Improved DOA estimator for wideband sources using two references

The source line fitting method (SLFM) is effective for estimating DOAs of wideband signals, when the inter-element spacing of the array exceeds half the wavelength. It exploits one reference to construct source lines (SL), and estimates DOAs by measuring the angles of SLs. In this paper, we improve SLFM by using two reference signals, which is called two references SLFM (TRSLFM). The incremental reference makes the proposed method estimate DOAs with more information. Simulation shows that TRSLFM performs better than SLFM in the whole SNR ranges, and needs fewer sensors to achieve the same accuracy.