Broadband multiple correlation flow velocity measurement method

Abstract

The invention discloses a broadband multiple correlation flow velocity measurement method. Echo signals are sampled by adopting a time-interleaved sampling technology so that a discrete sampling sequence is obtained; multiple correlation algorithm processing and cross spectrum autocorrelation algorithm processing are respectively performed on the discrete sampling sequence; the number of multiple correlation points is increased in the process of multiple correlation algorithm processing, and real-time performance of flow velocity measurement is guaranteed by adopting odd and even paths of parallel multiple correlation processing; and cross spectrum interpolation time delay estimation is performed on the time-interleaved sampled data by cross spectrum autocorrelation algorithm processing so that a time delay value is obtained, and the time delay value is adopted to roughly measure the flow velocity value to act as the judgment standard of a flow velocity size interval, assist multiple correlation algorithm flow velocity measurement and correct the range of flow velocity measurement. Advantages are that multiple correlation algorithm processing and cross spectrum autocorrelation algorithm processing are supplementary for each other, sampling rate of the signals is enhanced by adopting the time-interleaved sampling technology, and multiple correlation algorithm flow velocity measurement is assisted through combination of the roughly measured flow velocity value of the cross spectrum autocorrelation algorithm so that measurement precision is high and measurement range is wide.

Description

technical field [0001] The invention relates to a flow velocity measurement method, in particular to a broadband multiple correlation flow velocity measurement method. Background technique [0002] With the increasing scarcity of resources, the development of marine water resources has become an urgent need for economic development. The flow velocity of ocean waters is an important parameter of the environment of ocean waters, and it is also an important basis for activities in ocean waters. Existing flow velocity measurement methods are mainly based on broadband complex correlation technology. The document "Research on Velocity Measurement Method of Wideband Doppler Current Meter" proposes a flow velocity research based on broadband multiple correlation algorithm. In this document, the specific process of flow velocity measurement is as follows: firstly, the pulse signal generator is used to generate a single-frequency pulse signal, and the M-sequence code is used to binar...

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Problems solved by technology

[0003] In this flow velocity measurement method, the echo signal is a random signal containing noise. The strength of the echo signal, noise interference, and the propagation loss of the echo signal all affect the accuracy of the flow velocity measurement. The complex correlation algorithm can filter out certain white noise. , has better anti-interference ability, so the flow velocity measurement method has higher accuracy, but in the process of processing the echo signal by the complex correlation algorithm, the phase information of the complex correlation function of the echo signal obtained is periodic, The measurement range of flow rate is limited, so the method has a narrow range

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