• Title/Summary/Keyword: 펄스페어 추정치

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A Study on Poly-pulse Pair Estimation Method for Reduction of Bias Errors in a Weather Radar (기상레이다에서의 편향오차 감소를 위한 다중 펄스페어 추정기법에 관한 연구)

  • 이종길
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12B
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    • pp.2292-2297
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    • 1999
  • Some observed weather spectra show that nearly 25% of weather spectra are seriously skewed and can not be considered to be symmetric. However, the conventional pulse pair method was derived and has been evaluated under the assumption that the weather spectrum is symmetric and narrow. This means that the conventional pulse pair method may need reevaluation. Therefore, this paper analyzed the bias errors of pulse pair estimates in the skewed spectra. The bias errors of pulse pair mean estimates are more serious comparing with the pulse pair width estimates. In this paper, the poly-pulse pair method is suggested to reduce these bias errors of mean estimates. It was shown that the mean bias errors can be reduced remarkably using the newly suggested poly-pulse pair method.

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A Study on Spectrum Moment Estimation in an Acoustic Doppler Current Profiler (ADCP에서의 스펙트럼 모멘트 추정에 관한 연구)

  • Lee, Jonggil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.8
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    • pp.1790-1795
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    • 2013
  • The current velocity and turbulence information in each range cell can be obtained from the first and second Doppler spectrum moment estimates. However, the very widely used correlation method often called as the pulse-pair method has the inherent restrictions under the highly turbulent conditions since it does not satisfy the assumptions that the return Doppler spectrum should be symmetric and have a single peak value. Therefore, in this paper, the quality of pulse-pair estimates were compared with that of FFT estimates for problem analysis using various shapes of simulated Doppler spectra. It can be known that the pulse-pair method often yields meaningless results if the received signals are severely biased or multi-peak Doppler spectra in the Doppler frequency domain.

Clutter Removal in a Weather Radar Using an Adaptive Array Antenna (적응배열 안테나를 이용한 기상 레이다에서의 클러터 제거)

  • Lee, Jong-Gil
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.6C
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    • pp.398-402
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    • 2011
  • High resolution windspeed profile measurements are needed in a weather radar to provide the reliable information of rapidly changing weather conditions. However, it is necessary to remove both stationary and moving clutter to obtain the accurate pulse pair estimates. To overcome these problems, a simple adaptive array antenna may be applied to clutter removal. Using the simulated weather and clutter data, the clutter cancellation capability is analyzed for a weather radar with an adaptive antenna. The pulse pair estimates obtained from the adaptive weather radar are compared with those of the raw data.

A Study on Clutter Cancellation in a Weather Radar System Using a Phased Array Antenna (위상배열 안테나를 활용한 기상 레이다 시스템에서의 클러터 제거에 관한 연구)

  • Lee, Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.7
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    • pp.1173-1179
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    • 2008
  • Since there are very strong clutter returns in airborne and ground weather radars used for the detection of low altitude weather hazards, the reliable weather data cannot be extracted from the weak Doppler weather signal without cancellation of these strong clutter returns. However, the clutter cancellation in Doppler frequency domain is not an easy task since even the fixed clutter returns not to mention the moving clutter can have Doppler shifts due to the antenna rotation and operational environment. Therefore, it was shown in this paper a simple array antenna system can be used for the efficient clutter cancellation in the spatial domain. The weather signal, various moving and fixed clutters were modelled and simulated to prove the performance of this adaptive array system. Also, the degree of accuracy in pulse-pair estimates of a weather radar was compared and analyzed from the simulated weather data.

A study on the performance analysis of a weather radar using an adaptive array antenna (적응배열 안테나를 이용한 기상레이다 성능분석에 관한 연구)

  • 이종길
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.8
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    • pp.1990-1997
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    • 1998
  • It is very essential to remove a strong ground clutter and moving clutter for an extraction of accurate information from a Doppler weather radar. Therefore, this paper proposed the use of an adaptive array antenna to overcome the shortages of a conventional weather radar. In the first, a simulation method was suggested for the generation of clutter and weather signals. Using these data, the performance of a weather radar was analyzed under various conditions. It is shown that the quality of pulse-pair estimates was greatly improved from the simulation results.

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