No abstract

In this article, a constant false alarm rate (CFAR) detection algorithm based on the fractional Fourier transform (FRFT) and orthogonal projection (OP) is proposed. With a low signal‐to‐clutter ratio (SCR), the radar returns of sea‐surface small targets are often submerged by sea clutter. The FRFT can accumulate target energy in the optimal order. Meanwhile, the OP suppresses the sea clutter in a projection space in the FRFT domain, thus enhancing the output SCR. The FRFT and the OP are in conjunction with the CFAR to realise target detection, which is referred to as the FRFT‐OP‐CFAR. For the FRFT‐OP‐CFAR detector, the most important is the selection of the optimal order p $p$ and the calculation of the OP operator ψx⊥ ${\boldsymbol{\psi }}_{x}^{\perp }$. The experimental results show that the proposed FRFT‐OP‐CFAR has a better clutter suppression and detection performance than some detectors in the authors’ comparison.