Examinando por Autor "Fernández Recio, R."

Mostrando 1 - 16 de 16

Acceso Abierto
Computational Burden Resulting from Image Recognition of High Resolution Radar Sensors
(Multidisciplinary Digital Publishing Institute (MDPI), 2013-04-22) López Rodríguez, P.; Fernández Recio, R.; Bravo, I.; Gardel, Alfredo; Lázaro, José L.; Rufo, Elena; Instituto Nacional de Técnica Aeroespacial (INTA)
This paper presents a methodology for high resolution radar image generation and automatic target recognition emphasizing the computational cost involved in the process. In order to obtain focused inverse synthetic aperture radar (ISAR) images certain signal processing algorithms must be applied to the information sensed by the radar. From actual data collected by radar the stages and algorithms needed to obtain ISAR images are revised, including high resolution range profile generation, motion compensation and ISAR formation. Target recognition is achieved by comparing the generated set of actual ISAR images with a database of ISAR images generated by electromagnetic software. High resolution radar image generation and target recognition processes are burdensome and time consuming, so to determine the most suitable implementation platform the analysis of the computational complexity is of great interest. To this end and since target identification must be completed in real time, computational burden of both processes the generation and comparison with a database is explained separately. Conclusions are drawn about implementation platforms and calculation efficiency in order to reduce time consumption in a possible future implementation.
Acceso Abierto
Evaluación de algoritmos de identificación no cooperativa de blancos aéreos mediante perfiles de alta resolución
(Ministerio de Defensa: Secretaria General Técnica, 2018-11-20) Hernán Vega, O.; López Rodríguez, P.; Escot Bocanegra, D.; Poyatos Martínez, D.; Fernández Recio, R.; Bravo, I.
El principal desafío tecnológico relacionado con la Seguridad y Defensa es la identificación de forma rápida y fiable de diferentes aeronaves en vuelo. La identificación no cooperativa de blancos aéreos basada en perfiles en distancia de alta resolución, permite conocer si un blanco es amigo o enemigo sin necesidad de establecer un enlace de comunicación con él. Este artículo presenta la simulación de un sistema de reconocimiento basado en la aplicación de la descomposición de valores singulares a un conjunto de perfiles sintéticos, para extraer sus características principales. Mediante esta técnica, cada blanco se modela como un subespacio, y de esta manera es posible trabajar con la información más significativa en el dominio transformado, reduciendo efectos no deseados como el ruido u otras posibles interferencias.
Restringido
Identificación no cooperativa de blancos reales aéreos mediante radar utilizando una base de datos sintética y descomposición en valores singulares
(Ministerio de Defensa: Secretaria General Técnica, 2013-11-07) López Rodríguez, P.; Fernández Recio, R.; Bravo, I.; De Diego Custodio, E.; Poyatos Martínez, D.; Escot Bocanegra, D.; Instituto Nacional de Técnica Aeroespacial (INTA)
El reconocimiento de blancos aéreos no cooperativos mediante perfiles de alta resolución es un procedimiento de gran interés en el ámbito de la defensa. La creación de la base de datos para el reconocimiento a partir de simulaciones electromagnéticas es un tema recursivo en el mundo de la identificación no cooperativa. Se trata de una solución de bajo coste que permite tener información de todos los posibles blancos, rangos de frecuencia y diferentes ángulos de aspecto. Sin embargo, el uso de simulaciones electromagnéticas como base de datos en el reconocimiento de aviones reales hace del proceso una tarea complicada. Mediante la descomposición en valores singulares de un conjunto de perfiles se consigue la reducción de dimensionalidad añadiendo la capacidad de trabajar en el dominio transformado para realizar el proceso de identificación. La principal dificultad de este estudio estriba en el reconocimiento de medidas reales con la utilización de una base de datos construida sintéticamente mediante simulaciones electromagnéticas de modelos CAD de aeronaves.
