I've been waiting over 10 years for people to finally admit to the weaknesses of GPS.
And the accuracies quoted are PR accuracies.
Real world, I have seen open field accuracies for GPS be closer to within 200 yards with brand new 2012 equipment. Or most of a football field.
In urban areas like Boston and NYC I have seen GPS fail completely. The funniest/saddest example of this was the multi-million dollar GPS tracking system installed by NYC to track everything from its fire and police vehicles to garbage trucks and plows. Quite often the vehicles display at the tracking center as being in the East River as that seems to be a default location for the system to place the vehicles when the GPS signals are lost.
It does not help that now we have 4G communications that effectively jams GPS in local areas close to 4G equipped towers.
http://arstechnica.com/tech-policy/2011/12/testing-shows-proposed-4g-network-interferes-with-75-of-gps-devices/
The GPS units most effected were the so called high precision units that claim greater accuracy.
If your current older GPS unit suffers from too many dead spots you may want to consider a newer model that has improved filtering to eliminate the 4G static the GPS picks up.
http://news.cnet.com/8301-30686_3-20109559-266/lightsquared-solves-gps-interference-with-new-device/#!
Spanish researchers say they have developed a navigation system which could improve the accuracy of GPS by 90 percent.
The future of driverless cars may look brighter if the claims ring true, made by a team based at Madrid’s Universidad Carlos III (UC3M). By combining conventional GPS signals with other sensors — including accelerometers and gyroscopes — a prototype has been able to reduce the margin of error when it comes to relaying or tracking location.
“We have managed to improve the determination of a vehicle’s position in critical cases by between 50 and 90 percent, depending on the degree of the signals’ degradation and the time that is affecting the degradation on the GPS receiver,” said David Martín, a researcher at the Systems Intelligence Laboratory.
The margin of error for a commercial GPS system is roughly 15 meters in an open field. However, due to bouncing signals and satellite interference in congested urban areas, this margin can increase by 50 meters. Instead, the new system uses contextual data and a low cost Inertial Measurement Unit (IMU) to try and fill in the gaps and eliminate issues caused by the loss of satellite signals.
Enrique Martí, of UC3M’s GIAA explained in a statement:
“This software is based on an architecture that uses context information and a powerful algorithm (called Unscented Kalman Filter) that eliminates the instantaneous deviations caused by the degradation of the signals received by the GPS receiver or the total or partial loss of the satellites.”
The researchers have created a prototype which can be installed on any standard vehicle. By using infrared, optical cameras and laser technology to gather information on the road, the team also hopes to allow a smart car to detect pedestrians and obstacles — as well as adapt speed levels in relation to traffic signals or even a driver’s weariness in real time.
Ultimately, the team hopes that this technology could be developed to take advantage of the sensors built into smartphones, such as accelerometers, a gyroscope, a magnetometer, GPS and cameras, as well as Wi-Fi, Bluetooth or GSM communications.
“We are now starting to work on the integration of this data fusion system into a mobile telephone,” commented Martí, “so that it can integrate all of the measurements that come from its sensors in order to obtain the same result that we have now, but at an even much lower cost, since it is something that almost everyone can carry around in his pocket.”
Image credit: Jamie McCall
Related:
