Research And Realization Of High Accuracy Frequency Measurement Technology

In vast ocean,the traveling ships needs the navigation system to supply the information for it,otherwise the ships will get lost in ocean;When the large-scale ships approach the wharf,needs to supply the precise speed information for it, otherwise the ships will crash the wharf,creates the serious accident.This thesis studies Doppler frequency measurement system is precisely to solve thesc two problems.The core of ship's velocity measurement is measuring echo signal frequency.This thesis is to study,design and realize the scheme of Doppler frequency measurement.The main tasks of this thesis are:research the general hardware architecture of Doppler log;develop a Doppler frequency measurement system which used the TMS320C6416 DSP chip as the core processor;programming the application software on DSP;joint every part of the system and get the trial data;processing the trial data at last.At the same time,this thesis emphasis on the frequency estimating algorithm of zero-crossing,covariance and FFT.Introduce their principle,formula,characteristic and function improvement.Finally,according to the simulation result and the experimental result,obtains the merits,the demerits and the suitable situation of each algorithm.This thesis can help choosing a suitable algorithm in the project application for different needs.Also can provide the beneficial enlightenment for Doppler measures frequent research.I sincerely hope that the content of this thesis can give the readers beneficial enlightenment and help.