The distortion moment spectrum of 28SiH4: The microwave Q branch

1976 ◽  
Vol 54 (11) ◽  
pp. 1094-1105 ◽  
Author(s):  
I. Ozier ◽  
R. M. Lees ◽  
M. C. L. Gerry
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Double Resonance ◽  
Rotational Constant ◽  
The Absolute ◽  
Standard Deviations

Eleven pure rotational Q-branch transitions have been observed between 8 and 25 GHz in the distortion moment spectrum of 28SiH4. The spectrometer used was a conventional Stark-modulated instrument modified to have a sensitivity of ~1 × 10−11 cm−1. From the eleven frequencies, values have been determined for the single quartic tensor distortion constant DT, the two sextic constants H4T and H6T, and the three octic constants L4T, H6T, and L8T. These are (in Hz): DT = (74 751.4 ± 1.6); H4T = −(6.044 ± 0.010); H6T = (2.598 ± 0.003); L4T = (46.5 ± 1.5) × 10−5; L6T = −(37.9 ± 0.8) × 10−5; L8T = −(76.6 ± 2.1) × 10−5. The errors here are the standard deviations obtained from a least squares analysis; estimates are also given of the absolute errors. For possible application in other high resolution studies of silane, the constants have been used to calculate all Q-branch splittings for J ≤ 20. The present results are compared to those obtained by double resonance methods by Kreiner and Oka; a definite identification has been found for one of their lines which had previously been tentatively assigned to another transition. The combination-differences data of Pierre, Guelachvili, and Amiot have been reanalysed on the basis of the current results to obtain improved values of the rotational constant and the quartic and sextic scalar distortion constants.

The distortion moment spectrum of GeH4: the microwave Q branch

1979 ◽  
Vol 57 (4) ◽  
pp. 593-600 ◽  
Author(s):  
R. H. Kagann ◽  
I. Ozier ◽  
G. A. McRae ◽  
M. C. L. Gerry
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Double Resonance ◽  
Complete Analysis ◽  
Resonance Spectroscopy ◽  
Centrifugal Distortion ◽  
Double Resonance Spectroscopy ◽  
The Absolute ◽  
Centrifugal Distortion Constants ◽  
Single Set

Ten pure rotational Q-branch transitions of the distortion moment spectrum of GeH4 have been measured between 9 and 23 GHz. They were observed in a conventional Stark modulated spectrometer modified to have a sensitivity of 1 × 10−11 cm−1. No Ge isotope splitting was observed in the spectrum. The spectrum was analysed in terms of a single set of six tensor centrifugal distortion constants DT, H4T, H6T, L4T, L6T, and L8T. The results were found to predict accurately transitions previously reported from infrared–microwave double resonance spectroscopy, and a complete analysis using both sets of data was carried out. The results are (in hertz): DT = 67 775.54 ± 0.86; H4T = −5.3827 ± 0.0055; H6T = 2.9693 ± 0.0019; L4T = (3.996 ± 0.088) × 10−4; L6T = −(4.122 ± 0.050) × 10−4; L8T = −(8.01 ± 0.14) × 10−4. The errors here are the standard deviations obtained from the least-squares analysis; estimates of the absolute errors are also given. For possible application in other high resolution studies, the constants have been used to calculate all tensor splittings for J ≤ 20.

The Distortion Moment Microwave Spectrum of 12CH4 in the Ground Vibronic State

1975 ◽  
Vol 53 (19) ◽  
pp. 1791-1805 ◽  
Author(s):  
C. W. Holt ◽  
M. C. L. Gerry ◽  
I. Ozier
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Double Resonance ◽  
Microwave Spectrum ◽  
Experimental Techniques ◽  
Rotational Spectrum ◽  
Vibronic State ◽  
Microwave Spectrometer ◽  
The One ◽  
Theoretical Considerations

