Developers at Siberian Federal University (SFU) have proposed a method to increase the angular resolution of radar stations without increasing the size of the antenna system. The technology uses digital processing to form a virtual aperture that complements the real elements of a small antenna array.
The solution is based on an array of four real emitters with a weakly directional pattern. When processing signals, the system forms virtual elements located symmetrically relative to the real ones.
This allows for a larger effective aperture without a corresponding increase in physical construction.
First, the system approximately determines the direction of signal arrival by the phase difference between the real elements. Then, digital processing refines the angle using a combined real and virtual aperture.
Engineers point to the possibility of detecting signals whose level is below the receiver's own noise. At the same time, virtual elements themselves do not increase the signal-to-noise ratio – the gain is achieved by improving the angular characteristics of the system.