Restringido
Joint Direction of Arrival and amplitude estimation using Particle Swarm Optimization and a single snapshot
(Institute of Electrical and Electronics Engineers, 2010-05-09) Errasti Alcalá, B.; Escot Bocanegra, D.; Poyatos Martínez, D.; Jurado Lucena, A.; Fernández Recio, R.; Instituto Nacional de Técnica Aeroespacial (INTA)
Direction of Arrival (DOA) estimation is a problem which concerns very diverse fields of interest. In most applications, not only the DOA but also the estimation of the amplitude of the incoming signals is becoming an important issue. In that sense, Particle Swarm Optimization (PSO) has shown a great capability to solve the DOA problem accurately and this communication presents a method to estimate both the amplitude and the Direction of Arrival of several incoming signals of a given wavelength.
Restringido
Medida y Simulación de la Modulación Producida por el Movimiento de las Palas en la Dispersión Monoestática de una Cavidad
(Universidad Miguel Hernández de Elche, 2012-09-14) Uribe Pérez, N.; Escot Bocanegra, D.; Fernández Recio, R.; Poyatos Martínez, D.; Instituto Nacional de Técnica Aeroespacial (INTA)
The scattering behavior and simulation of cavities are still being studied by several research groups. In this paper, a simplified jet-engine model with eight straight blades and blade motion capability has been designed and manufactured at the National Institute for Aerospace Technology (INTA), Spain and the effect of the motion of the blades has been analyzed. The work carried out can be divided into two parts: measurements of the cavity in the anechoic chamber placed at INTA facilities, and simulations with HFSS, a commercial software for electromagnetic problems.
Restringido
Meta-Heuristic Approach for Single-Snapshot 2D-DOA and Frequency Estimation: Array Topologies and Performance Analysis [Wireless Corner]
(Institute of Electrical and Electronics Engineers, 2013-02-15) Errasti Alcalá, B.; Fernández Recio, R.; Instituto Nacional de Técnica Aeroespacial (INTA)
This paper presents a method that simultaneously estimates the two-dimensional (azimuth and elevation) direction of arrival (DOA) - along with the frequency - of a set of signals impinging on an array, with just a single snapshot. This methodology, an extension of a meta-heuristic approach for one-dimensional direction-of-arrival estimation, is valid for both uniform and nonuniform three-dimensional antenna arrays. In this paper, Particle Swarm Optimization (PSO) is used to test the validity of the method on several array topologies, although other optimization algorithms can also be applied. The performance analysis included simulations focused on the convergence, accuracy, resolution, and computational cost of the proposed methodology. A comparison of the numerical results with the Cramer-Rao bound is also included, in order to illustrate the accuracy.
Restringido
Methodology to Achieve Accurate Non Cooperative Target Identification Using High Resolution Radar and a Synthetic Database
(Springer Link, 2010-07-02) Jurado Lucena, A.; Errasti Alcalá, B.; Escot Bocanegra, D.; Fernández Recio, R.; Poyatos Martínez, D.; Montiel, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
In the last few years, there is a great interest in developing an identification system capable to make a reliable classification of aircrafts into different groups (friendly, hostile or neutral). Depending on the context in which these systems are deployed, incorrect identification may lead to serious problems, such as fratricide or engagement of civilian aircrafts. Different techniques have been researched to face this problem, but non-cooperative ones have awakened more interest because they do not require aircraft collaboration. Non Cooperative Target Identification (NCTI) using radar is a complex task, mainly due to the fact that a database of possible targets is needed. To populate this database, Radar Cross Section (RCS) predictions produced by computer simulation seem to be the most feasible way to perform this task, since measurements alone cannot cover the vast range of targets, configurations and required aspect angles. These predictions are typically performed in the frequency domain and a specific processing must be done to obtain both High Resolution Range Profiles (HRRPs) and 2D Inverse Synthetic Aperture Radar (2D-ISAR) images. This paper shows a methodology to face the NCTI task, which use both synthetic HRRPs and 2D-ISAR to achieve an accurate identification.
