High-precision time-sequence control circuit of ground penetrating radar

Abstract

The invention discloses a high-precision time-sequence control circuit of a ground penetrating radar. The circuit comprises an SPI interface and a scanning unit, wherein the SPI interface is communicated with an upper computer; the scanning unit scans data obtained by the SPI interface, transmission pulses transmitted by the scanning unit synchronize with a main clock in a trigger pulse synchronization unit and then are directly output outwards, and receiving pulses transmitted by the scanning unit synchronize with the main clock in the trigger pulse synchronization unit and then are output outwards through a delay circuit. According to the high-precision time-sequence control circuit of the ground penetrating radar, parameter setting can be carried out through the SPI interface, and parameter adjustment is flexible; a delayed chip with a fine adjustment function is used, and 1ps precision delay can be achieved to the minimum; time jitter errors are reduced due to synchronization design, and stability of the time-sequence control circuit is improved; various scanning modes are set, and when the ground penetrating radar needs to modify a scanning mode, hardware and software of the high-precision time-sequence control circuit do not need to be modified, and only parameter setting needs to be carried out through the SPI interface.

Description

technical field [0001] The invention relates to the field of underground target detection, in particular to a high-precision timing control circuit for ground-penetrating radar. Background technique [0002] According to the requirements of the equivalent sampling principle of the shock pulse system, the higher the equivalent sampling accuracy of the radar system, the more realistic the restored radar signal and the higher the target detection accuracy. The high-precision timing control circuit of ground penetrating radar is the key to realize the equivalent sampling data acquisition. It is the core technology of ground penetrating radar. It is used to start the sampling and holding of the antenna system and the A / D conversion of the control unit system. The sampling time of sampling ensures that the radar system obtains a high time resolution. [0003] The high-precision timing control circuit has a ramp comparison method and a programmable delay chip method. The ramp wav...

AI Technical Summary

Problems solved by technology

The ramp comparison method can adjust the step interval value Δt by changing the step wave step voltage, but the analog circuit is easily affected by noise and temperature, and the phase noise is large, so it is difficult to ensure the high precision requirement of the Δt value

Some programmable delay chip methods do not consider the synchronization problem in the implementation process, the jitter error is too large, and the jitter directly affects the stability of high-precision timing

In addition, the scan form is relatively simple, only step scan form or step back scan form

Images