The computer controlled frequency surveillance system utilizes a small computer in conjunction with a digital interface unit, to act as the controller between the computer and two completely programmable receivers. It operates in the frequency range from 20 Hz to 1 GHz with a programmed dynamic range of at least 120 dB. The system can, with proper programming, detect, analyze, correlate, and display all of the frequency information which the basic receivers are capable of intercepting. In addition, self-calibrating features are also included as well as the ability to make decisions based on the data received by the receiver. These decision making aspects, or branches in the program allow the frequency surveillance system to perform a multiplicity of functions, which can be predetermined. The basic concepts required in the development of a computer controlled frequency surveillance system are presented. Numerous applications are cited describing the far-reaching potentials inherent in this type of system. The functional operation of the system is discussed in relationship to the receiving systems and the computer programs.