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IEEE Transactions on Geoscience and Remote Sensing

Issue 3 • May 1991

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Displaying Results 1 - 15 of 15
  • Enhanced autoregressive moving average spectral estimation applied to the measurement of Doppler spectral width

    Publication Year: 1991, Page(s):358 - 368
    Cited by:  Papers (8)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    The measurement of clear-air turbulence with a Doppler radar is investigated. An autoregressive moving average (ARMA) model is proposed to improve the Doppler spectral width estimates. An iterative algorithm that has its origin in system identification is used for the estimation of the ARMA parameters. By taking advantage of a priori knowledge of the correlation matrix, which arises in the derivat... View full abstract»

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  • The derivative ratio algorithm: avoiding atmospheric effects in remote sensing

    Publication Year: 1991, Page(s):350 - 357
    Cited by:  Papers (46)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (676 KB)

    The author describes the development of the derivative ratio algorithm based on derivatives of a simple radiative transfer equation. The limiting conditions of the algorithm are derived and demonstrated using examples of reflectance spectra of turbid water and an ash leaf. For these example targets, the algorithm indicates that some spectral features do survive the trip through the atmosphere and ... View full abstract»

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  • Terrain influences in SAR backscatter and attempts to their correction

    Publication Year: 1991, Page(s):451 - 462
    Cited by:  Papers (42)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1584 KB)

    Synthetic aperture radar (SAR) images reveal radiometric image distortions that are caused by terrain undulations. The authors present the results of a study extracting and investigating the various components of these terrain influences. An imaging model, is set up for the geometric rectification of the SAR image and for a reconstruction of the imaging geometry. A prerequisite for the setup of th... View full abstract»

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  • Multibeam radar altimetry: spaceborne feasibility

    Publication Year: 1991, Page(s):465 - 469
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    An analysis of the inherent height and spatial resolution of an off-nadir radar altimeter is presented. For the general case, mean-square height uncertainty is shown to be proportional to the cross-track beamwidth divided by the along-track beamwidth. Thus, the cross-track beamwidth should be minimized and the along-track beamwidth maximized, subject to resolution and other constraints. A pure mul... View full abstract»

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  • The Danish SAR system: design and initial tests

    Publication Year: 1991, Page(s):417 - 426
    Cited by:  Papers (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1416 KB)

    In January 1986, the design of a high-resolution airborne C -band synthetic aperture radar (SAR) started at the Electromagnetics Institute of the Technical University of Denmark. The initial system test flights took place in November and December 1989. The authors describe the design of the system, its implementation, and its performance. They show how digital technology has been utilized... View full abstract»

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  • Polarimetric radar measurements of a forested area near Mt. Shasta

    Publication Year: 1991, Page(s):444 - 450
    Cited by:  Papers (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (700 KB)

    The authors present the results of an experiment using the NASA/JPL DC-8 AIRSAR (aircraft synthetic-aperture radar) over a coniferous forest near Mt. Shasta (California) in 1989. Calibration devices were deployed in clearings and under the forest canopy and passes at 20°, 40°, and 55° incidence angles were made with the AIRSAR. A total of eight images at differing incidence angles have... View full abstract»

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  • Synergic inversion technique for active and passive microwave remote sensing of the ocean

    Publication Year: 1991, Page(s):391 - 406
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1444 KB)

    A unified approach for combining active and passive microwave measurements for remote sensing applications is described. A synergic inversion technique has been developed and applied to the retrieval of geophysical parameters of the ocean surface and of the atmosphere. It is based on the combination of radiometric and radar measurements at the electromagnetic and cell level and not only on the cor... View full abstract»

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  • Head-banging: robust smoothing in the plane

    Publication Year: 1991, Page(s):369 - 378
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (768 KB)

    The head-banging technique is a median-based smoother intended for use on nongridded spatial data. The smoother is designed to remove small-scale local variations within a data set while preserving regional trends. Several synthetic and field data sets are used to test the performance of the technique. Head-banging is shown to be particularly adept at preserving edge structures and is thus applica... View full abstract»

