Two-hierarchy hough transform based track initiation method for sky-wave over-the-horizon radar

The 3L (low data sampling rate, low measurement precision and low detection probability) features of sky-wave Over-The-Horizon Radar (OTHR) pose new challenges to the conventional track initiation methods. In this paper, a Two-Hierarchy Hough Transform track initiation method (TH-HT) is proposed. Firstly the range-time data space is used to hierarchical I Hough transform and rough candidate tracks are obtained, where Doppler is used as an accumulation constraint; then such rough candidate tracks are further refined by time-azimuth accumulation in hierarchical II Hough transform. Moreover, two theorems concerning the expectation of the number of clutters voting to each cell of each hierarchy are given, which provides a way of determining the two-hierarchy threshold value. In simulation, the proposed method is compared with the classical initiation method of OTHR-MMUPDA. Simulation results show that TH-HT has higher track detection probability and lower false track probability; meanwhile it is much less time-consuming.