Anechoic chamber measurements for circular isar imaging at Mersin University’s Meatrc Lab (original) (raw)
Related papers
Back-projection algorithm for ISAR imaging of near-field concealed objects
2011 XXXth URSI General Assembly and Scientific Symposium, 2011
In this study, the detection of metal objects concealed under clothes is investigated through millimeter-wave inverse synthetic aperture radar (ISAR) imaging. A metallic gun is selected as the target and W-band ISAR measurements for a two-dimensional scanning geometry are carried out in our anechoic chamber measurement facility. The ISAR images of concealed object are reconstructed using the near-field back-projection algorithm. The obtained images indicate the efficient detection and identification of the gun covered with different textile types.
The millimeter-wave ISAR imaging of concealed objects
2011 XXXth URSI General Assembly and Scientific Symposium, 2011
The detection of concealed objects like weapon, explosives, and other dangerous items became very important problem for defending people against terrorist attacks. Recent time, many methods have been developed but number of methods are not efficient to effectively solve this problem. The main aim of the research in this work is devoted to the detection of concealed dangerous objects by increasing sensitivity and resolution in obtained images. In this paper, we propose to use inverse synthetic aperture radar (ISAR) technology for the detection of hidden items in the millimeterwave length. The millimeter-wave ISAR imaging of concealed cubes and a gun are studied. The theoretical background employed for the reconstruction of measurement results is briefly described. The millimeter-wave ISAR measurement setup is presented. Then, measurements carried out for different scenarios are explained. Finally, the reconstructed results are shown for all conducted measurements.
The millimeter-wave imaging of concealed objects
Antennas and …, 2011
The detection of concealed objects like weapon, explosives, and other dangerous items became very important problem for defending people against terrorist attacks. Recent time, many methods have been developed but number of methods are not efficient to effectively solve this problem. The main aim of the research in this work is devoted to the detection of concealed dangerous objects by increasing sensitivity and resolution in obtained images. In this paper, we propose to use inverse synthetic aperture radar (ISAR) technology for the detection of hidden items in the millimeterwave length. The millimeter-wave ISAR imaging of concealed cubes and a gun are studied. The theoretical background employed for the reconstruction of measurement results is briefly described. The millimeter-wave ISAR measurement setup is presented. Then, measurements carried out for different scenarios are explained. Finally, the reconstructed results are shown for all conducted measurements.
ISAR for concealed objects imaging
SPIE Proceedings, 2015
A new promising architecture of microwave personnel screening system is analyzed in this paper with numerical simulations. This architecture is based on the concept of inverse aperture synthesis applied to a naturally moving person. The extent of the synthetic aperture is formed by a stationary vertical linear antenna array and by a length of subject's trajectory as he moves in the vicinity of this antenna array. The coherent radar signal processing is achieved by a synchronous 3D video-sensor whose data are used to track the subject. The advantages of the proposed system architecture over currently existing systems are analyzed. Synthesized radar images are obtained by numerical simulations with a human torso model with concealed objects. Various aspects of the system architecture are considered, including: advantages of using sparse antenna arrays to decrease the number of antenna elements, the influence of positioning errors of body surface due to outer clothing. It was shown that detailed radar images of concealed objects can be obtained with a narrow-band signal due to the depth information available from the 3D video sensor. The considered ISAR architecture is considered perspective to be used on infrastructure objects owing to its superior qualities: highest throughput, small footprint, simple design of the radar subsystem , non-required cooperation of the subject.
A study on millimeter-wave imaging of concealed objects: Application using back-projection algorithm
Progress In …, 2012
Millimeter-wave (MMW) imaging is a powerful tool for the detection of objects concealed under clothing. Several factors including different kinds of objects, variety of covering materials and their thickness, accurate imaging of near-field scattered data affect the success of detection. To practice with such considerations, this paper presents the two-dimensional (2D) images of different targets hidden under various fabric sheets. The W-band inverse synthetic aperture radar (ISAR) data of various target-covering situations are acquired and imaged by applying both the focusing operator based inversion algorithm and the spherical back-projection algorithm. Results of these algorithms are demonstrated and compared to each other to assess the performance of the MMW imaging in detecting the concealed objects of both metallic and dielectric types.
