THE METHOD OF IDENTIFYING THE TYPE OF UNMANNED OF THE AVIATION COMPLEX BY ITS RADIO SIGNALS

Abstract

The article proposes a method for determining the type of unmanned aerial complex (UAC) based on its radio signals, which is based on a comparison of the estimated parameters of the UAV radio signals with known values stored in the database. The following characteristics and parameters of the signal are proposed as recognition features: the appearance of the amplitude-frequency spectrum (AFS) and spectrogram of the radio signal; radio line frequency range; accumulated ASF width; ASF width of the frequency element; spread spectrum parameters (hop duration; rate of frequency hopping spectrum spreading (FHSS); number of FHSS frequencies; FHSS frequency grid step); modulation parameters (symbol rate; modulation index); the position of the autocorrelation function (ACF) peaks; constant symbol sequences. Peculiarities of definition and application of the indicated recognition features are analyzed. It is shown that the most informative features are modulation parameters and constant symbol sequences. In order to increase the probability of correct recognition of UAC, in addition to the indicated features, it is suggested to use the power of received radio signals and the direction of the radio emission sources. A combination of two well-known approaches was used to make a decision about the type of UAC: the decision tree method and the minimum metric method. The application of the first made it possible to reduce the computational complexity due to the exclusion of operations for radio signals parameters evaluating that do not correspond to the decisions made at the previous stages. The minimum metric method was chosen taking into account the simplicity of its implementation and ensuring the possibility of expanding the list of known UAC radio signals without significantly changing the developed recognition method. The proposed method consists of six stages, in which recognition features corresponding to the signal spectral characteristics, spread spectrum parameters, modulation parameters, constant symbol sequences, power of the received radio signal and bearing on the UAV are determined in turn. The indicated features are compared with the known ones stored in the UAC radio signal database using the minimum metric method. In case of coincidence of the estimated and known information, a decision is made about the type of UAC, and the remaining stages are not performed. Verification of the developed method was carried out by applying it to the analysis of radio signals of known UAC, in particular, “Orlan-10”, “Supercam S350”, “Lancet”, “Eleron-3SV”.