Analysis of recorded helicopter echo

The problem of a hovering helicopter detection and classification with a radar system is presented. First, the possible components of a helicopter echo are analyzed. A theoretical model of helicopter rotor backscatter is described, showing the anticipated detection difficulties. An experiment, consisting of radar signal recording and off-line analysis is outlined. The analysis results show the possibility to identify a helicopter echo by time- or frequency-domain characteristics. The probability of detection during normal radar operation is, however, shown to be moderate