Abstract
This paper presents a wide dynamic range data acquisition system applying in an instrument for subsurface imaging by using transient electromagnetic pulse. The objective of this system is to solve the problem of the signal dynamic range in the instrument. The basic unit in this system consists of a complex programmable logic device (CPLD) which controls the timing and waveform of the transmitted pulse, a gain programmable amplifier which is appropriate to improve the data collection accuracy and enlarge the dynamic range of the signal, and the signal interaction between the transmitter and receiver which ensures the capability of real-time. This system has good performance of real time and scalable to satisfy the dynamic range requirements.
