A system, configured to mount on an ownship vehicle, includes a transceiver configured to receive positioning signals and receive surveillance signals including surveillance data from a second vehicle and processing circuitry configured to determine a location of the ownship vehicle based on the positioning signals received by the transceiver and determine expected characteristics of the surveillance signals based on the surveillance data. The processing circuitry is further configured to compare the expected characteristics and actual characteristics of the surveillance signals received from the second vehicle and determine that the surveillance signals include a discrepancy indicative of false positioning signals in response to comparing the expected characteristics and the actual characteristics. The processing circuitry is configured to output an alert signal indicating the false positioning signals in response to determining that the surveillance signals include a discrepancy.