Study On The Key Technology Of Intensity Tomography Measurement By Underwater Laser

The autocorrelation function of the pseudorandom code is similar to that of the white noise, which has the randomicity .The pseudorandom code phase modulation system just works on the basis of this characteristic. The system, having excellent precision performance and maximal non-fuzzy distance capability, is one of the important directions of the measurement .The design and implementation of the system is studied and discussed, including the generation of pseudorandom code and its phase-modulation signal, the transmitter of receiver of signal, the correlation detection of pseudo-random code, etc.This thesis focused on the design of digital pseudorandom system and its hardware platform. The architecture of the hardware platform consists of DSP, FPGA, ADC, DAC and etc. And all of module will be implemented with VHDL, simulated and verified in Quartus II development environment. Measures the phase contrast of the original signal and the rebirthed signal to get the reality data .And the frequency and phase of the original signal is real-time controlled by DSP.In the processing of the correlation detection, the implementation principle and structure of digital correlator is analyzed in detail and the digital correlator of structure is designed and implemented by FPGA. The results show this correlator holds the excellent working performance.Finally, a project of digital pseudorandom system is designed and verified on the experimental platform, which is specially designed.