GPS Error Situations
I recently acquired a TomTom satnav and have been very impressed with the speed of satellite acquisition and position calculation. However a few weeks ago it got lost (by serveral hundred metres for several minutes). It's never done this before, but this was three times in the same place over a period of about a week. It was on the A1 and I've got a feeling it was near Ferrybridge. The only thing I could see was a high density of power lines. I suppose if they were the cause, and it was noise, then the satnav would just get lost full stop. Instead it was moving in the right direction, just with this big and fluctuating error. A factor might have been the A1 was taking a new course - that's a possibility - and it was trying to place itself on something in its memory. Anyway I just wondered if anyone else had seen situations were GPS can give erroneous positions without reporting signal loss, obviously with the perspective of how this might affect reliability in flight.