Acceso Abierto
New Benchmark Radar Targets for Scattering Analysis and Electromagnetic Software Validation
(The EM Academy, 2008-05-14) Escot Bocanegra, D.; Poyatos Martínez, D.; Fernández Recio, R.; Jurado Lucena, A.; Montiel, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
A validation process, in which simulations and measurements are compared, is necessary to have confidence in the results obtained by numerical methods that solve scattering problems. This paper presents Radar Cross Section (RCS) measurements of new targets suitable for electromagnetic software comparison and validation. These measurements can be used as an RCS reference data for testing existing and future codes, as well as for the analysis of the scattering mechanisms.
Acceso Abierto
Non-cooperative identification of civil aircraft using a generalised mutual subspace method
(The Institution of Engeering and Technology, 2016-01-01) López Rodríguez, P.; Escot Bocanegra, D.; Fernández Recio, R.; Bravo, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
The subspace-based methods are effectively applied to classify sets of feature vectors by modelling them as subspaces. However, their application to the field of non-cooperative target identification of flying aircraft is barely seen in the literature. In these methods, setting the subspace dimensionality is always an issue. Here, it is demonstrated that a modified mutual subspace method, which uses softweights to set the importance of each subspace basis, is a promising classifier for identifying sets of range profiles coming from real in-flight targets with no need to set the subspace dimensionality in advance. The assembly of a recognition database is also a challenging task. In this study, this database comprises predicted range profiles coming from electromagnetic simulations. Even though the predicted and actual profiles differ, the high recognition rates achieved reveal that the algorithm might be a good candidate for its application in an operational target recognition system.
Acceso Abierto
Non-Cooperative Target Recognition by Means of Singular Value Decomposition Applied to Radar High Resolution Range Profiles
(Multidisciplinary Digital Publishing Institute (MDPI), 2015-01-05) López Rodríguez, P.; Escot Bocanegra, D.; Fernández Recio, R.; Bravo, I.; Instituto Nacional de Técnica Aeroespacial (INTA); Agencia Estatal de Investigación (AEI)
Radar high resolution range profiles are widely used among the target recognition community for the detection and identification of flying targets. In this paper, singular value decomposition is applied to extract the relevant information and to model each aircraft as a subspace. The identification algorithm is based on angle between subspaces and takes place in a transformed domain. In order to have a wide database of radar signatures and evaluate the performance, simulated range profiles are used as the recognition database while the test samples comprise data of actual range profiles collected in a measurement campaign. Thanks to the modeling of aircraft as subspaces only the valuable information of each target is used in the recognition process. Thus, one of the main advantages of using singular value decomposition, is that it helps to overcome the notable dissimilarities found in the shape and signal-to-noise ratio between actual and simulated profiles due to their difference in nature. Despite these differences, the recognition rates obtained with the algorithm are quite promising.
Restringido
On the use of Particle Swarm Optimization for single snapshot DOA and frequency estimation
(Institute of Electrical and Electronics Engineers, 2012-05-31) Errasti Alcalá, B.; Fernández Recio, R.; Instituto Nacional de Técnica Aeroespacial (INTA)
Direction Of Arrival (DOA) estimation is a well known problem that has been studied through a wide range of different approaches and methods. Most of these methods make use of several snapshots in the array to provide an accurate result but their performance is commonly degraded when only a single snapshot is available. In a scenario where not only the DOAs are unknown but also the frequencies of the signals need to be estimated with a single snapshot is where heuristics show their potential. This communication presents the use of Particle Swarm Optimization (PSO) to estimate the DOA and the frequency of the incoming signals with a single snapshot. This enhanced methodology, applicable to both uniform and non-uniform arrays, can handle incoming signals with different complex amplitudes. Numerical results that show the validity of the approach are provided.
Restringido
Performance Analysis of Metaheuristic Approaches for Single-Snapshot DOA Estimation
(Institute of Electrical and Electronics Engineers, 2013-01-30) Errasti Alcalá, B.; Fernández Recio, R.; Instituto Nacional de Técnica Aeroespacial (INTA)
This letter addresses the application of metaheuristics to the single-snapshot direction-of-arrival estimation. The performances of five of the most popular optimization algorithms-Particle Swarm Optimization, Ant Colony Optimization for Continuous Domains, Simulated Annealing, Genetic Algorithms, and Differential Evolution-are compared in terms of convergence, accuracy, resolution, and computational cost in order to find the most suitable one. Also, running parameters are suggested for all of them. The featured numerical simulations include both uniform and nonuniform arrays and different noise scenarios. Results show that all of the presented optimization algorithms are capable of solving the problem, but Ant Colony Optimization for Continuous Domains is the most recommendable .
