Abstract: Time delay estimation (TDE) plays an important role in many engineering applications. In this paper a quadratic weighting of the frequency domain adaptive time delay estimation method is put forward. The quadratic weighting of the frequency domain SCOT and ML adaptive TDE algorithms are presented, respectively. The variance of the quadratic weighting of the frequency domain SCOT adaptive algorithm is derived. The algorithms are applied in the TDE of helicopter passive acoustic location. The simulation results show that the proposed algorithm has better performance in the low signal to noise ratio.