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  • Estimation of ocean wave spectra using two-antenna SAR systems

    Publication Year: 1991, Page(s):463 - 465
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    Data from synthetic aperture radar, (SAR) systems can be used to estimate ocean wave directional spectra, but the method is limited by nonlinearities associated with the velocity bunching mechanism and the azimuth falloff effect, which reduces the range of azimuth wavelengths that can be observed. A theoretical analysis which suggests that the use of two or more receive antennas, spaced in the alo... View full abstract»

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  • Radiowave propagation in a coal seam with inhomogeneous rock walls

    Publication Year: 1991, Page(s):469 - 472
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    An idealized slab model of a horizontal coal seam is adopted. The structure is laterally uniform, but the media within and outside the slab are allowed to be inhomogeneous in the vertical direction. A general mode equation is obtained, and simplifications are made to facilitate computation of the propagation constant of the dominant mode. Using an exponential variation of the rock conductivity, it... View full abstract»

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  • Estimating splash pine biomass using radar backscatter

    Publication Year: 1991, Page(s):427 - 431
    Cited by:  Papers (47)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    L-band HV multiple-incidence-angle aircraft synthetic aperture radar (SAR) data were analyzed in relation to average stand biomass, basal area, and tree height for 55 slash pine plantations located in northern Florida. This information was used to develop a system of equations to predict average stand biomass as a function of L-band (24.5-cm) radar backscatter. The system of equa... View full abstract»

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  • Transform methods for seismic data compression

    Publication Year: 1991, Page(s):407 - 416
    Cited by:  Papers (23)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (684 KB)

    The authors consider the development and evaluation of transform coding algorithms for the storage of seismic signals. Transform coding algorithms are developed using the discrete Fourier transform (DFT), the discrete cosine transform (DCT), the Walsh-Hadamard transform (WHT), and the Karhunen-Loeve transform (KLT). These are evaluated and compared to a linear predictive coding algorithm for data ... View full abstract»

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  • Two-dimensional coherent noise suppression in seismic data using eigendecomposition

    Publication Year: 1991, Page(s):379 - 384
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (740 KB)

    A method for the suppression of coherent noise in seismic data based on the eigendecomposition of a data covariance matrix is demonstrated. Based on the Karhunen-Loeve transform, the proposed procedure is useful against noise energy exhibiting both two-dimensional space and time coherencies or coherent two-dimensional patterns which are not necessarily linear and therefore cannot generally be velo... View full abstract»

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  • A model for the imaging of urban areas by synthetic aperture radar

    Publication Year: 1991, Page(s):432 - 443
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1024 KB)

    A numerical model developed to simulate synthetic aperture radar images of urban targets is described. The model is based on ray tracing and is designed to simulate the effects of strong specular scatterers such as corner cubes as well as the diffuse scatter from the rough surfaces of buildings. The model uses a vectorial approach to the electromagnetic fields and so is able to simulate the polari... View full abstract»

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  • Doppler frequency estimation and the Cramer-Rao bound

    Publication Year: 1991, Page(s):385 - 390
    Cited by:  Papers (81)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB)

    Addresses the problem of Doppler frequency estimation in the presence of speckle and receiver noise. An ultimate accuracy bound for Doppler frequency estimation is derived from the Cramer-Rao inequality. It is shown that estimates based on the correlation of the signal power spectra with an arbitrary weighting function are approximately Gaussian-distributed. Their variance is derived in terms of t... View full abstract»

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Aims & Scope

 

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING (TGRS) is a monthly publication that focuses on the theory, concepts, and techniques of science and engineering as applied to sensing the land, oceans, atmosphere, and space; and the processing, interpretation, and dissemination of this information.

 

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Meet Our Editors

Editor-in-Chief
Antonio J. Plaza
University of Extremadura