Detecting gnss spoofing signals

A processor-implemented method for determining the count of global navigation satellite spoofing signals, comprising:

• operating a plurality of antennas in a shared frequency band;
• for each of the plurality of antennas, calculating a respective feature set based at least in part on a radio frequency signal received by the antenna, and aggregating the respective feature sets to produce an initial feature set;
• applying a first machine learning model to the initial feature set to produce a feature vector representing extracted signal characteristics;
• and
• applying a second machine learning model to the feature vector, the second machine learning model being trained to classify and count navigation satellite spoofing signals, thereby determining a count of navigation satellite spoofing signals present in the shared frequency band.

A processor-implemented method for determining the presence of a global navigation satellite spoofing signal, comprising:

• operating a plurality of two or more antennas in a shared frequency band;
• computing a 2-subset collection of the plurality of three or more antennas, wherein each 2-element subset comprises a first antenna and a second antenna;
• for each 2-element subset and each of a plurality of pseudo-random codes pertaining to a plurality of satellites, calculating a code phase difference value between a phase-adjusted correlation of the pseudo-random code with an intermediate frequency signal converted from a radio frequency signal received by a first antenna in a 2-element subset and a phase-adjusted correlation of the pseudo-random code with an intermediate frequency signal converted from a radio frequency signal received by a second antenna in the 2-element subset;
• for each 2-element subset, determining clusters of code phase difference values, wherein a difference between at least two code phase differences in a same cluster is below a predetermined threshold;
• determining a first count, comprising a count of 2-element subsets for which the clusters of code phase values comprise a total of at least a predetermined number of code phase difference values;
• determining a second count, comprising a total count of 2-element subsets;
• and
• computing a probability value of a global navigation satellite spoofing signal present in the shared frequency band based at least in part on the first count and the second count.