The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform
David S. Citrin - One of the best experts on this subject based on the ideXlab platform.
-
Terahertz deconvolution based on autoregressive spectral extrapolation
2017 42nd International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:A novel terahertz (THz) deconvolution technique based on the autoregressive (AR) spectral extrapolation is presented in this study. An autoregressive process is modeled based on the THz frequency components with high signal-to-noise ratio, and the missing frequency components in regions with low signal-to-noise ratio are extrapolated based on the autoregressive model. In this way, the entire THz frequency spectrum of the Impulse Response function is estimated. This method is able to provide a ‘quasi-Ideal’ Impulse Response function, and therefore, significantly enhances the depth-resolution for resolving optically thin layers in the THz regime.
-
Depth resolution enhancement of terahertz deconvolution by autoregressive spectral extrapolation
Optics Letters, 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:This Letter presents a method for enhancing the depth resolution of terahertz deconvolution based on autoregressive (AR) spectral extrapolation. The terahertz frequency components with a high signal-to-noise ratio (SNR) are modeled with an AR process, and the missing frequency components in the regions with low SNRs are extrapolated based on the AR model. In this way, the entire terahertz frequency spectrum of the Impulse Response function, corresponding to the material structure, is recovered. This method, which is verified numerically and experimentally, is able to provide a “quasi-Ideal” Impulse Response function and, therefore, greatly enhances the depth resolution for characterizing optically thin layers in the terahertz regime.
Lars M. Wells - One of the best experts on this subject based on the ideXlab platform.
-
A portfolio of fine-resolution SAR images
Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII, 2004Co-Authors: Armin W. Doerry, Vivian Dee Gutierrez, Lars M. WellsAbstract:Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming high-quality exceptionally fine resolution images. Resolutions as fine as 4 inches (10 cm) in both slant range and azimuth are routinely formed in real time on board Sandia’s DeHavilland DHC-6 Twin Otter aircraft using a Ku-band SAR. Resolutions as fine as 6 inches (15 cm) in both slant range and azimuth are routinely formed using an X-band SAR. Careful system design allows high image quality as measured by nearly Ideal Impulse Response (IPR) shapes, with typical Multiplicative Noise Ratios (MNR) of better than 20 dB, and a noise equivalent reflectivity usually better than -30 dB. Collection geometries routinely include squint angles 45 degrees both fore and aft of broadside, on either side of the aircraft. This paper offers a collection of high quality images representative of the output of Sandia’s testbed radar. High-quality fine-resolution images of a variety of target scenes will be displayed, with annotation describing relevant image parameters.
-
A portfolio of fine-resolution SAR images: continued
Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII, 2004Co-Authors: Armin W. Doerry, Vivian Dee Gutierrez, Lars M. WellsAbstract:Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming high-quality exceptionally fine resolution real-time images. Resolutions as fine as 4 inches (10 cm) in both slant range and azimuth are routinely formed in real time on board Sandia’s DeHavilland DHC-6 Twin Otter aircraft using a Ku-band SAR. Resolutions as fine as 6 inches (15 cm) in both slant range and azimuth are routinely formed using an X-band SAR. Careful system design allows high image quality as measured by nearly Ideal Impulse Response (IPR) shapes, with typical Multiplicative Noise Ratios (MNR) of better than 20 dB, and a noise equivalent reflectivity usually better than -30 dB. Collection geometries routinely include squint angles 45 degrees both fore and aft of broadside, on either side of the aircraft. This paper offers a collection of high quality images representative of the output of Sandia’s testbed radar. High-quality fine-resolution images of a variety of target scenes will be displayed, with annotation describing relevant image parameters. This paper is the second of a set of two portfolios.
Junliang Dong - One of the best experts on this subject based on the ideXlab platform.
-
Terahertz deconvolution based on autoregressive spectral extrapolation
2017 42nd International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:A novel terahertz (THz) deconvolution technique based on the autoregressive (AR) spectral extrapolation is presented in this study. An autoregressive process is modeled based on the THz frequency components with high signal-to-noise ratio, and the missing frequency components in regions with low signal-to-noise ratio are extrapolated based on the autoregressive model. In this way, the entire THz frequency spectrum of the Impulse Response function is estimated. This method is able to provide a ‘quasi-Ideal’ Impulse Response function, and therefore, significantly enhances the depth-resolution for resolving optically thin layers in the THz regime.
