So far , there has been plenty of theory and method serving for doa . among them , one method has been paid much attention for worldwide researchers who have spent more than 30 years to develop and perfect it . this is the namable " time delay estimation ( tde ) " 而在这些众多的方位估计方法中，有一种方法让世界范围的科研工作者为之关注并已花费了三十余年的时间去不断地发展和完善它，这就是著名的“时延估计法( timedelayestimation ) ” 。
