In our devices we use an off-the-shelf GPS chip set. It's very commonly used. It's the same chip set that might be used in airliners, or by the military. The specifications on that GPS chip set are that 95% of the points recorded are accurate through 10 metres. We actually see slightly greater accuracy than that on occasion.
Sometimes in an impaired environment we may see degraded accuracy. For example, in an urban canyon inside some buildings we might get a little bit of GPS and we'll see degraded accuracy. But we go ahead and transmit. We display that accuracy so that an agent who's looking at a GPS point knows the margin of error on that point.