An improved arctangent algorithm based on phase-locked loop for heterodyne detection system<xref rid="cpb_28_3_030701fn1" ref-type="fn">*</xref><fn id="cpb_28_3_030701fn1"><label>*</label><p>Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).</p></fn>

An improved arctangent algorithm based on phase-locked loop for heterodyne detection system**

Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).

Yan Chun-Hui^{1, 2}, Wang Ting-Feng^{1, †}, Li Yuan-Yang¹, Lv Tao^{1, 2}, Wu Shi-Song^{1, 2}

The detectable displacement of target vibration when the detection distance is 30 m. In panels (a) and (c), the bandwidth of the bandpass filer is 300–3000 Hz and 900–1100 Hz, respectively; panels (b) and (d) are the corresponding partial enlarged details of panels (a) and (c).