Study on the shallow underground imaging by the pulse compression method that considered frequency dependent attenuation

Frequency dependent attenuation of chirp wave in shallow underground is measured at each frequencies and half width (axial resolution) is calculated by simulation using measurement data. And an exploration experiment is carried out to confirm the effect of the compensation of high frequency domain. From the simulation results, half width are smaller than 0.2m are obtained when Δf is more than 500Hz (800–300Hz linear down chirp, duration time 100ms). From the experimental results, compensation of high frequency domain are effective for high resolution underground image. And linear down chirp showed the best underground image in this case. And the axial resolution of underground image is the quite same as simulation.