为了提高罗兰C系统测量精度，利用罗兰C信号收发已知的特点，提出时频域相结合构造代价函数寻优的方法对天波时延与幅度进行估计。首先讨论了时域、频域代价函数的估计性能。通过讨论得出在时域构造代价函数对幅度分辨率较高，在频域构造代价函数对时延分辨率较高的结论。而后根据所得结果，提出在时域构造代价函数估计天波幅度，在频域构造代价函数估计天波时延，并利用迭代提高估计精度。通过计算机仿真，验证了算法的有效性。

To improve the precision of Loran-C, a novel signal processing technique was presented using the cost function constructed by using time/frequency domain for estimating skywave fade and delay in Loran-C receiver, which was based on known waveform and period of Loran-C signal. Firstly, the performance of cost functions for time and frequency domain was discussed. The result was that time cost function could estimate the fade precisely and frequency cost function could estimate the time delay precisely. Based on the results, time cost function was used to estimate skywave fade and frequency cost function was used to estimate skywave delay, and iterating was used to improve the precision. Simulation results proved its effectiveness.