Sotfware System Design And Antenna Simulation Of GPR

Ground-penetrating radar (GPR) is one of the methods of ahead of geologicalforecast non-destructive detection. It can effectively predict the tunnel face frontgeological conditions in order to reduce the geological disasters in the constructionprocess. GPR is the use of high frequency electromagnetic wave to reflect at theinterface of different media to achieve the detection of the target area. The instrumentsystem consists of four parts: ultra-wideband (UWB) transceiver antennas, UWBpulsar module, data acquisition module and the host computer.It is used avalanche transistor to generate a significant nanosecond time domainpulse technology as ultra-wideband pulse source circuit.And it is designed asingle-stage avalanche transistor serially concatenated narrow pulse generating circuit,The pulsar designed in the paper has simple structure and stable performance..Acquisition and control module use a digital storage oscilloscope.MCUmicrocontroller produce the synchronization signal to trigger the avalanche pulsecircuit. Data acquisition modules achieve the synchronization of transmitter andreceiver connected by shielded cable launch system and acquisition system.GPR software system bases on the Windows XP operating system and use VisualBasic6.0language development. In order to facilitate observation of the operator,GPR software system use real-time imaging technology. API function BitBlt directlyin memory between the faster occupies a very short time. The visual effects like thescreen scrolls. The total is the latest collection of data displayed on the screen. Theimage display is divided into the A-scan and B-scan image display. A-scan imagesdraw the Wiggle curve method. B-scan include waveform stacked, gray stacked, colorstacked. Waveform stacked resembles A-scan images in chronological order. Thegrayscale accumulation map and color stacked use the area fill color stacked imagingdivision of the color gamut. In order to be able to clearly reflect underground geological situation, it is used linear interpolation of color stacked waveform stackedfor further improvement.Data preprocessing and data displayed are at the same time. You can moreclearly and accurately reflect the tunnel face front geological structure. In order toweaken clutter interference and enhance the strength of the echo signal, the use ofreal-time gain curve of the echo waveform correction. Real-time gain curve is drawnusing the Lagrange interpolation polynomial method. Average filtering method, datanoise reduction can improve the signal to noise ratio in order to avoid waveformdistortion, and give the corresponding experimental results.We are discussed the performance indicators of ground-penetrating radar antenna.The actual requirements of the tunnel geological exploration project in the geologicalenvironment of the simulated tunnel using the Gaussian pulse with a band80MHz-600MHz and the range of100V. The bow-tie antennas use CST software onthe planar structure. The spatial structure of the cylindrical antenna, planar structurefourth elliptical antenna simulation analyze of the echo signal and antennatransmission coefficient. And actual production of a low frequency plane butterflydipole antenna, ultra-wideband bow-tie antennas use univocal Gaussian pulse sourcecircuit with lumped resistance flu loaded fast matching.