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Medium PRF set selection using evolutionary algorithms 总被引:2,自引:0,他引:2
This paper presents a new and novel method of selecting multiple pulse repetition frequency (PRF) sets for use in medium PRF pulsed-Doppler radars. Evolutionary algorithms are used to minimise the blind areas in the range/Doppler space. The evolutionary algorithm allows optimal solutions to be generated quickly, far faster than with exhaustive searches, and is fully automatic, unlike existing techniques. The evolved solutions compare very favorably against the results of both an exhaustive search and existing published PRF set selection methods. This evolutionary approach to generation of PRF sets is a major advance in medium PRF radar design. 相似文献
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Alabaster C.M. Hughes E.J. Matthew J.H. 《IEEE transactions on aerospace and electronic systems》2003,39(3):990-1001
Evolutionary algorithms are applied to the optimization of pulse repetition frequency (PRF), for both eight-and nine PRFs, in medium PRF radar while considering the detailed effects of sidelobe clutter and many other technical factors. The algorithm presented also ensures that all the solutions produced are fully decodable and have no blind velocities. The evolutionary algorithm was able to identify near-optimum PRF sets for a realistic radar system with only a modest computational effort. 相似文献
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Aya Bamba Hiroya Yamaguchi Katsuji Koyama Junko S. Hiraga Steve Holt John P. Hughes Hideaki Katagiri Jun Kataoka Satoru Katsuda Shunji Kitamoto Motohide Kokubun Hironori Matsumoto Emi Miyata Koji Mori Hiroshi Nakajima Masanobu Ozaki Rob Petre Akiko Sekiguchi Tadayuki Takahashi Takaaki Tanaka Yukikatsu Terada Hiroshi Tomida Yohko Tsuboi Masahiro Tsujimoto Hiroshi Tsunemi Yasunobu Uchiyama Masaru Ueno Shin Watanabe 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(3):411-415
SN 1006 is one of the supernova remnants (SNRs) with relatively low-temperature electrons, considering the young age of just 1000 years. We carried out SN 1006 mapping observations with the X-ray Imaging Spectrometers (XIS) and the Hard X-ray Detector (HXD) onboard Suzaku, the fifth Japanese X-ray satellite. Thanks to the excellent spectral resolution of XIS in the soft X-ray band, H-like and He-like oxygen emission lines were clearly detected, and we could make a map of the line intensity, and as well as a flux and the photon index of nonthermal component. We found that these parameters have spatial dependences from region to region in the SNR; the north region is bright in nonthermal, while dim in thermal; the east region is bright in both nonthermal and thermal; the inner region shows dim nonthermal and bright thermal emission. The photon index is the smallest in the north region. 相似文献
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Earp S.L. Hughes E.S. Elkins T.J. Vickers R. 《Aerospace and Electronic Systems Magazine, IEEE》1996,11(9):30-39
The suitability of ultra-wideband ground-penetrating radar as a tool for the detection of buried metallic mines is explored in this paper. The analysis centers around a 200-800 MHz, dual-polarized ground penetrating radar (GPR) designed and built by SRI International. The analysis consisted of fusing the images from the dual polarizations into a single image to enhance the target objects and suppress clutter. Results are shown for several variations of a Mahalanobis-based fusion technique, and “soft decision” minefield detection results based upon Monte Carlo statistical techniques are also presented. Although relatively few scenes were analyzed, these results show that the dual-polarized GPR is potentially very effective at finding buried mines and minefields 相似文献
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We analyzed tree rings in wood samples collected from some of the few surviving trees found close to the epicenter (within 4-5 km) of the Tunguska event that occurred on the last day of June 1908. Tree-ring growth shows a depression starting in the year after the event and continuing during a 4-5-year period. The most remarkable traces of the event were found in the rings' anatomical structure: (1) formation of "light" rings and a reduction of maximum density in 1908; (2) non-thickened tracheids (the cells that make up most of the wood volume) in the transition and latewood zones (the middle and last-formed parts of the ring, respectively); and (3) deformed tracheids, which are located on the 1908 annual ring outer boundary. In the majority of samples, normal earlywood and latewood tracheids were formed in all annual rings after 1908. The observed anomalies in wood anatomy suggest two main impacts of the Tunguska event on surviving trees--(1) defoliation and (2) direct mechanical stress on active xylem tissue. The mechanical stress needed to fell trees is less than the stress needed to cause the deformation of differentiating tracheids observed in trees close to the epicenter. In order to resolve this apparent contradiction, work is suggested on possible topographic modification of the overpressure experienced by these trees, as is an experimental test of the effects of such stresses on precisely analogous growing trees. 相似文献
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A High-Resolution Radar Detection Strategy 总被引:5,自引:0,他引:5
A comparison of single range cell detection and integrated contiguous range cell detection for a high range resolution radar is presented. A simulation was used to generate probability of detection curves for the two detection strategies using 10 target models with different target scattering characteristics. The integrated range cell detection strategy was found to be superior in all cases except when the target is composed of a single strong flare point. 相似文献
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M. A. Janssen J. E. Oswald S. T. Brown S. Gulkis S. M. Levin S. J. Bolton M. D. Allison S. K. Atreya D. Gautier A. P. Ingersoll J. I. Lunine G. S. Orton T. C. Owen P. G. Steffes V. Adumitroaie A. Bellotti L. A. Jewell C. Li L. Li S. Misra F. A. Oyafuso D. Santos-Costa E. Sarkissian R. Williamson J. K. Arballo A. Kitiyakara A. Ulloa-Severino J. C. Chen F. W. Maiwald A. S. Sahakian P. J. Pingree K. A. Lee A. S. Mazer R. Redick R. E. Hodges R. C. Hughes G. Bedrosian D. E. Dawson W. A. Hatch D. S. Russell N. F. Chamberlain M. S. Zawadski B. Khayatian B. R. Franklin H. A. Conley J. G. Kempenaar M. S. Loo E. T. Sunada V. Vorperion C. C. Wang 《Space Science Reviews》2017,213(1-4):139-185
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