Seven Q branch transitions between 7.8 and 20 GHz have been observed in the distortion moment pure rotational spectrum of 12CH4 in its ground vibronic state. The spectrum was obtained using a conventional Stark modulated microwave spectrometer specially modified for the detection of very weak lines. From the frequencies of these seven transitions, along with the ortho–para splitting known for the (J = 2) state and two Q branch splittings measured earlier by infrared–microwave double resonance, we have determined the one quartic tensor distortion constant DT, the two sextic constants H4T and H6T, and the three octic constants L4T, L6T, and L8T. These are (in Hz): DT = (132 943.41 ± 0.71); H4T = −(16.9839 ± 0.0076); H6T = (11.0342 ± 0.0086); L4T = (20.27 ± 0.24) × 10−4; L6T = −(26.77 ± 0.35) × 10−4; L8T = −(30.0 ± 1.8) × 10−4. The errors are the standard deviations resulting from a least squares analysis. Estimates are also given of the absolute errors. These results consitute the first measurement of the octic distortion constants. The values for DT, H4T, and H6T are compared to earlier determinations. The theoretical considerations that affect the observation of these transitions are reviewed and a detailed description of the special experimental techniques used is given. The method of analysis is described. Finally, as an aid to other high resolution studies of methane and to possible astrophysical detection of the molecule, the Q branch splittings are tabulated up to J = 21.

scholarly journals Direkte Bestimmung des absoluten Vorzeichens des Triplett- Nullfeld-Parameters D mit hochauflösender optischer Detektion von ESR / Direct Determination of the Absolute Sign of the Triplet Zero Field Parameter D by High Resolution Optical Detection of ESR

1974 ◽  
Vol 29 (11) ◽  
pp. 1543-1547 ◽  
Author(s):  
H. Schuch ◽  
F. Seiff ◽  
R. Furrer ◽  
K. Möbius ◽  
K. P. Dinse
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Triplet State ◽  
Optical Detection ◽  
Double Resonance ◽  
Direct Determination ◽  
Resonance Method ◽  
Optical Methods ◽  
Zero Field ◽  
The Absolute

The electronic triplet state sublevels of aromatic molecules generally have different energies already at zero external magnetic field. This zero field splitting usually is too small to be resolved by a high resolution optical spectrometer, and only a high magnetic field (typically 30 kG) yields enough Zeeman-splitting to allow full resolution. From the Zeeman pattern one can extract the absolute sign of the triplet parameter D, which probes the electronic wavefunction of the triplet state.Compared with purely optical methods with their inherent lack of resolution, we demonstrate that a double resonance method yields the sign of D even in relatively small magnetic fields due to the improved optical resolution.This double resonance method is a modification of Optical Detection of ESR (ODMR). Now the sign determination seems to be a routine procedure.

Iterative least-squares migration for high-resolution angle gathers

2020 ◽  
Author(s):  
Lian Duan ◽  
Alejandro Valenciano ◽  
Nizar Chemingui
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Least Squares Migration

Least‐squares inversion of in‐situ sonic Q measurements: Stability and resolution

Geophysics ◽  
2004 ◽  
Vol 69 (2) ◽  
pp. 378-385 ◽  
Author(s):  
Aristotelis Dasios ◽  
Clive McCann ◽  
Timothy Astin
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Instantaneous Frequency ◽  
Spectral Ratio ◽  
Full Waveform ◽  
Multiple Measurements ◽  
Sandstone Reservoir ◽  
Gas Bearing

We minimize the effect of noise and increase both the reliability and the resolution of attenuation estimates obtained from multireceiver full‐waveform sonics. Multiple measurements of effective attenuation were generated from full‐waveform sonic data recorded by an eight‐receiver sonic tool in a gas‐bearing sandstone reservoir using two independent techniques: the logarithmic spectral ratio (LSR) and the instantaneous frequency (IF) method. After rejecting unstable estimates [receiver separation <2 ft (0.61 m)], least‐squares inversion was used to combine the multiple estimates into high‐resolution attenuation logs. The procedure was applied to raw attenuation data obtained with both the LSR and IF methods, and the resulting logs showed that the attenuation estimates obtained for the maximum receiver separation of 3.5 ft (1.07 m) provide a smoothed approximation of the high‐resolution measurements. The approximation is better for the IF method, with the normalized crosscorrelation factor between the low‐ and high‐resolution logs being 0.90 for the IF method and 0.88 for the LSR method.

A Ground-Motion Prediction Equation for the Western and the Southwestern Parts of China Based on Local Strong-Motion Records and an Overseas Reference Model for the Vertical Component

2021 ◽  
Author(s):  
Hao Xing ◽  
John X. Zhao
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Reference Model ◽  
Prediction Equation ◽  
Motion Prediction ◽  
Ground Motion Prediction Equation ◽  
Ground Motion Prediction ◽  
Magnitude Scaling ◽  
The Absolute ◽  
Standard Deviations

