The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

D.w. Hainsworth - One of the best experts on this subject based on the ideXlab platform.

  • Application of ground penetrating radar for coal Depth Measurement
    1999 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999
    Co-Authors: J.c. Ralston, D.w. Hainsworth
    Abstract:

    This paper describes the development of a new ground penetrating radar system for measuring coal thickness in underground mining operations. Although subsurface radar exhibits significant potential for Depth Measurement, the raw signals are complicated and cannot be readily interpreted by mining personnel. We show how real-time digital signal processing plays a key role in transforming the raw radar signals into a form that can be readily understood. We also indicate some of the unique challenges encountered when implementing a radar processing system in a harsh underground mining environment.

  • ICASSP - Application of ground penetrating radar for coal Depth Measurement
    1999 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999
    Co-Authors: J.c. Ralston, D.w. Hainsworth
    Abstract:

    This paper describes the development of a new ground penetrating radar system for measuring coal thickness in underground mining operations. Although subsurface radar exhibits significant potential for Depth Measurement, the raw signals are complicated and cannot be readily interpreted by mining personnel. We show how real-time digital signal processing plays a key role in transforming the raw radar signals into a form that can be readily understood. We also indicate some of the unique challenges encountered when implementing a radar processing system in a harsh underground mining environment.

A. Antoniou - One of the best experts on this subject based on the ideXlab platform.

  • A frequency-domain approach to shallow-water Depth Measurement
    IEEE Transactions on Geoscience and Remote Sensing, 1997
    Co-Authors: Radhakrishnan S. Pillai, A. Antoniou
    Abstract:

    A new formulation for ocean-Depth Measurement using a frequency-domain approach is proposed. This technique uses two high-resolution eigensubspace methods to estimate the ocean Depth from backscattered noisy data. The problem has been addressed both for real and complex attenuation coefficients by utilizing a double eigenstructure decomposition procedure on a Toeplitz as well as a Hankel matrix structure. The approach is similar to obtaining the best rational approximation that fits the actual measured data in a least-square sense.

  • Ocean-Depth Measurement: a frequency-domain approach
    IEEE Pacific Rim Conference on Communications Computers and Signal Processing. Proceedings, 1995
    Co-Authors: Radhakrishnan S. Pillai, A. Antoniou
    Abstract:

    A new formulation for ocean-Depth Measurement using the frequency-domain approach is proposed. This technique uses a high-resolution eigen subspace method to estimate the ocean-Depth from backscattered noisy data. The problem has been addressed for real attenuation coefficients by utilizing a eigenstructure decomposition procedure on a Toeplitz matrix structure.

T. Matsuyama - One of the best experts on this subject based on the ideXlab platform.

  • Depth Measurement by the multi-focus camera
    Proceedings. 1998 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (Cat. No.98CB36231), 1998
    Co-Authors: S. Hiura, T. Matsuyama
    Abstract:

    In this paper, we first introduce the multi-focus camera, a new image sensor used for Depth from defocus (DFD) range Measurement. It can capture three images with different focus values simultaneously. We then propose two different Depth Measurement methods using the camera. The first method, an augmented version of the one proposed by N. Asada et al. (1998), employs a noniterative optimization process to compute Depth values on edge points. The second one incorporates a coded aperture with the camera; and applies model-based pattern matching to estimate Depth values of textured surfaces. Here we propose two types of coded apertures and corresponding analysis algorithms: 1D Fourier analysis to acquire a Depth map and a blur-free image from three defocused images taken with a pair of pinholes, and 2D convolution based model matching for the fast and precise Depth Measurement using a coded aperture with four pinholes. Experimental results showed that the multi-focus camera works well as a practical DFD range sensor and that the coded apertures much improve its range estimation capability for real world scenes.

  • CVPR - Depth Measurement by the multi-focus camera
    Proceedings. 1998 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (Cat. No.98CB36231), 1998
    Co-Authors: S. Hiura, T. Matsuyama
    Abstract:

    In this paper, we first introduce the multi-focus camera, a new image sensor used for Depth from defocus (DFD) range Measurement. It can capture three images with different focus values simultaneously. We then propose two different Depth Measurement methods using the camera. The first method, an augmented version of the one proposed by N. Asada et al. (1998), employs a noniterative optimization process to compute Depth values on edge points. The second one incorporates a coded aperture with the camera; and applies model-based pattern matching to estimate Depth values of textured surfaces. Here we propose two types of coded apertures and corresponding analysis algorithms: 1D Fourier analysis to acquire a Depth map and a blur-free image from three defocused images taken with a pair of pinholes, and 2D convolution based model matching for the fast and precise Depth Measurement using a coded aperture with four pinholes. Experimental results showed that the multi-focus camera works well as a practical DFD range sensor and that the coded apertures much improve its range estimation capability for real world scenes.

Mikaela Taube - One of the best experts on this subject based on the ideXlab platform.

  • anterior chamber Depth Measurement a scan versus optical methods
    Journal of Cataract and Refractive Surgery, 2002
    Co-Authors: Gabor Koranyi, Eva Lydahl, Sverker Norrby, Mikaela Taube
    Abstract:

    Abstract Purpose: To evaluate methods of measuring anterior chamber Depth (ACD) before and after cataract surgery. Setting: St. Erik’s Eye Hospital, Stockholm, Sweden. Methods: A-scan (BVI Axis) and Scheimpflug imaging (Nidek EAS-1000) were used to measure ACD preoperatively and 6 and 18 weeks after phacoemulsification with implantation of a poly(methyl methacrylate) (PMMA) intraocular lens (IOL) in 23 patients. Because of a large systematic difference between the 2 methods, Measurement with Orbscan (Orbtek) and optical pachymetry (Haag-Streit) were included when Measurements were repeated 36 weeks postoperatively. A t test for paired observations was used for statistical analysis. Results: Preoperatively, the mean A-scan Measurements were significantly shorter than the Scheimpflug values: 3.05 mm ± 0.36 (SD) and 3.37 ± 0.35 mm, respectively (P Conclusions: There was good agreement between results obtained with 3 methods based on optical principles. Considering the basic and simple Measurement principle of these instruments, they appear to provide the correct result. The A-scan equipment used in this study is unsuitable for determination of ACD in eyes with PMMA IOLs.

J.c. Ralston - One of the best experts on this subject based on the ideXlab platform.

  • Application of ground penetrating radar for coal Depth Measurement
    1999 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999
    Co-Authors: J.c. Ralston, D.w. Hainsworth
    Abstract:

    This paper describes the development of a new ground penetrating radar system for measuring coal thickness in underground mining operations. Although subsurface radar exhibits significant potential for Depth Measurement, the raw signals are complicated and cannot be readily interpreted by mining personnel. We show how real-time digital signal processing plays a key role in transforming the raw radar signals into a form that can be readily understood. We also indicate some of the unique challenges encountered when implementing a radar processing system in a harsh underground mining environment.

  • ICASSP - Application of ground penetrating radar for coal Depth Measurement
    1999 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999
    Co-Authors: J.c. Ralston, D.w. Hainsworth
    Abstract:

    This paper describes the development of a new ground penetrating radar system for measuring coal thickness in underground mining operations. Although subsurface radar exhibits significant potential for Depth Measurement, the raw signals are complicated and cannot be readily interpreted by mining personnel. We show how real-time digital signal processing plays a key role in transforming the raw radar signals into a form that can be readily understood. We also indicate some of the unique challenges encountered when implementing a radar processing system in a harsh underground mining environment.