ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system (open access)

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.
Date: March 5, 1992
Creator: Ramanathan, V. & Barnett, T.P.
System: The UNT Digital Library
Readily implemented enhanced sinusoid detection in noise (open access)

Readily implemented enhanced sinusoid detection in noise

Significant efforts have been devoted, spanning many years, to the problem of sinusoid detection in noise. Many of these efforts have produced superb, yet complex, algorithms which may be difficult to use for a wide segment of the Digital Signal Processing (DSP) community. This paper presents a simple, easily implemented and high effective method which solves this problem. This method severely degrades non-sinusoidal noise while leaving the embedded sinusoid(s) relatively undisturbed. The algorithm, simply put, exploits the difference between the net effect of integration and differentiation of sinusoids versus the effect of these operations on random noise and other signal sequences. The cross-correlation of sine wave with its differentiated (and/or integrated) self is quite high. Conversely, the cross-reduction of a noise sequence with its differentiated (and/or integrated) self is much lower. Therefore, it is reasonable to assume that for sequences consisting of a sinusoid in noise, significant signal-to-noise-ratios (SNRs) in the correlation results are achievable using a combination of differentiation (and/or integration) and cross-correlation operations on such sequences. This technique has been applied to actual Doppler radar data, as well as to synthesized data, with excellent improvement in signal detection capability. 4 refs.
Date: March 5, 1992
Creator: Lindsay, K.V.
System: The UNT Digital Library
Application of non-radiometric methods to the determination of plutonium. Literature review conducted for the Buried Waste Integrated Program (open access)

Application of non-radiometric methods to the determination of plutonium. Literature review conducted for the Buried Waste Integrated Program

This literature review was motivated by discussions that took place during a review of contamination control technologies proposed for INEL (buried waste). It should be a useful tool in identifying non-radiation measurement techniques for Pu and Am such as ICP-MS, which should fulfill the following criteria: apparatus must be field deployable; up to 100 samples per day; and lower levels of detection and required time must be listed. The sensitivity of ICP and RIMS is compared against that needed for contamination monitoring at INEL. Only Pu-241, with a required detection limit of 400 ppt, would challenge the sensitivity of ICP-MS; Pu-238 would be easily determined. The need to determine Pu-238 and Am-241 in the presence of U-238 and Pu-241 seems to preclude the possibility of using laser ablation ICP-MS for Pu monitoring. ICP-AES and -LEAFS methods may not have enough sensitivity to determine Pu-238 at 2 ppb level with confidence, but RIMS (resonance ionization mass spectroscopy) should be adequate. 47 refs, figs.
Date: March 5, 1992
Creator: Edelson, M. C.
System: The UNT Digital Library
ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system. Progress report, September 1, 1991--August 31, 1992 (open access)

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system. Progress report, September 1, 1991--August 31, 1992

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.
Date: March 5, 1992
Creator: Ramanathan, V. & Barnett, T. P.
System: The UNT Digital Library
Readily implemented enhanced sinusoid detection in noise (open access)

Readily implemented enhanced sinusoid detection in noise

Significant efforts have been devoted, spanning many years, to the problem of sinusoid detection in noise. Many of these efforts have produced superb, yet complex, algorithms which may be difficult to use for a wide segment of the Digital Signal Processing (DSP) community. This paper presents a simple, easily implemented and high effective method which solves this problem. This method severely degrades non-sinusoidal noise while leaving the embedded sinusoid(s) relatively undisturbed. The algorithm, simply put, exploits the difference between the net effect of integration and differentiation of sinusoids versus the effect of these operations on random noise and other signal sequences. The cross-correlation of sine wave with its differentiated (and/or integrated) self is quite high. Conversely, the cross-reduction of a noise sequence with its differentiated (and/or integrated) self is much lower. Therefore, it is reasonable to assume that for sequences consisting of a sinusoid in noise, significant signal-to-noise-ratios (SNRs) in the correlation results are achievable using a combination of differentiation (and/or integration) and cross-correlation operations on such sequences. This technique has been applied to actual Doppler radar data, as well as to synthesized data, with excellent improvement in signal detection capability. 4 refs.
Date: March 5, 1992
Creator: Lindsay, K. V.
System: The UNT Digital Library