a radio antenna configured to receive electromagnetic radiation; and

a radio receiver including the radio antenna and a computer processor with an associated memory storage comprising instructions that when executed by the computer processor implement steps of:

receiving, by the radio antenna, multiple frequencies of electromagnetic radiation emitted from a first vehicle at a test range and measuring the multiple frequencies of the electromagnetic radiation emitted from the first vehicle;

determining, from the multiple measured frequencies of the electromagnetic radiation, one or more identifying electromagnetic radiation characteristics of the first vehicle including one or more modulation frequencies of one or more electromagnetic carrier frequencies, detected at a test range power level;

detecting the one or more identifying electromagnetic radiation characteristics in electromagnetic radiation received by the radio antenna and emitted by a second vehicle at a detection range, wherein the radio receiver is configured to detect the second vehicle electromagnetic radiation at a diminished power level reduced from the test range power level by a factor proportional to the ratio of the test range to the detection range; and

responsively issuing an alert to a defense system.