Doppler Information Extraction of Segment Signal Using S-mvdr Method in Hfswr

This paper proposes a novel spectrum estimation algorithm in order to extract the Doppler information of segment echo data of high frequency surface wave radar (HFSWR) operating at sweep frequency mode. Working in this mode, the HFSWR can avoid interferences related to radar frequency, such as ionospheric clutter, sea clutter, and cochannel interference. However, the echo signals operating at the same frequency are segmental due to the random phase differences among echo segments. It is difficult to extract Doppler information of the specific data since the monitoring time of each segment is short. To solve this problem, this paper establishes a model of echo signal in the sweep frequency mode, and proposes an improved S-MVDR (segment-minimum variance distortionless response) algorithm according to the characteristics of the signal model. It is demonstrated by theoretical analysis that the S-MVDR algorithm can improve the resolution of the spectrum estimation without losing any frequency information. Simulations show that the S-MVDR algorithm has higher resolution and signal noise ratio than other segment signal spectrum estimation algorithms.