针对沥青面层不同材料层的探地雷达(GPR)反射信号相互叠加，降低了沥青面层厚度测量精度的问题，本文利用WRELAX时延估计算法分析沥青路面的1 GHz空耦GPR反射信号，以提高沥青路面分层厚度检测精度，并利用仿真实验和现场检测进行了效果验证。研究结果表明,WRELAX算法通过强信号搜索并在迭代计算中逐步去除强信号，使微弱的重叠信号得以显现，从而可以提取出信号时延和幅度的参数信息。1 GHz雷达信号应用WRELAX算法处理后可以有效检测沥青路面面层分层厚度，而且估计误差波动相对较小，算法稳健性较好，总体效果优于2 GHz雷达。WRELAX算法的沥青面层分层厚度估计最大相对误差小于5%，满足沥青路面分层厚度检测和评价要求。

Concerning the overlap of ground penetrating radar (GPR) signal reflections at the different asphalt layers, which reduces the measurement accuracy of asphalt surface thickness, the WRELAX algorithm for time-delay estimation was applied to analyze the air-launched GPR signal reflections with 1GHz center frequency to improve the detection accuracy of thin layers of asphalt pavement in this paper. The results were verified by simulation experiment and field test. The research results show that the WRELAX algorithm detects iteratively strong reflections and then subtracted from the original signal to reveal the weak reflections. Time-delay and amplitude can be calculated by the WRELAX algorithm. The WRELAX algorithm in 1GHz GPR signal processing can effectively detect thin layers of asphalt pavement, and variation ranges of estimation errors are relatively small. The algorithm is robust and its effect is better than 2GHz GPR signal processing. The maximum relative estimation error of thin layer estimated by the WRELAX algorithm is less than 5%, which meets the requirements for detection and evaluation of asphalt thin layers.