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This paper presents an accurate source number detection method for low-cost array system based on nested array and Khatri-Rao product approaches. Source number estimation accuracy can be enhanced by increasing the number of array elements, but it is often limited due to hardware and software cost. The authors have already proposed a low-cost array receiver system using switches which can reduce receiver...
The spatial localization of passive UHF (ultra-high frequency) radio-frequency identification (RFID) tags is an emerging technology that has reached a high level of interest in industry and research. Most solutions are based on classical receive beamforming techniques, like the angle-of-arrival estimation, that are prone to multipath and deliver low localization accuracies. Therefore, a new approach...
Herein is proposed a novel high-steep rock slope landslide monitoring system based on the configuration of multi-static multiple-input multiple-output synthetic aperture radar (MIMO-SAR). In this system, three spastically distributed radars are employed. Each is a Ku-band MIMO-SAR, transmitting mutually orthogonal waveforms and sensing the slope movement from different view angles. The three radars...
A novel radiation pattern measurement system for VHF and UHF antennas has been recently developed using the Unmanned Aerial Vehicle (UAV) technology. This paper discusses the effect of the UAV orientation and the applicable corrections on the pattern extraction procedure, in order to increase the accuracy and repeatability of the measurements.
The adaptive cross approximation algorithm is invoked for the fast construction of the method-of-moment matrix involving source basis functions for the currents and a set of auxiliary test functions that samples the radiated electromagnetic (EM) field. Once the adaptive cross approximation coupling matrix is constructed, the far and near fields from a source current are obtained directly through a...
A method for electromagnetic radiation source identification is proposed. The spatial characteristic of a radiation source is taken as the unique parameter for support vector machines (SVMs) to identify. First, the location of radiation source is determined by the triangulation method, and then its spatial characteristic is collected by a band receiver array with simulation, which removes the limit...
Array jet dispensing technique plays an important role in micro assembly, especially for parts with different materials. An automatic array jet dispensing system was developed in this paper for micro inertial devices assembly. In order to have uniform original drop position of the adhesive array and easy monitoring, a machine vision module was integrated. The image processing and coordinate transformation...
Random array phase and range limitations are rigorously analyzed in a probabilistic sense using the mean value theorem. The elements of this model are assumed to form a uniformly distributed element population and are bounded to within a spherical volume. By this it is determined limitations in element location are not to exceed a tenth of a wavelength using a uniform distribution. Phase limitations...
On-orbit geometric calibration is a critical and essential step to guarantee the high geometric positioning accuracy of high-resolution optical satellite imagery. In this paper, we first review and summarize the on-orbit geometric calibration methods for high-resolution optical satellite and then analyze their advantages and disadvantages. Finally, we present our perspective on on-board geometric...
In this paper a direct method to estimate maximum power points (MPPs) in PV arrays subjected to mismatching conditions is presented. The method uses the lossless single-diode model (SDM) which is parameterized using the data of inflection and maximum power points of each panel. The reconstruction of power vs. voltage curve is obtained by one explicit equation, thus avoiding the use of recursive non-linear...
This work is related to unsupervised automatic speech segmentation. An experiment was carried out on the Frame Distance Array (FDA) algorithm with a main goal of the algorithm parameter tune-up. The experiment was carried out by applying the algorithm on TIMIT corpus and by using MFCC as the speech signal features. The parameters tuned up in this work are the frame length, the frame increment, the...
Identifying defects and classifying them according to some predefined classes is common in many manufacturing processes. The basis of such approach depends on a set of features extracted from all the classes and using them to train a classifier and then use it to determine the class to which the unseen data belongs to, with a reasonable accuracy. Hence the performance of the classifier depends on...
This paper describes proximity points approach for building recommendation systems. This approach is applicable for information systems which content (objects) is a semi-structured data with weak links. The described approach was used for implementing the "Open Karelia" recommendation system. The paper gives details about the proximity criterion selection and testing for specific domain...
In this paper we present some preliminary results on antenna array extrapolation for Direction Of Arrival (DOA) estimation using Sparse Reconstruction (SR). The objective of this study is to establish wether it is possible to achieve with an array of a given physical length the performance (in terms of accuracy, resolution and sidelobe level) of an equivalent larger array by using SR. The difference...
Three subclasses of geometries for nonuniform linear antenna arrays with a fixed number of sensors are compared in the sense of maximum possible direction-of-arrival (DOA) estimation accuracy. Cramer-Rao bound analysis is applied to compare the optimal accuracy for each geometry under some fixed source environment. Actual DOA estimation simulations, obtained by recently-introduced algorithms, are...
Large array size real time direction finding systems like phased array radars require very fast processing of signals. With subspace based array signal processing like MUltipleSIgnalClassification (MUSIC) algorithm high accuracy and resolution can be achieved if the data collection time is sufficiently large or the Signal to Noise Ratio (SNR) is adequately high. However high computational complexity...
A method for achieving super-resolution of sound field recording and reproduction is proposed. To obtain driving signals of loudspeakers for reproduction from received signals of microphones, sparse signal decomposition makes it possible to reduce spatial aliasing artifacts when the number of microphones is less than that of loudspeakers. For more accurate and robust signal decomposition, we propose...
Microphone array processing utilize spatial separation between the desired speaker and interference signal for speech enhancement. The transfer functions (TFs) relating the speaker component at a reference microphone with all other microphones, denoted as the relative TFs (RTFs), play an important role in beamforming design criteria such as minimum variance distortionless response (MVDR) and speech...
Recently, ESPRIT-based parameter estimation algorithms have been developed to exploit the structure of signals from strictly second-order (SO) non-circular (NC) sources. They achieve a higher estimation accuracy and can resolve up to twice as many sources. However, these NC methods assume that all the received signals are strictly non-circular. In this paper, we present the C-NC Standard ESPRIT and...
In this paper, we present a robust solution for data reduction in array processing. The purpose is to reduce the computation and improve the performance of applied signal processing algorithms by mapping the data into a lower-dimension beamspace through a transformation. Nulls steering to interference are incorporated into a transformation using the subspace projection technique, and the beamspace...
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