A Method for Improving Three-Point Ranging Accuracy under Low SNR

The commonly used cross-correlation time delay estimation method in three-point ranging does not perform well under the condition of low SNR, this article proposes an improved method for three point ranging, which try to combined generalized cross-correlation with second correlation delay estimation method and modify the time delay estimation flow path of three point ranging. Compared with the conventional three-point ranging algorithm, the new method combines the advantages of those two methods and has more steps in time delay estimation flow path. First, the three signals are pre-filtered. Next, a second correlation process is designed between the three signals to obtain two cross-correlation functions. Finally, cross-correlation is performed between the two cross-correlation functions and a final time delay is produced. With the time delay, the distance can be measured by the three-point ranging principle. Repeated simulation experiments show that the improved method has higher ranging accuracy under low SNR conditions than the traditional method.