Radar CFAR Thresholding in Clutter and Multiple Target Situations

TLDR

Radar detection relies on comparing received signal amplitude to a threshold, with cell‑averaging being a common adaptive approach. The study aims to achieve a constant false‑alarm rate by applying an adaptive threshold that reflects the local clutter environment. The method selects a single ordered‑statistic value as the CFAR threshold, differing from rank‑statistic approaches. The ordered‑statistic CFAR outperforms cell‑averaging CFAR when multiple targets lie in the reference window or when the window crosses clutter edges.

Abstract

Radar detection procedures involve the comparison of the received signal amplitude to a threshold. In order to obtain a constant false-alarm rate (CFAR), an adaptive threshold must be applied reflecting the local clutter situation. The cell averaging approach, for example, is an adaptive procedure. A CFAR method is discussed using as the CFAR threshold one single value selected from the so-called ordered statistic (this method is fundamentally different from a rank statistic). This procedure has some advantages over cell averaging CFAR, especially in cases where more than one target is present within the reference window on which estimation of the local clutter situation is based, or where this reference window is crossing clutter edges.