Transient Electromagnetic Standard Source Developed And Receiver Examination

With the depth of transient electromagnetic method, transient electromagnetic instrument moreand more widely used in geological exploration, so the transient electromagnetic methodresearchers study high-resolution transient electromagnetic instruments. Transient electromagneticinstruments measured signal curve is similar to the e exponential decay waveform. Use eexponential decay signal to test transient electromagnetic instrument closing the actual workingcondition to make the test more accurate. Further testing procedure of the receiver need to add asynchronization signal, touch off receiver acquisition. This is the unique test method for the receiver,and there don’t have signal generator that transmit the synchronization waveform and test arbitrarywaveform at the same time on the market. The use of effective methods of testing and calibrationmeans is to improve the resolution and accuracy of the premise of the transient electromagneticinstruments. Therefore, this paper designed a transient electromagnetic standard signal source forthe transient electromagnetic receiver. Using the theoretical waveform verify the signal source and establishing the receiver calibration model initially.This paper analyzes the principle of transient electromagnetic signal, transient electromagneticresponse characteristics and field testing of transient electromagnetic signal attenuation curvecharacteristics, to provide theoretical basis for the development of the standard signal source. Toachieve the accuracy of the secondary field of electromagnetic signals design the input and outputbuffers and match the output resistance for the DA work better linearity and design a precisionreference power supply. We designed dual synchronous signal drive to maintain the normaloperation of the entire test system. To improve the transmission efficiency of the waveform data, thefirst to use bit operating of the GPIO port optimal control timing to reduce the timing of datatransfer time. Recycling the DMA data transfer channels, thereby shortening the overall datatransfer time. To verify the effectiveness of the standard signal source, using the oscilloscopepreliminary to test signal source output waveform, comparing the theoretical signal with acquisitionsignal by online debugging with receiver, we measured the signal source output error range in100μV and meet the design requirements. On this basis, we establish the receiver calibration model initially. We establish the Calibration model based on artificial neural network from using the40groups of theoretical signal and the measured signal. And we choose20groups for training, andanother20for the test, the test accuracy rate of90%.