Techniques are provided which may be implemented using various methods and/or apparatuses in a vehicle to determine proximate vehicles, for example, vehicles within a pre-designated range or within broadcast distance or otherwise geographically proximate, through the use of broadcast or other messages sent by the other vehicles, and to obtain GNSS carrier phase measurement data from the proximate vehicles wherein the shared carrier GNSS phase measurement data may be utilized to update the location(s) of proximate vehicles.