Poor position precision with C-GPS

Legacy Open AT
1

Hi,

We have build a setup Wavecom+C-GPS+PC, and try to study Wavecom for navigational purposes. There is something VERY strange with measurements of coordinate. Position reported by Wavecom is always about 500m away from real position when we drive a car. We basically user slightly modified version of QuerryApp. (We read NMEA string and convert it to get coordinates)

We are probably doing something wrong. Any hints where to look? Also could someone please comment on their precision measurements.

Alexander

2

Hi Alexander, can yo be more specific on your GPS precision problem? If it´s always in the same direction (related to earth or related to your movement), maybe you have a mistake in your conversion code. Perhaps you have a timing problems and your position reports are those you left behind when moving on your car… I´m working on a NMEA GPS device right now (not c-gps, just an oem module), and i had some troubles with that in my application. I hope my answer is understandable, mi english isn´t very good.