Restringido
RCS Analysis of a Configurable Mock-Up Cavity With Blade Motion Capability
(Institute of Electrical and Electronics Engineers, 2009-02-24) Poyatos Martínez, D.; Escot Bocanegra, D.; Fernández Recio, R.; Montiel Sánchez, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
The scattering behavior and simulation of cavities are still being studied by several research groups. In this paper, a simplified jet-engine model has been manufactured and measured under different configurations, such as straight or curved blades, different fixed blades position, and free motion capability at adjustable speed. These measurements can be used to analyze the response of cavities as well as radar cross-section reference data for validating existing and future prediction codes.
Acceso Abierto
Singular Value Decomposition Applied to Automatic Target Recognition with High Resolution Range Profiles
(Multidisciplinary Digital Publishing Institute (MDPI), 2014-01-02) López Rodríguez, P.; Escot Bocanegra, D.; Fernández Recio, R.; Bravo, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
Abstract: With the development of wideband radars new applications have emerged related to this kind of sensor. That is the case of automatic target recognition based on radar imagery. In this paper a target recognition methodology based on one dimensional high resolution radar imagery is presented. 1D radar images, namely high resolution range profiles (HRRP) are comprised of range bins and contain the distribution of the scattering centers of a target providing information about target structure. In this manuscript, identification of HRRP coming from measurements of in-flight aircraft is carried out by comparison with a database of simulated HRRPs. Simulated HRRPs have a very clean signature while actual HRRPs suffer from noise and other unwanted effects making the recognition process an arduous task. In order to overcome the differences between profiles, Singular Value Decomposition (SVD) is applied to matrices of HRRP. SVD is a robust tool for the decomposition of any matrix into orthogonal basis spaces, thus, by applying SVD to the HRRP matrices and selecting the most significant singular vectors, the matrices can be split into a signal and a noise subspace. The identification algorithm proposed in this paper is based on finding the aircraft which minimizes the angle between signal subspaces. Confusion matrices for the classification of the whole test set and error rates obtained will be provided in the paper full-version. As will be shown, the use of SVD provides good recognition rates even the lack of similarity between actual and simulated profiles.
Restringido
Study of the scattering mechanisms of a set of conospheres
(Institute of Electrical and Electronics Engineers, 2010-05-12) Fernández Recio, R.; Jurado Lucena, A.; Errasti Alcalá, B.; Escot Bocanegra, D.; Poyatos Martínez, D.; Instituto Nacional de Técnica Aeroespacial (INTA)
This paper presents Radar Cross Section (RCS) measurements and predictions of a set of three conospheres suitable for electromagnetic software validation. These measurements can be used as a RCS reference data for testing existing and future codes, as well as for the analysis of the scattering mechanisms present in this kind of objects. The association between the scattering mechanism and its response is specially valuable in a validation process, in which simulations and measurements are compared, to identify the possible weak points of the electromagnetic tool.
Acceso Abierto
Tendencias actuales de la lógica reconfigurable en sistema radar
(Universidad de Elche, 2012-09-19) López Rodríguez, P.; Fernández Recio, R.; Bravo, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
Los sistemas radar se caracterizan por la gran cantidad de procesamiento de señal que deben de llevar a cabo para la detección correcta de blancos en el espacio. Los dispositivos de lógica reconfigurable, por su estructura interna y velocidad son óptimos para su utilización en las diferentes etapas de estos sistemas. En este artículo se lleva a cabo un estudio del arte de la aplicación de la lógica reconfigurable en sistemas radar así como un posterior análisis de las etapas más críticas en las que ésta entra en juego.