Focused ISAR Imaging of Rotating Target in Far-Field Compact Range Anechoic Chamber
International Conference on Aerospace Sciences and Aviation Technology
A case study of a modified Inverse Synthetic Aperture Radar (ISAR) imaging technique for different target geometries in the Far Field RCS measurement Compact Range is presented. The processing applied to the experimental data is a combination of two high resolution processes: dev of High Range Resolution profile (HRR) in the down range using stepped frequency waveform covering a total band of 4GHz, and the development of high resolution profile in cross-range is achieved using ISAR technique. The manuscript shows the use of Polar reformatting algorithm with Shannon reconstruction technique for correcting migration through resolution cells to obtain a better focused image of rotating targets.
Microwave radiation imaging using inverse synthetic aperture radar technique
Elektronika ir Elektrotechnika, 2015
Double-ridged horn antennas were used in ultra wideband radar system to create microwave radiation images. The images were obtained using inverse synthetic aperture radar technique. Transfer function of the calibrated radar system was close to one up to 22 GHz. High quality images of metallic and organic objects were created due to unique characteristic of ultra wideband radiated pulse. Metallic objects covered by visually opaque obstacles became detectable. The components of measurement setup and the data processing are both important for the formation of these images. The obtained results confirmed the ability of ultra wideband radar to form images for various practical applications including security systems. Higher frequency of such radar system can be raised up to 40 GHz-50 GHz.
Chapter 2 - Inverse Synthetic Aperture Radar Imaging
This chapter deals with the fundamental concepts of the synthetic aperture radar measurements and two di erent approaches for cross-sectional imaging applied in imaging radars. The discussion begins with giving the di erences between direct imaging and synthetic imaging. The disadvantages of the direct imaging method is emphasized by t o u c hing on the two basic concepts : \ the range and the cross-range resolution " of a radar system. A linear antenna array model is used to describe the synthetic aperture in section 2.3. In section 2.4., the discussion is restricted to ISAR and the formulation of image reconstruction in ISAR system is derive d . I t i s s h o wn that the re ectivity of the object and its frequency spectra constitutes Fourier Transform pair under certain assumptions. Section 2.5, after discussion of the limitations of Fourier technique, brie y introduces AR modeling method to overcome these di culties. This linear modeling technique which is also known as Maximum Entropy method is popular among many practitioners including radar applications 5], 24], 28].
B14. Active millimeter-wave imaging system for hidden weapons detection
2012 29th National Radio Science Conference (NRSC), 2012
In recent years, the need for developing an accurate human body imaging systems for concealed weapons becomes urgent due to the increase of the international terrorism. In this paper, an experimental system for hidden weapons detection is introduced. The system is based on the principles of Synthetic Aperture Radar (SAR) and monostatic radar. The proposed system transmits a very short pulse generated by a vector network analyzer (VNA) to illuminate a three layers target made from jeans, natural leather and reinforced papers. The target construction is chosen to emulate the presence of the human body. The imaging process is carried out by interpolating successive time domain measurements of the probe reflection coefficient S 11 at different points. Two types of scanning probes are used the first one is a standard millimetre-wave (MMW) horn antenna while the other one is a hybrid microstrip / horn antenna. The system shows a great ability for imaging and detecting a hidden metallic targets under the jeans layer of the target.
Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense XIII, 2014
This paper describes the architecture of a microwave radar system intended for imaging concealed objects under clothing as a subject walks through the inspection area. The system uses the principle of inverse aperture which is achieved by a person's movement past a stationary microwave sensor array. In the system, the vertical resolution is achieved by arranging microwave sensors vertically while the horizontal resolution is due to the subject's horizontal motion. The positioning of the objects is achieved by employing a synchronous video sensor that allows coherent radar signal processing. A possible radar signal processing technique based on signal accumulation is described. Numerical experiments are conducted with the described object trajectory model. The influence of positioning errors attributed to the video positioning system is also modeled numerically. An experimental setup is designed and proposed to evaluate the suggested signal processing techniques on real data with an electro-mechanical scanner and single transceiver. It is suggested that the signal acquisition with the system can be accomplished using the stop motion technique, in which a series of changing stationary scenes is sampled and processed. Experimental radar images are demonstrated for stationary objects with concealed items and considered as reference images. Further development of the system is suggested. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/06/2014 Terms of Use: http://spiedl.org/terms Proc. of SPIE Vol. 9074 907402-2 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/06/2014 Terms of Use: http://spiedl.org/terms