A Nonlinear Clutter Map Detector for Rockfall Detection under Moving Debris and Dust Clutter

The rockfall detection requires the Doppler radar to detect falling rocks amidst strong and heterogeneous ground clutter. Clutter map detectors are employed to provide robust detection in such scenario. In addition to ground clutter, falling rock causes moving debris and dust clutter, whose intensity has abrupt changes and causes false alarms. This paper proposes a nonlinear clutter map detector to handle such clutter. Employing a nonlinear transform of the echo power, this detector generates a maximum and a minimum sequence which characterize the intensity of abrupt clutter and stable clutter, respectively. It provides stable performance in slow-changing ground clutter and abrupt moving debris and dust clutter. Field data shows that the proposed nonlinear iterative clutter map can reduce 76.2% of false alarms caused by debris dust clutter, without affecting the detection of falling rocks.