• Title/Summary/Keyword: Pulse Doppler mode

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A Helicopter-borne Pulse Doppler Radar Signal Processor Development (헬기탑재 펄스 도플러 레이다 신호처리기 개발)

  • Kwag, Young-Kil;Jeun, In-Pyung;Choi, Min-Su;Hwang, Gwang-Yeon;Lee, Kang-Hoon;Lee, Jae-Ho
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.443-446
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    • 2005
  • This paper presents the results of the design and implementation of the airborne pulse doppler radar signal processor using high multi-DSP for the multi-function radar capability such as short-range, midium-range, and long-range depending on the mission of the vehicle. Particularly, the radar signal processor is developed using two DSP boards in parallel for the various radar signal processing algorithm. The key algorithms include LFM chirp waveform-based pulse compression, MTI clutter filter, MTD processor, adaptive CFAR, and clutter map. Especially airborne moving clutter Doppler spectrum compensation algorithm such as TACCAR is implemented for the multi-mode airborne radar system. The test results shows the good Doppler spectral separation for the clutter and the moving target in the flight test environment using helicopter

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A Helicopter-borne Pulse Doppler Radar Signal Processor Development using High Speed Multi-DSP (고속 Multi-DSP를 이용한 헬기탑재 펄스 도플러 레이다 신호처리기 개발)

  • Kwag, Young-Kil;Choi, Min-Su;Jeun, In-Pyung;Hwang, Gwang-Yeon;Lee, Kang-Hoon;Lee, Jae-Ho
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.23-28
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    • 2005
  • An airborne radar is an essential aviation electronic system of the helicopter to perform various missions in all-weather environments. This paper presents the results of the design and implementation of the airborne pulse doppler radar signal processor using high multi-DSP for the multi-function radar capability such as short-range, midium-range, and long-range depending on the mission of the vehicle. Particularly, the radar signal processor is developed using two DSP boards in parallel for the various radar signal processing algorithm. The key algorithms include LFM chirp waveform-based pulse compression, MTI clutter filter, MTD processor, adaptive CFAR, and clutter map. Especially airborne moving clutter Doppler spectrum compensation algorithm such as TACCAR is implemented for the multi-mode airborne radar system. The test results shows the good Doppler spectral separation for the clutter and the moving target in the flight test environment using helicopter.

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A Study on the Pulse Doppler System with M-mode Image and Spectrum Analyzer (주파수 해석기와 M-mode 영상을 갖는 펄스 도플러 장치의 개발에 관한 연구)

  • Jeong, Taek-Seob;Park, Sei-Hyun;Kim, Young-Kil
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1217-1220
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    • 1987
  • We have developed a Ultra Sound Pulsed Doppler System with two-dimensional M-mode image and Spectrum analyzer. The image of the M-mode is composed of time and depth axes. The Spectrum analyzer shows the spectrum of Doppler signal which represents the velocity component of time dependent blood-flow behavior. The spectrogram using Spectrum analyzer is composed of frequency and amplitude axes. The outputs of the system are audio signals, velocity curves, velocity profiles, M-mode images and spectrogram.

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Improvements of Pulse Doppler Gap Filling Algorithms for Portable Medical Ultrasound Imaging System (휴대용 초음파진단기를 위한 펄스 도플러 갭 필링 알고리즘의 개선)

  • Bae, MooHo;An, Hyung-Jun
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.8
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    • pp.580-589
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    • 2012
  • In this paper, we studied on Doppler gap-filling algorithms suitable for a portable or low-cost medical ultrasound imaging system, and as a result, found out algorithms based on mirroring or autoregressive model. Moreover, controlling the computational demand in the proper range, we improved the performances of these algorithms by solving their problems. Effectiveness of these modified algorithms is verified by computer simulations and experiments which used artificially generated Doppler signals and Doppler data acquired from human body through an actual ultrasound system.

A New Method for Extending Doppler Mean Frequency in Ultrasonic Imaging Systems (초음파 영상 시스템에서 새로운 도플러 평균주파수 확장 방법)

  • Kwon, Sung-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.1047-1056
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    • 2007
  • Basically, an ultrasonic imaging system has two fundamental imaging modes available. One is the B-mode imaging modality which provides an image of reflection coefficient, and the other is the Doppler color flow mode that maps blood flow inside the human heart and blood vessels. This paper presents a new method of detecting and compensating for aliasing that occurs when the Doppler frequency exceeds one-half of the pulse-repetition frequency (PRF). Its validity is shown by computer simulation. The new method not only extends the measurable Doppler frequency, but also helps to reduce the effect of noise. The results show that the aliasing can be compensated for correctly fur signal-to-noise ratios down to 20 dB.

