The Method Of Frequency Measurement And Software Design Of The Broadband Doppler Velocity Log

Compared with the narrowband signal,the broadband coded signal has a higher time resolution and under the same conditions the broadband coded signal shows a better velocity accuracy。The broadband coding techniques which would be used in the Doppler Velocity Log(DVL) could greatly improve the system precision of velocity measurement, so the study of frequency measurement algorithm of the broadband signal would be the foundation of broadband coding techniques used in Doppler Velocity LogThe model of velocity measurement which is belong to the broadband Doppler Velocity Log is mainly studied in the paper and the broadband frequency measurement algorithm was carried out on the DSP.Firstly,the paper research the echo-signal model of DVL and the complex covariance power spectral moment estimates of correlated pairs (CPPC) which is used in the frequency measurement of the broadband coded signal. Based on the echo model and through the simulation and analysis between the broadband and the narrowband signal,some parameters which affect the frequency measurement accuracy were found and the conclusion is that the broadband coded signal has a better velocity accuracy than that of narrowband signal under the same conditions. In addition, papers also study a method which could solve the illegibility problem of the broadband frequency measurement algorithmIn the design of frequency measurement software, Software is programmed to develop DSP basing on hardware platform which makes digital signals processing arithmetic come true. Meanwhile the band-pass sampling techniques and the integral coefficient filtering techniques were studied in the paper, it could greatly reduce the computation work.At last, through the result of the lake trial data processing, the algorithm of the broadband frequency measurement was proved through the experimentation in the lake...