• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.61-67
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• 1999

A laser Doppler vibrometer based on the laser heterodyne interferometry is employed to measure the vibration velocity of vibrating objects. In this paper, we propose a real time analog signal processor of a laser Doppler vibrometer to reduce the degradation of Doppler signals mainly caused by environmental noises. In the proposed real time signal processor of an laser Doppler vibrometer, a pre-processor and a logical motion direction detector are designed to reduce the detection errors of the object motion direction. Also, a noise detection and rejection circuit is designed to reject the unfiltered noises.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.333-340
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• 2003

Doppler processing is the heart of pulsed Doppler radar. It gives a clutter elimination and coherent integration. With the improvement of digital signal processors (DPSs), the implementation using them is more widely used in radar systems. Generally, so as for Doppler processor to process the input data in real time, a parallel processing concept using multiple DSPs should be used. This paper implements a programmable Doppler processor, which consists of MTI filter, DFB and square-law detector, using 8 ADSP21060s. Formulating the distribution time of the input data, the transfer time of the output data and the time required to compute each algorithm, it estimates total processing time and the number of required DSP. Finally, using the TSG that provides radar control pulses and simulated target signals, performances of the implemented Doppler processor are evaluated.

• 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

• 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.

• Korean Journal of Remote Sensing
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• v.21 no.2
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• pp.163-171
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• 2005

I have developed a processor for synthetic aperture radar (SAR) raw data compression using range-doppler algorithm for educational purpose. The program realized a generic SAR focusing algorithm so that it can deal with any SAR system if the specification is known. It can run efficiently on a low-cost computer by selecting minimum size out of a whole dataset, and can produce intermediate images during the process. Especially, the program is designed for educational purpose in such a way that Doppler centroid and azimuth ambiguity can be determined graphically by the user. By distributing the source code and the algorithm to public, I intend to maximize the educational effect on understanding and utilizing SAR data. This paper introduces the principle of SAR focusing algorithm embedded on the eSAR processor and shows an example of data processing using ERS-1 raw data.

• 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.

• Korean Journal of Remote Sensing
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• v.19 no.6
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• pp.421-430
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• 2003

The extraction technique for Doppler information(Doppler centroid frequency(f$_{dc}$) and it's rate(f$_{r}$) is very important to make an image from the radar echo signal data. Clutterlock and auto-focusing techniques have been widely used to extract accurate Doppler information. But both techniques are not easy to implement in SAR processor and need quite lots of time to calculate accurate f$_{dc}$ and f$_{r}$ because they are generally based on echo signal data only. In this paper we suggest hybrid method for Doppler extraction using both of echo signal data and orbital and attitude information of satellite. In this method CDE(Correlation Doppler Estimation) technique is only used to estimate exact modular f$_{dc}$ using received echo signal data and rest of other algorithms are based on simple mathematical model of geometry between satellite and ground targets as well as the Doppler frequency ambiguity resolving problem. The experimental results using Radarsat-1 signal data shows that the proposed method can be effectively used for the extraction of Doppler information.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.68-69
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• 1998

Discriminating the clutter signal from Doppler signal is the main function of CDP(color Doppler processor). Up to now, a general method of eliminating clutter signal is using IIR high pass filter. There are many filters that were introduced in other paper. In this paper, we propose the new method of filtering clutter signal. To the new method, we adopt an appropriate filter that can eliminate clutter filter most effectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1147-1156
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• 2001

In this paper, a new design architecture of radar signal processor in real time is proposed. It has been designed and implemented under the consideration to minimize the inter-processor communication overhead and to maintain the coherence in Doppler pulse domain and in range domain. Its structure can be easily reconfigured and reprogrammed in accordance with an addition of function algorithm or a modification of operational scenario. As we designed a task configuration for parallel processing from measures of computation time for function algorithms and transmission time for results by signal processing, data exchange between processors for performing of function algorithms could be fully removed. Morocco-2 board equipped ADSP-21060 processor of Analog Devices inc. and APEX-3.2 developed for SHARC DSP were used to construct the radar signal processor.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.5
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• pp.361-369
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• 1991

The optics and the signal processor of dual beam laser Doppler velocimeter(LDV) was fabricated. By using the dual beam and the forward scattering, the optics part of LDV was fabricated. And the signal processor of LDV was designed by the frequency counter type using new 11:6 period timing device in order to remove error signals, and was made of the reference clock of a 500 MHz ECL oscillator. Doppler frequencies from 10KHz to 70MHz can be measured using the signal processor. In the accuracy of the period counting part, from 1.81x10**-4% to 1.27% is estimated, and in the accuracy of the validation logic part, from 0.78% to 14.78% is estimated.