Recognition of propeller-driven aircraft in a passive bistatic radar

Nowadays passive bistatic radars (PBR) allow for detection, determination of coordinates and tracking of moving objects. In order to enable PBR integration into air traffic control systems, it is necessary to solve the problem of recognizing airborne objects, in particular, propeller-driven aircraft (AC). This will increase the degree of aviation safety. To solve the recognition problem, the analysis of propeller-driven aircraft echo signals, such as helicopter and propeller airplane, is performed. The in-formative features that can be used for recognition of propeller-driven aircraft in PBRs are defined. The method for propeller-driven aircraft recognition is proposed, that is based on extraction of modulation components originated from the rotational parts of the aircraft and estimation of their rotation parameters. The algorithm for echo signal processing is developed, which makes it possible to apply the proposed recognition method for PBRs. The experimental results of the processing algorithm are presented on the example of real signals reflected from the Mi- 8 helicopter and the Cessna 172 propeller aircraft. The experimental data are recorded by two different PBRs using DVB-T2 digital terrestrial television signals standard for airspace illumination. The estimated rotation parameters of the aircraft propeller blades correspond to the actual values. Such a correspondence allows not only to recognize the aircraft group, but in some cases to identify its type.