PSAsidelobes

PSidelobes refers to the unwanted secondary peaks in the output of a pulse compression system, particularly in radar and sonar applications. When a pulse is compressed, its duration is shortened, and its bandwidth is increased, leading to a higher resolution. However, this process can also generate sidelobes, which are small amplitude signals that appear before and after the main compressed pulse. These sidelobes can be problematic as they may be misinterpreted as actual targets, or they can obscure weaker targets that are close to stronger ones.

The generation of PSidelobes is a consequence of the mathematical operations involved in pulse compression, such as matched filtering. The shape and amplitude of these sidelobes are dependent on the characteristics of the transmitted pulse, such as its waveform and bandwidth. For instance, a linear frequency modulated (LFM) pulse, also known as a chirp, is commonly used for pulse compression. While effective, LFM pulses inherently produce PSidelobes that decay relatively slowly.

Various techniques are employed to mitigate the impact of PSidelobes. These include amplitude weighting or tapering of the transmitted pulse, which reduces the amplitude of the sidelobes at the expense of a slight broadening of the main lobe and a reduction in the peak amplitude of the main lobe. Another method is the use of non-linear frequency modulation (NLFM) waveforms, which are designed to have lower sidelobes without significantly sacrificing range resolution. Advanced signal processing techniques can also be used to suppress PSidelobes after the pulse compression has occurred.