On account of existing problems in rock elastic wave velocity inspecting

such as low signal to noise ratio(SNR)

difficulty in reading the prime time of echo and inspecting large volume rock

pulse compression method is proposed. Linear frequency modulation (LFM) signal is mostly used as exciting source due to its remarkable properties

such as wide bandwidth

high energy and high SNR. While receiving terminal

echo signal is filtered by a matched filter

and the compression signal of high SNR is obtained. The wide time and band characteristics of LFM signal are introduced. In addition

the pulse compression principle and digital implementation process are also analyzed. The influence of the bandwidth of transducer on exciting signal is studied; elastic wave velocity of several rocks is inspected with a conventional method and pulse compression method. The wave velocity differences of two testing methods show a limited error. The detailed implementation and calculating process of pulse compression inspecting method are also described. The advantages and prospects of the method are analyzed. Results show that pulse compression method can be applied to inspect the elastic wave velocity in rock and access engineering quality.