Determination of the pulse repetition interval (PRI) agility of an incoming radar emitter signal using instantaneous power analysis

Determining the level of pulse repetition interval (PRI) agility is important in the field of Electronic Intelligence (ELINT) in order to provide warning receiver and jammers with the appropriate information in order to take action. This paper uses smoothed instantaneous power in order to estimate the PRIs of an incoming radar emitter signal. The test signals considered for this work is made up of simple pulsed and staggered PRI radar signal of various intervals and position. The algorithm designed uses the Hilbert transform to obtain the analytic version of the incoming signal before the Hamming smoothed instantaneous power is applied to the signal. Thereafter, first, second and third PRI are obtained and used to form rules for the rule-based Classifier. The rule-based classifier classifies the signals in order to determine the level of PRI agility. Performance analysis is carried out in the presence of additive white Gaussian noise (AWGN) for 100 iterations. Results obtained showed that a 100 percent probability of correct classification is obtained at signal-to-noise ratio (SNR) equal or greater than 3dB irrespective of the incoming signal.