Techniques are discussed herein for detecting anomalous signals such as spoofed satellite positioning system (SPS) signals and for the transmission of accurate location estimates between user equipments (UEs) when the SPS signals are not reliable. A UE determines an SPS derived location estimate and determines an associated confidence level. The confidence level is determined based on time or location derived from the SPS signals, e.g., relative to local time or non-SPS information, such as stored previous location estimates, non-SPS sensor information, and location information from other UEs. The UE transmits location information to other UEs that includes a selected location estimate, confidence level, and the source of the location estimate, e.g., where the SPS derived location estimate is selected if the confidence level is high and the non-SPS derived location estimate is selected if the confidence level is low.