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In this paper, we present a new segmentation algorithm based on subband decomposition for SAR images. The decomposition of the SAR images into subband images is performed by 2D four channel non separable filter bank having lattice structure. The four channel filter bank with lattice structure has perfect reconstruction property, while it guarantees good stop band attenuation for each of the analysis...
Weather radar polarimetric techniques have been widely studied due to their potential to improve radar rainfall estimation and to infer on the microphysical characteristics of clouds and precipitation. Nowadays, polarimetric techniques are receiving an increasing attention from meteorological services. In fact, programs aiming at upgrading national weather radar networks with polarimetry are ongoing...
The objective of this work is to develop optimal polarimetric Constant False Alarm Rate (CFAR) ship detection system. Polarimetric transformation/decompositions, clutter analysis, modeling, Principal Component Analysis (PCA), and multi-CFAR detection are the necessary components of optimal polarimetric CFAR ship detectors. The resulting CFAR detector outperforms the conventional polarimetric CFAR...
In this paper, a robust CFAR detector, composed of an automatic dual censoring algorithm and the cell averaging CFAR detector, is proposed for non-homogenous environment. The new detector is named an automatic dual censoring cell averaging (ADCCA). The proposed detector does not require any prior knowledge about the background environment and uses two threshold values to reject the unwanted samples...
In the last years, in order to investigate the distribution of water in the upper part of the Matianpsilas crust, two different instruments have been developed, and operative up to now: Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and SHA allow RADar (SHARAD). Both the instruments are low frequency (1.8-5 MHz for MARSIS and 20 MHz for SHARAD) Ground Penetrating Radar (GPR) in...
Intense RF (radio frequency) interference is the one of the impediments in target detection for high frequency surface wave radar (HFSWR). A novel type of HFSWR, bistatic HF surface wave SIAR (synthesis impulse and aperture radar), has been presented recently. In this paper, the RF interference of this radar is analyzed. Combining with the theoretical analyses and experimental samples, the features...
This paper describes a detection and localization method for high speed moving targets using a short-range ultra-wideband (UWB) impulse radar. Equivalent time sampling impulse radar with an antenna array is used to transmit ultra short-pulse and receive the signal reflected from moving targets. A time domain multi-threshold detection method is proposed to detect the useful weak signal buried in noise...
Airborne radar has evolved from early systems where almost all radar characteristics were fixed to todaypsilas highly flexible, software-driven systems. The most recent advance has been the widespread adoption of active electronically scanned array (AESA) antennas, which has given the system designer unprecedented control of antenna characteristics. However, in common with most conventional radars,...
Numerous space-borne X-band synthetic aperture radars (X-SAR) systems will be launched by European agencies in the coming decade commencing this year. Those X-SARs can measure precipitation over land, thereby significantly augmenting the sensors that comprise the Global Precipitation Mission (GPM). This will incur relatively little incremental cost because they have already been funded. X-SAR measurements...
Radar measurements of a radar calibration sphere test target suspended in sea surface multipath propagation conditions are reported. Wideband measurements together with high range resolution (HRR) processing were employed to resolve the direct reflection component and sea surface reflected multipath components of the received signal. The temporal correlation characteristics of the resolved single...
In this paper we apply a data association in track-before detect (TBD) with a polar Hough transform (PHT) in a radar network. The proposed algorithm is applied in multiple input multiple output (MIMO) radar system. We study the sensitivity of TBD multi-radar system as a function of the errors of target trajectory parameters measurement. The results are obtained in the presence of Randomly Arriving...
Circular shifting and windowing have been introduced to improve the performance of Doppler centroid tracking (DCT) in inverse synthetic aperture radar (ISAR) image focusing when the target has prominent scattering centers. However, the conventional unified windowing method is hard to implement and affects the performance of DCT. An adaptive windowing method based on ISAR target extraction is proposed...
This paper describes three different continuous wave (CW) radar waveforms which are applied in automotive radar sensors. The radar sensor should be able to detect all objects inside the observation area and to estimate range, radial velocity and azimuth angle simultaneously even in multi target situations. A classical Linear Frequency Modulation (LFM) waveform provides a very high range and velocity...
A new efficient method to obtain high resolution ISAR images in the case of missing observation data is presented. The available data segments are modeled by 2-D linear prediction of 2-D Cartesian frequency spectra using 2-D orthogonal lattice filters. Then the prediction models are used to estimate the missing data segments. It is shown that the IFT processing of the resulting data achieves better...
We present a novel receiver structure for the detection and parameter estimation of linear frequency modulated signals. The proposed structure is based on the relations between the fractional Fourier transform and the ambiguity function. It has been shown that the optimal ML receiver, which is the peak detector in the ambiguity plane, can be implemented at a reduced search complexity with the proposed...
Helicopters are essential for any mission of humanitarian or assisting nature in disaster areas. Very often they have to cope with missing infrastructure and extreme environmental conditions. Besides darkness and adverse weather, dust and snow are two of the most dangerous conditions for helicopter landing. At the time being, helicopter pilots have no adequate sensors to get information on height...
The performance of a target recognition method based on template matching depends on the quality of the template database to a large extent. This paper introduces a method of establishing an extensible template database of range profiles based on the minimum entropy rule. The new method guarantees the quality of the template database from two sides: the signal-to-noise ratio and the completeness of...
Chaff, a typical passive deceivable interference, is commonly used to cheat radar reconnaissance by producing high fidelity echoes in military counter-mission. It is difficult and challenging to distinguish chaff from ship based on their echoes. Firstly a sparseness characteristic analysis is implemented about ship and chaff return in time-domain and frequency-domain, respectively, which conclude...
This paper describes the COSMO-SkyMed SAR instrument and its active phased array, developed by Thales Alenia Space Italia under contract of Italian Space Agency and Italian Ministry of Defence. Major focus is given to the description of the antenna, the architectural solutions and the technological results.
Through-the-wall radar imaging attempts to image complex scenes within enclosed structures. While most of the high-resolution imaging techniques assume point targets, indoor imaging requires dealing with single or multiple walls which are extended targets in nature and violate the point-target assumption. In order to provide high quality imaging, we need to consider point targets and extended targets...
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