The Study And Realization Of Real-time Correlator-stacker’s Fast Arithmetic

Real-time correlater and stacker is a very important instrument in vobroseismic prospecting, we can use it to acquire useful observational seimic section in the field, and prospect experts can make the quality control of signal, at the same time compress data to lessen data quantity、 enhance data transmission efficiency and memory efficiency. Stacking is to suppress the noise in original signal and enhance the signal-to-noise, this is very important to seismic prospecting. Before memory, the system can take out some noise which has overwhelm preponderant than signal, do some process to the signal of seismic signal recorded and swept then we get high fidelity seismic data.In pertroleum industry, the requirement of Real-time correlater and stacker first is only for watch in field, precision and speed are not high, but along with the development of prospect technology, the collection amount of data increase, and requirement of the precision and speed change. Today, Real-time correlater and stacker can do8000channels more Real-time correlate and stack and other pretreatment with full precision.The size of Seismic data collection scene is so huge that the process speed directly effect the work efficiency in field. So, the research and actualize of real-time correlater and stacker’s fast arithmetic has a very important significance for advance work efficiency in field、saving the prospect cos、enhance data precision、reduce prospect difficulty. The design construct the software platform of real-time correlater and stacker and validate arithmetic. along with the fast development of pertroleum prospect scale, the requirement of software process’s performance becomes higher and higher, the data amount increase decuple even centuplicate compare past, the precision and speed require higher, it is a big challenge to developer. Only optimize and actualize the arithmetic scientif icly, can the quick result of using real-time correlate and stack’s fast arithmetic be incamate sufficiency, and can resolve various problems of seismic prospect in petroleum industry.Real-time correlater and stacker can be realized by hardware like DSP and so on. Due to the huge amount of data need to process and the real-time require of the system, traditionally use special CMOS chip to realize, but hardware hard to upgrade、maintenance and use hardware to speedup. Along with the development of modern computer, high speed computer with multicore and multiprocessor’s appear make it easy to realized by software will be better,it’s facility to upgrade、maintenance and speedup the system.How to improve the software collectivity performance, is a difficult problem of software develop and optimize, these years, in the information theory industry, multicore processor technology makes a notability advance effection, multicore processor is a computer which has all central processing units’memory shared, the same address of different central processing units show the same address in shared memory. So to achieve the design, the key technique is to assign task to multicore processor rationally and process parallelly.If we say Sun、IBM take multicore and multithread to a new era, well then in the year2006Intel and AMD make the parallel process technology hot. The parallel uptrend in year2007even hotter, additionally the restrict of hardware power and heat dissipation, with no doubt multicore parallel process become the only way to improve performance, and multicore parallel process will be mainstream in software development.Furthermore, Fast Fourier Transform Algorithm’s improve also is a important part. Only make the calculation amount smaller in arithmetic, exactness in precision, faster in processing, can make real high efficiency. The study make a research in-depth to the arithmetics of real-time correlater and stacker, and analysis the arithmetics for example: linearity correlation、cycle correlation、Ver-stack、Div-stack、Clipping、 Zeroing、ZeroingGradually、ZeroingCross and so on, according to the specialty、calculation amount、variable character effect of eath arithmetic,conclude the factors which effect it’s function, discuss the most excellent arithmetic, resolve the problem that the old arithmetic can’t process huge throughput. According to different kind of noise, the system use different method to edit, consider the development actuality in and out of country, design a seismic stacker model. A method to optimize is proposed, at last sum up the notes during design the real-time correlater and stacker system, using the newest high performance multicore processor and multithread program technology accomplish the software model’s optimum scheme of real-time correlater and stacker system. Real-time correlater and stacker system use multicore processor technology, and use Cross-platform GUI tools like Qt designer, and use matlab to approve it’s correctness, the circumstance of software use linux operating system which has a stable performance、transplantable and sustain multithread parallel process, after reading many literature, compared the speeds, improve the old FFT arithmetic, using OpenMP、FFTW to optimize the software, according to the character of multicore processor computer, rational distribute task to optimize the fast arithmetic.The design construct a software platform to test and fastly actualize program code of arithmetic.The research and actualize of fast arithmetic has a important significance for improving software performance、 upgrading、extend it’s application area, the study also has a very important reference value for other areas where need fast realize correlation operation.