ABSTRACT A ground-motion prediction equation for the vertical ground motions from the western and the southwestern parts of China (referred to as SWC) is presented in this study. Based on the Xing and Zhao (2021) study, the Zhao et al. (2017) model (referred to as ZHAO2017) for the shallow crustal earthquakes in Japan was used as the reference model. We used a bilinear magnitude-scaling function hinged at a moment magnitude (Mw) of 7.1. The magnitude-scaling rate for events with Mw&gt;7.1 was determined by records from the SWC dataset and the large events in the Pacific Earthquake Engineering Research Center Next Generation Attenuation-West2 dataset. Site classes (SCs) were used as the site response proxy. All other parameters were derived from the SWC dataset only. The magnitude-scaling rates for events with Mw≤7.1 in this study are larger than in the ZHAO2017 model at most periods. The absolute values of the geometric attenuation rates are larger, and the absolute values of the anelastic attenuation rates are smaller than in the ZHAO2017 model. The between-event standard deviations are smaller than in the ZHAO2017 model at short periods, and the within-event standard deviations are larger than in the ZHAO2017 model at all periods. The differences in the between-site standard deviations vary significantly from one SC to another. We also find that the between-event and within-event residuals are almost independent of magnitude and source distance. The response spectrum attenuates less rapidly than in the ZHAO2017 model at distances less than 30 km.

scholarly journals A High-Resolution Gravimetric Geoid Model for Kuwait Using the Least-Squares Collocation

2022 ◽  
Vol 9 ◽  
Author(s):  
Hamad Al-Ajami ◽  
Ahmed Zaki ◽  
Mostafa Rabah ◽  
Mohamed El-Ashquer
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Geopotential Model ◽  
Gravimetric Geoid ◽  
Least Squares Collocation ◽  
Geoid Model ◽  
Terrestrial Gravity ◽  
Digital Elevation ◽  
Elevation Model ◽  
Gps Leveling

A new gravimetric geoid model, the KW-FLGM2021, is developed for Kuwait in this study. This new geoid model is driven by a combination of the XGM2019e-combined global geopotential model (GGM), terrestrial gravity, and the SRTM 3 global digital elevation model with a spatial resolution of three arc seconds. The KW-FLGM2021 has been computed by using the technique of Least Squares Collocation (LSC) with Remove-Compute-Restore (RCR) procedure. To evaluate the external accuracy of the KW-FLGM2021 gravimetric geoid model, GPS/leveling data were used. As a result of this evaluation, the residual of geoid heights obtained from the KW-FLGM2021 geoid model is 2.2 cm. The KW-FLGM2021 is possible to be recommended as the first accurate geoid model for Kuwait.

scholarly journals GEOMETRIC ASPECTS EVALUATION OF GNSS CONTROL NETWORK FOR DEFORMATION MONITORING IN THE JATIGEDE DAM REGION

2019 ◽  
Vol 15 (2) ◽  
pp. 167
Author(s):  
Made Ditha Ary Sanjaya ◽  
T. Aris Sunantyo ◽  
Nurrohmat Widjajanti
Keyword(s):  
Least Squares ◽  
Deformation Monitoring ◽  
Network Configuration ◽  
Control Networks ◽  
Quality Of Control ◽  
Least Squares Adjustment ◽  
Standard Deviations ◽  
Dam Deformation ◽  
Gnss Networks

Many factors led to dam construction failure so that deformation monitoring activities is needed in the area of the dam. Deformation monitoring is performed in order to detect a displacement at the control points of the dam. Jatigede Dam deformation monitoring system has been installed and started to operate, but there has been no evaluation of the geometry quality of control networks treated with IGS points for GNSS networks processing. Therefore, this study aims to evaluate the geometric quality of GNSS control networks on deformation monitoring of Jatigede Dam area. This research data includes the GNSS measurements of five CORS Jatigede Dam stations (R01, GG01, GCP04, GCP06, and GCP08) at doy 233 with network configuration scenarios of 12 IGS points on two quadrants (jat1), three quadrants (jat2), and four quadrants (jat3 and jat4). GNSS networks processing was done by GAMIT to obtain baseline vectors, followed by network processing usingparameter method of least squares adjustment. Networks processing with least squares adjustment aims to determine the most optimal  by precision and reliability criterion. Results of this study indicate that network configuration with 12 IGS stations in the two quadrants provides the most accurate coordinates of CORS dam stations. Standard deviations value of CORS station given by jat1 configuration are in the range of 2.7 up to 4.1 cm in X-Z components, whereas standard deviations in the Y component are in the range 5.8 up to 6.9 cm. An optimization assessment based on network strength, precision, and reliability factors shows optimum configuration by jat1.

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