huntting, the author of a program called SA Watch, which estimates the error in the GPS signals, says that on 20 April civilian GPS receivers were providing locations with an accuracy of as little as 2 metres without the help of rebroadcasting.

But Don Miles, a lieutenant-colonel and spokesman for the space command, refuses to say why. One strong possibility, however, is that the satellites were being used to aid the search for an A ground attack aircraft that disappeared during a training exercise in Arizona earlier in the month. Both civilian and military planes were scouring a mountainous region of Colorado for wreckage, and giving all of the aircraft involved access to the same high-quality satellite navigation signal would have helped speed the search.

To be clear, URE is not user accuracy. The ongoing GPS modernization program will further improve accuracy for civilian and military users. Learn more. The government distributes UTC as maintained by the U. This performance standard assumes the use of a specialized time transfer receiver at a fixed location.

However, most of today's civilian devices use only one GPS frequency, while military receivers use two. Using two GPS frequencies improves accuracy by correcting signal distortions caused by Earth's atmosphere. Dual-frequency GPS equipment is commercially available for civilian use, but its cost and size has limited it to professional applications.

With augmentation systems, civilian users can actually receive better GPS accuracy than the military. During the s, GPS employed a feature called Selective Availability that intentionally degraded civilian accuracy on a global basis. The United States has no intent to ever use Selective Availability again. Get software. GPS is operated and maintained by the U. If your line of work requires GPS navigation and a GPS signal generator —whether it is for military or civilian use—feel free to call us about it today.

Catching Up to Military GPS Equipment The military uses dual-frequency equipment to avoid signal distortions that could jeopardize their mission or research. They are available for differential, static, and real-time techniques. September 1,