Study On The M-Sequence Correlation Identification And Its Application To Induced Polarization Prospecting For The Method Of Suppressing Noise

Pseudo-random correlation identification method plays an important role in system identification technology which is widely used in industrial production. M-sequence is a common-used pseudo-random sequence and has been widely studied. Because of its suitable correlation properties, m-sequence can limit the noise affection to a low level. It is used to do system detection in weak signal, and has an accurate identification result.Induced polarization method (IP) is an important method in electrical prospecting and is used to do geophysical exploration usually. But its result is easy to be affected by the noise, which may lead to a wrong explanation, so it is need to suppress the noise when prospecting and data processing. This paper is aim to produce a way to use m-sequence correlation identification technology in IP prospecting method to suppress the noise effectivelyThis paper includes two major parts:(1) Study on the method to use m-sequence correlation identification technology in real situations. M-sequence correlation identification has many complex steps. This paper designs a program to create the m-sequence, and adjust the original method of correlation calculation to the real prospecting situation. And then, this paper analyzes the result of the identification calculation and the effect of suppressing noise as well.(2) Study on the way to apply the m-sequence correlation identification technology to IP prospecting. Charge the earth with electric current in the form of m-sequence, and get the impulse respond of the earth according to proper calculation method, it is the way to do IP prospecting combing with correlation identification technology. This paper carries out a simulation experiment based on this way. First step, create an IP model and calculate the outcome respond when supply an m-sequence electrical current. Some random noise will have been added to the outcome respond for the suppressing noise analysis. Second step, carry out correlation calculation with this outcome respond to get impulse respond of the system. At the same time, analyze the effect of suppressing noise compare to none correlation calculation method. The last step, calculate the frequency respond with proper time-to-frequency technology and inverse the parameters of the IP model to finish the whole simulation procedure.Correlation identification can suppress the noise effectively, according to the simulation result of the correlation identification calculation. But it needs a correct way to get the impulse respond from correlation calculation result. There is another conclusion that it is reasonable to do IP prospecting combined with the m-sequence correlation identification technology, and will have the visible result in suppressing noise, which has been proved by the simulation result. But the result of identification is impulse respond of the target electrical model, so it needs to be converted from time domain data to frequency domain data to get the electrical model parameters finally.