-
Depth resolution enhancement of terahertz deconvolution by autoregressive spectral extrapolation
Optics Letters, 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:This Letter presents a method for enhancing the depth resolution of terahertz deconvolution based on autoregressive (AR) spectral extrapolation. The terahertz frequency components with a high signal-to-noise ratio (SNR) are modeled with an AR process, and the missing frequency components in the regions with low SNRs are extrapolated based on the AR model. In this way, the entire terahertz frequency spectrum of the Impulse Response function, corresponding to the material structure, is recovered. This method, which is verified numerically and experimentally, is able to provide a “quasi-Ideal” Impulse Response function and, therefore, greatly enhances the depth resolution for characterizing optically thin layers in the terahertz regime.
Alexandre Locquet - One of the best experts on this subject based on the ideXlab platform.
-
Terahertz deconvolution based on autoregressive spectral extrapolation
2017 42nd International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:A novel terahertz (THz) deconvolution technique based on the autoregressive (AR) spectral extrapolation is presented in this study. An autoregressive process is modeled based on the THz frequency components with high signal-to-noise ratio, and the missing frequency components in regions with low signal-to-noise ratio are extrapolated based on the autoregressive model. In this way, the entire THz frequency spectrum of the Impulse Response function is estimated. This method is able to provide a ‘quasi-Ideal’ Impulse Response function, and therefore, significantly enhances the depth-resolution for resolving optically thin layers in the THz regime.
-
Depth resolution enhancement of terahertz deconvolution by autoregressive spectral extrapolation
Optics Letters, 2017Co-Authors: Junliang Dong, Alexandre Locquet, David S. CitrinAbstract:This Letter presents a method for enhancing the depth resolution of terahertz deconvolution based on autoregressive (AR) spectral extrapolation. The terahertz frequency components with a high signal-to-noise ratio (SNR) are modeled with an AR process, and the missing frequency components in the regions with low SNRs are extrapolated based on the AR model. In this way, the entire terahertz frequency spectrum of the Impulse Response function, corresponding to the material structure, is recovered. This method, which is verified numerically and experimentally, is able to provide a “quasi-Ideal” Impulse Response function and, therefore, greatly enhances the depth resolution for characterizing optically thin layers in the terahertz regime.
Armin W. Doerry - One of the best experts on this subject based on the ideXlab platform.
-
A portfolio of fine-resolution SAR images
Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII, 2004Co-Authors: Armin W. Doerry, Vivian Dee Gutierrez, Lars M. WellsAbstract:Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming high-quality exceptionally fine resolution images. Resolutions as fine as 4 inches (10 cm) in both slant range and azimuth are routinely formed in real time on board Sandia’s DeHavilland DHC-6 Twin Otter aircraft using a Ku-band SAR. Resolutions as fine as 6 inches (15 cm) in both slant range and azimuth are routinely formed using an X-band SAR. Careful system design allows high image quality as measured by nearly Ideal Impulse Response (IPR) shapes, with typical Multiplicative Noise Ratios (MNR) of better than 20 dB, and a noise equivalent reflectivity usually better than -30 dB. Collection geometries routinely include squint angles 45 degrees both fore and aft of broadside, on either side of the aircraft. This paper offers a collection of high quality images representative of the output of Sandia’s testbed radar. High-quality fine-resolution images of a variety of target scenes will be displayed, with annotation describing relevant image parameters.
-
A portfolio of fine-resolution SAR images: continued
Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII, 2004Co-Authors: Armin W. Doerry, Vivian Dee Gutierrez, Lars M. WellsAbstract:Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming high-quality exceptionally fine resolution real-time images. Resolutions as fine as 4 inches (10 cm) in both slant range and azimuth are routinely formed in real time on board Sandia’s DeHavilland DHC-6 Twin Otter aircraft using a Ku-band SAR. Resolutions as fine as 6 inches (15 cm) in both slant range and azimuth are routinely formed using an X-band SAR. Careful system design allows high image quality as measured by nearly Ideal Impulse Response (IPR) shapes, with typical Multiplicative Noise Ratios (MNR) of better than 20 dB, and a noise equivalent reflectivity usually better than -30 dB. Collection geometries routinely include squint angles 45 degrees both fore and aft of broadside, on either side of the aircraft. This paper offers a collection of high quality images representative of the output of Sandia’s testbed radar. High-quality fine-resolution images of a variety of target scenes will be displayed, with annotation describing relevant image parameters. This paper is the second of a set of two portfolios.
