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Wavelet-based speckle reduction in synthetic aperture radar images

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC science 1997年第9期80卷 29-36页

作者： Fukuda, S Hirosawa, H Inst. Space and Astronautical Sci. Sagamihara 229 Japan University of Tokyo Japan Inst. Space and Astronautical Sci. Japan Res. Div. for Spacecraft Engineering Inst. Space and Astronautical Sci. Japan Space VLBI Observ. Program Satellite Inst. of Space and Aero. Science University of Tokyo Japan IEICE Japan IEEE Remote Sensing Society United Kingdom

This paper proposes a wavelet-based approach to reducing speckle in synthetic aperture radar (SAR) images. The proposed approach, based on multiresolution analysis with a two-dimensional wavelet transform, aims at smoothing speckle without blurring edges. When an image is transformed by wavelets, edge information appears in detail images. The essence of the method is reducing the power of pixels without edge information in detailed images of each wavelet domain and reconstructing the image by inverse wavelet transform. This approach gives a high ability to smooth speckle and preserve edges in simulations and has been satisfactorily applied to real SAR images. (C) 1997 Scripta Technica, Inc.

关键词： SAR speckle reduction edge preservation multiresolution analysis two-dimensional wavelet transform

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Search for placer gold in eastern India - A geomorphological approach

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JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA 1996年第1期47卷 99-105页

作者： Chakrabarti, P State Remote Sensing Applic. Centre Dept. of Science and Technology NES Calcutta - 700 091 India

In eastern India, presence of gold is common both in alluvial and colluvial zones in a sporadic fashion over wide stretches of Purulia district, West Bengal and adjacent Singhbhum and Ranchi districts, Bihar. Regionally, the area is in between the Tamar - Porapahar shear zone in the north and the Dalma range in the south. Applied geomorphological studies, using remote sensing data products, with morphogenetic approach based on terrain analysis and classification help to outline such zones as manifestations of form process - material interactions. With this perspective, interpretation of satellite imagery (B & W, TM-FCC - LANDSAT) and aerial photographs has led to identification of relies of an 'Older planation surface' of Quaternary age in the Banduan area, Purulia district, West Bengal and Tamar - Ichagarh area, Ranchi and Singhbhum districts, Bihar. The different terrain units/sub-units, with placer gold concentration, associated with this 'Ranchi - Purulia Older planation surface' are degraded glacis, very degraded glacis, cone glacis. The 'degraded glacis' with latosol/laterite crust (nodular ferricrete only) could be used as a guide horizon for preliminary search of placer 'gold in laterite' or 'lateritic gold' as has been reported from Brazil, Australia, West Africa and some Gulf countries in a similar set up.

关键词： placer gold economic geology geomorphology Bihar West Bengal

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Mapping evapotranspiration and water balance for global land surfaces

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ISPRS JOURNAL OF PHOTOGRAMMETRY AND remote sensing 1996年第4期51卷 209-215页

作者： Tateishi, R Ahn, CH Center for Environmental Remote Sensing Chiba University 1-33 Yayoi-cho Inage-ku Chiba City 263 Japan Systems Engineering Research Institute Korea Institute of Science and Technology Euendong 1 Yoosung-gu Taejeon 305-333 Korea

Evapotranspiration returns approximately 60-80% of precipitation back to the atmosphere, where it becomes the source of future precipitation. Any variations in the distribution and availability of surface water will affect human activities and undoubtedly result in some socio-economic adjustments. New water demands for irrigation, as well as non-agricultural purposes, are growing with increased population and industrialization. It is reasonable to conclude that our knowledge of broad-scale evapotranspiration patterns is incomplete and that improved data sets are needed. Therefore, in this study, monthly global data sets of evapotranspiration and water balance were produced using a simplified water balance model and published global data sets. For validation of the global data sets, results were compared with information obtained by previous investigations that used independent data and analytical approaches.

关键词： Geographic information systems

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Energy representation based multiscale approach to image texture

Energy representation based multiscale approach to image tex...

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3rd International Conference on Signal Processing (ICSP 96)

作者： Zhang, JX Li, DR Liu, J Institute of Image Recognition & AI Huazhong University of Science and Technology Wuhan Hubei China School of Remote Sensing and Informatics Wuhan Technical University of Surveying and Mapping Wuhan Hubei China

ISBN: (纸本)7505338900

It is important to consider the role of scale for texture analysis since its multiscale attribute of image texture. In this paper a textural detector based on 2D Gabor function and visual textural perception is established first then based on the textural detector and recent developed theory of time-scale space decomposition-a general class extending wavelet transform, an energy distribution based texture anal sis method is proposedx. The texture analysis technique gives textural energy representation between spatial space and scale space and provides a hierarchical analysis framework for Image texture. They can detect different scale texture features correspond to the visual texture perception and have the ability to recognize texture image effectively.

关键词： texture feature fusion texture analysis gabor function multiscale decomposition time-scale distribution

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Results of the experiments using synthetic aperture radar onboard the European remote sensing satellite 1 - 2. Radiometric calibration

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Journal of the Communications Research Laboratory 1996年第3期43卷 299-312页

作者： Fujita, Masaharu Fujino, Yoshiyuki Hanado, Hiroshi Ochiai, Satoshi Satake, Makoto Horie, Hiroaki Sato, Kenji Antenna and Device Section Electromagnetic Technology Division Microwave Remote Sensing Earth Observation Technology Section Radar Remote Sensing Millimeter-wave Remote Sensing Sect. Global Environment Division Microwave Remote Sensing Okinawa Radiowave Observatory Radar Remote Sensing Antenna and Device Section Electromagnetic Technology Division Nemerical Des. Antenna Microwave P. Millimeter-wave Remote Sensing Sect. Global Environment Division Millimeterwave Atmospheric Science Earth Observation Technology Section Microwave Remote Sensing

A radiometric calibration experiment is carried out by using square trihedrals for NASDA standard products (level 2.1 products) of ERS-1 SAR. The relation between the image data number and the radar cross section is established through the evaluation of the trihedral images. Spatial resolution is measured from a spread of trihedral images and is used to derive the backscattering coefficient of a target from its radar cross section. In addition, a novel active radar calibrator (ARC) with a function for introducing frequency shift is developed and it is demonstrated that the ERS-1 SAR image of the ARC moves in the azimuth direction in proportion to the amount of frequency shift and its distance agrees with a theoretical prediction.

关键词： Synthetic aperture radar

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ENERGY REPRESENTATION BASED MULTISCALE APPROACH TO IMAGE TEXTURE

ENERGY REPRESENTATION BASED MULTISCALE APPROACH TO IMAGE TEX...

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1996 3rd International Conference on Signal Processing(ICSP’96)

作者： Zhang Jixian Li Deren Liu Jian Institute of Image Recognition & AI Huazhong University of Science and Technology School of Remote Sensing and Informatics Wuhan Technical University of Surveying and Mapping

It is important to consider the role of scale for texture analysis since its multiscale attribute of image tex *** this paper,a textural detector based on 2D Gabor function and visual textural perception is established *** based on the textural detector and recent developed theory of time-scale space decomposition-a general class extending wavelet *** energy distribution based multiscale texture analysis method is *** multiscale texture analysis technique gives textural energy representation between spatial space and scale *** provides a hierarchical analysis framework for image *** can detect different scale texture features,correspond to the visual texture perception,and have the ability to recognize texture image effectively.

关键词： Texture Feature Fusion Texture Analysis Gabor Function Multiscale Decomposition Time-scale Distribution

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Tropical cyclone satellite remote sensing 34th

Tropical cyclone satellite remote sensing

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34th Aerospace sciences Meeting and Exhibit, 1996

作者： Hawkins, Jeffrey D. Richardson, Kim Turk, Joe Velden, Chris Poe, Gene Helveston, Marla Naval Research Laboratory Marine Meteorology Division MontereyCA93943 United States Space Science and Engineering Center University of Wisconsin MadisonWI53706 United States Naval Research Laboratory Remote Sensing Division WashingtonDC20375 United States Analysis and Technology Inc 321 Shieldsboro Square Bay St. LouisMS39520 United States

Current operational methods to detail the location, structure and intensity of tropical cyclones around the globe rely largely on the manual interpretation of visible and infrared imagery along with the sparse conventional observations. The inclusion of passive microwave imagery from the Special Sensor Microwave/Imager (SSM/I), high resolution cloud and water vapor tracked winds from geostationary satellite imagery and scatterometer derived ocean surface wind vectors can significantly assist the tropical cyclone analysts and forecasters map the current storm environment. SSM/I images and derived products (e.g., surface wind speed, rainrate, total precipitable water, cloud liquid water) provide a wealth of new information on surface and rainband conditions. This is essential since high clouds may obscure low level features within visible and infrared imagery. Cloud and water vapor tracked winds from sequential geostationary imagery can also provide low, middle and upper level winds and identify key meteorological phenomena that may impact future storm track or intensity changes (e.g., shear, upper level lows, ridging). Each additional piece of satellite derived information can improve the resulting warnings and forecasts. © 1996, American Institute of Aeronautics and Astronautics, Inc.

关键词： Tropical cyclone

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A method of moments model for VHF propagation

A method of moments model for VHF propagation

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Antennas and Propagation Society International Symposium

作者： J.T. Johnson R.T. Shin J. Eidson L. Tsang J.A. Kong Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Lincoln Laboratory MIT Lexington MA USA Electromagnetics and Remote Sensing Laboratory University of Washington Seattle WA USA

Site specific VHF propagation models remain a subject of continuing interest. A number of approximate methods exist and have been applied successfully in specific cases, but the limitations of the approximations of these models remain unclear. A numerically exact model based on the banded matrix iterative approach (BMIA) to the method of moments is presented which enables the solution of practical propagation problems. Although this model remains computationally complex, use of the iterative method along with parallel computing techniques enables large scale propagation problems to be solved within reasonable amounts of computational time. A typical VHF propagation problem involves predicting the power measured by a receiver as a function of altitude at a given distance away from a like polarised transmitter and above an inhomogeneous terrain profile.

关键词： Moment methods Iterative methods Concurrent computing Numerical models Computational modeling Parallel processing Large-scale systems Power measurement Polarization Transmitters

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The Navstar global positioning system in operation desert storm: A research note

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Intelligence and National Security 1995年第2期10卷 327-335页

作者： Michael Russell Rip David P. Lusch Assistant Professor in the Department of Geography (College of Social Science) Michigan State University Program in Epidemiology (College of Human Medicine) Michigan State University Research Specialist in the Center for Remote Sensing Michigan State University

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remote sensing of current-wave interactions with SIR-C/X-SAR during SRL-1 and SRL-2 at the Gulf Stream Supersite

Remote sensing of current-wave interactions with SIR-C/X-SAR...

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IEEE International Symposium on Geoscience and remote sensing (IGARSS)

作者： S.A. Mango S.R. Chubb F. Askari J.S. Lee G.R. Valenzuela R.W. Jansen R.A. Fusina B. Holt R.M. Goldstein W. Alpers T.F. Donato M.R. Grunes H.H. Shih J. Verdi J.C. Church L.K. Shay Remote Sensing Division Naval Research Laboratory Inc. Washington D.C. DC USA Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA University of Hamburg Hamburg Germany Allied Signal Corporation Columbia MD USA National Oceanic and Atmospheric Administration NOS Silver Spring MD USA Naval Air Warfare Center Warminster PA USA Marine Geosciences Division Stennis Space Center Naval Research Laboratory Inc. MS USA Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA

The Shuttle Imaging Radar, (SIR)-C/X-SAR, first and second Shuttle Radar Laboratory (SRL) missions, SRL-1 and SRL-2, took place April 9-20 and Sept. 30-Oct. 10, 1994. The authors report on a major, multi organizational series of experiments designed to investigate oceanographic phenomena at the Gulf Stream (GS) Supersite off the east coast of the US during these two missions. The investigations emphasized current-wave and air-sea interactions with extensive ground/sea/air truthing. The authors summarize a number of detailed findings associated with SRL-1 and provide a preliminary description of SRL-2 results.

关键词： remote sensing Spaceborne radar Radar imaging Sea measurements Airborne radar Current measurement Laboratories Oceans Synthetic aperture radar Radar polarimetry

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