• International Journal of Aeronautical and Space Sciences
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• v.6 no.1
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• pp.8-16
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• 2005

This paper describes target detection performance of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR process schemes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR, and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between target detection probability and signal to noise ratio. This paper concludes the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter, When range bins increase.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1860-1866
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• 2016

Helicopter-related collision accidents with structures mostly occur at landing, especially in a limited visibility environment, which necessitates some secondary equipment like a radar that can generate stationary clutter image. In this paper, we propose an algorithm that makes an image of stationary ground clutter in two dimensional range and azimuth angle domain. We present a mathematical model for the received signals from each clutter patch in the iso range ring and analyze their clutter and Doppler characteristics, assuming that a helicopter-borne radar has a rotational antenna. We propose a filter structure, which suppresses side lobe signal components while extracting a main lobe signal component, and suggest a solution for a problem stemmed from the filtering process. Finally, by conducting a simulation we show the performance of the suggested imaging algorithm on a two dimensional virtual scenario of the topographic clutter.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.2
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• pp.88-92
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• 1985

The performance of MTI signal processors against composite clutter depends not only on the power density functions of the clutter spectrum, but also on the average radar cross sections and the average doppler frequencies of each clutter. In this paper the effect of composite clutter composed of different kinds of clutter such as ground and weather on the MTI signal processors, is compared in terms of MTI improvement factors and the method of comparison is provided.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.27-32
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• 2010

77GHz FMCW(Frequency Modulation Continuous Wave) radar system has been used for automotive active safety systems. In typical automotive radar, the moving target detection and clutter cancellation including stationary targets are very important signal processing algorithms. This paper proposed the moving target detection algorithm which improve the detection probability and reduce the false alarm rate. First, the proposed moving target beat-frequency extraction filter is used in order to suppress clutter, and then the data association is applied by using the extracted moving target beat-frequency. Then, the zero-Doppler target is eliminated to remove the rest of clutter.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.92-95
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• 1991

Constant false alarm rate(CFAR) processors are useful for detecting radar targets in background for which all parameters in the statistical distribution are not known and may be nonstationary. The well known "cell averging" (CA) CFAR processor is known to yield best performance in homogeneous case, but exhibits severe performance in the presence of an interfering target in the reference window or/and in the region of clutter edges. The "order statistics"(OS) CFAR processor is known to have a good performance above two nonhomogeneous cases. The modified OS-CFAR processor, known as "trimmed mean"(TM) CFAR processor performs somewhat better than the OS-CFAR processor by judiciously trimming the ordered samples. This paper proposes and analyzes the performance of a new CFAR processor called the "maximum trimmed mean"(MX-TM) CFAR processor combining the "greatest of"(GO) CFAR and TM-CFAR processors. The MAX operation is included to control false alarms at clutter edges. Our analyses show that the proposed CFAR processor has similar performance TM- and OS-CFAR processors in homogeneous case and in the precence of interfering targets, but can control the false rate in clutter edges. Simulation results are presented to demonstrate the qualitative effects of various CFAR processors in nonhomogeneous clutter environments.

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.1
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• pp.39-46
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• 2024

In this paper, we propose an efficient method for estimating the number of people and their locations using multiple IR-UWB radar sensors. Using three IR-UWB radar sensors in the indoor space, the measured signal from the target is processed to remove the clutter using rejection methods. Then, to further remove the clutter and to determine the presence of the human, the time-frequency image representing the micro-Doppler is obtained and classified by a convolutional neural network. Finally, the system finds the number of human objects and estimates each position in a two-dimensional space. In experiments using the measured data, the system successfully estimated the location and number of individuals with a high accuracy ≈ 88.68 %.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.1
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• pp.96-99
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• 2016

Generally, bistatic clutter, contrary to the monostatic clutter, has nonlinear structure in Angle-Doppler domain due to the noncooperative motion of the transmitter and the receiver. In this paper, we first simulate the bistatic clutter structure resulting from the relative motion of the transmitter and the receiver and then analyze their relations through the bistatic clutter structure in Angle-Doppler domain. Also, we show the operation condition of the transmitter and the receiver leading to low rank of a covariance matrix of the bistatic clutter.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.275-282
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• 2019

Clusters generated by features such as mountains or buildings are considered as the contaminated data that are independent of atmospheric phenomena. The basic way to reduce the clutter signal is to install a clutter fence around the wind profiler. In order to investigate the effect of clutter fence on the wind profiler data, the wind vector collection rate and wind vector accuracy of wind profiler was investigated before and after clutter fence installation. The clutter fence of wind profiler contributed to improve the data quality as well as the data collection rate.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.407-417
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• 2019

When a free-falling ballistic missile intercepts a maritime target in a sea clutter environment at high grazing angle, detection performance of the ballistic missile's seeker can be rapidly degraded by the effect of sea clutter. To solve this problem, it is necessary to verify the performance of maritime target detection via simulations based on various scenarios. We accomplish this by applying a two-dimensional cell -averaging constant false alarm rate detector to a two-dimensional radar image, which is generated by merging a sea clutter signal at high grazing angle with a maritime target signal corresponding to the signal-to-clutter ratio. Simulation results using a computer-aided design model and commercial numerical electromagnetic solver in various scenarios show that the performance of maritime target detection significantly depends on the grazing and azimuth angles.