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Design of Multi-Mode Radar Signal Processor for UAV Detection (무인기 탐지를 위한 멀티모드 레이다 신호처리 프로세서 설계)

  • Lee, Seunghyeok;Jung, Yongchul;Jung, Yunho
    • Journal of Advanced Navigation Technology
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    • v.23 no.2
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    • pp.134-141
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    • 2019
  • Radar systems are divided into the pulse Doppler (PD) radar and the frequency modulated continuous wave (FMCW) radar depending on the transmission waveform. In particular, the PD radar is advantageous for long-range target detection, and the FMCW radar is suitable for short-range target detection. In this paper, we present design and implementation results for a multi-mode radar signal processor (RSP) that can support both PD and FMCW radar systems to detect unmanned aerial vehicles (UAVs) at short distances as well as long distances. The proposed radar signal processor can be implemented based on Altera Cyclone-IV FPGA with 19,623 logic elements, 9,759 registers, and 25,190,400 memory bits. The logic elements and registers of the proposed radar signal processor are reduced by approximately 43% and 30%, respectively, compared to the sum of logic elements and registers of the conventional PD radar and FMCW radar signal processor.

Estimation of Doppler Spectrum Modes in a Weather Radar for Detection of Hazardous Weather Conditions

  • Lee, Jong-Gil
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3A
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    • pp.205-210
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    • 2002
  • In a Doppler weather radar, high resolution windspeed profile measurements are needed to provide the reliable detection of hazardous weather conditions. For this purpose, the pulse pair method is generally considered to be the most efficient estimator, However, this estimator has some bias errors due to asymmetric spectra and may yield meaningless results in the case of a multimodal return spectrum. Although the poly-pulse pair method can reduce the bias errors of skewed weather spectra, the modes of spectrum may provide more reliable information than the statistical mean for the case of a multimodal or seriously skewed spectrum. Therefore, the idea of relatively simple mode estimator for a weather radar is developed in this paper, Performance simulations show promising results in the detection of hazardous weather conditions.

Compact and versatile range-finding speedometer with wide dynamic range

  • Shinohara, Shigenobu;Pan, Derong;Kosaka, Nozomu;Ikeda, Hiroaki;Yoshida, Hirofumi;Sumi, Masao
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.158-161
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    • 1995
  • A new laser diode range-finding speedometer is proposed, which is modulated by a pair of positive and negative triangular pulse current superimposed on a dc current. Since a target velocity is directly obtained form a pure Doppler beat frequency measured during the non-modulation period, the new sensor is free from the difficulties due to the critical velocity encountered in the previous sensor. Furthermore, the different amplitude of the two triangular pluses are so adjusted that the measurable range using only one laser head is greatly expanded to 10cm through 150cm, which is about two times that of the previous sensor. The measurement accuracy for velocity of .+-.6mm/s through .+-.20mm/s and for range is about 1%, and 2%, respectively. Because the new sensor can be operated automatically using a microcomputer, it will be useful for application of a 3-D range image measurement of a slowly moving object.

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A Study on the Detection of Hazardous Weather Conditions by a Doppler Weather Radar (도플러 레이다를 이용한 기상위험 탐지에 관한 연구)

  • 이종길
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.3
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    • pp.533-542
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    • 1994
  • In a Doppler weather radar, high resolution windspeed profile measurements are needed to provide reliable detection of a hazardous weather condition. For this purpose, the pulse-pair method is generally considered to be the most efficient estimator. However, this estimator has some bias errors due to asymmetric spectra and may yield meaningless results in the case of a multimodal return spectrum in this paper, bias errors were analyzed and an improved method was suggested to reduece these errors. For the case of a multimodal or seriously skewed spectrum, the modes of spectrum may provide more reliable information than the statistical mean. Therefore, the idea of a relatively simple mode estimator is also developed.

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Design of Low-complexity FFT Processor for Multi-mode Radar Signal Processing (멀티모드 레이다 신호처리를 위한 저복잡도 FFT 프로세서 설계)

  • Park, Yerim;Jung, Yongchul;Jung, Yunho
    • Journal of Advanced Navigation Technology
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    • v.24 no.2
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    • pp.85-91
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    • 2020
  • Recently, a multi-mode radar system was designed for efficient operation of unmanned aerial vehicles (UAVs) in various environments, which has the advantage of being able to integrate and utilize methods of the pulse Doppler (PD) radar and the frequency modulated continuous wave (FMCW) radar. For the range detection part of the multi-mode radar signal processor (RSP), the hardware structure using the FFT processor and the IFFT processor is required to be designed in a way that improves efficiency on the area side. In addition, given the radar application environment that requires a variety of distance resolutions, FFT processors need to support variable-length operations. In this paper, the FFT processor and IFFT processor in multi-mode RSP range estimation are designed and proposed as hardware for a single FFT processor that supports variable length operation of 16-1024 points. The proposed FFT processor designed in hardware description language (HDL) and can be implemented with 7,452 logic elements and 5,116 registers.