scholarly journals Development and characterization of a single-line-of-sight framing camera

2001 ◽  
Vol 72 (1) ◽  
pp. 694-697 ◽  
Author(s):  
D. K. Bradley ◽  
P. M. Bell ◽  
A. K. L. Dymoke-Bradshaw ◽  
J. D. Hares ◽  
R. E. Bahr ◽  
...  
Keyword(s):  
Single Line ◽  
Line Of Sight ◽  
Framing Camera

scholarly journals Progress on the development of a single line of sight x-ray framing camera

2004 ◽  
Vol 75 (10) ◽  
pp. 4054-4056 ◽  
Author(s):  
D. K. Bradley ◽  
J. P. Holder ◽  
C. M. Damian ◽  
K. W. Piston ◽  
P. M. Bell ◽  
...  
Keyword(s):  
Single Line ◽  
Line Of Sight ◽  
X Ray ◽  
Framing Camera

Further development of a single line of sight x-ray framing camera

2003 ◽  
Vol 74 (3) ◽  
pp. 2191-2193 ◽  
Author(s):  
J. P. Holder ◽  
K. W. Piston ◽  
D. K. Bradley ◽  
P. M. Bell ◽  
A. K. L. Dymoke-Bradshaw ◽  
...  
Keyword(s):  
Single Line ◽  
Line Of Sight ◽  
X Ray ◽  
Further Development ◽  
Framing Camera

scholarly journals Characterization of Degenerate Configurations in Attitude Determination of Three-Vehicle Heterogeneous Formations

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4631
Author(s):  
Pedro Cruz ◽  
Pedro Batista
Keyword(s):  
Unique Solution ◽  
Multiple Solutions ◽  
Attitude Determination ◽  
Line Of Sight ◽  
Number Of Solutions ◽  
Relative Line ◽  
Heterogeneous Formations ◽  
Heterogeneous Formation

The existence of multiple solutions to an attitude determination problem impacts the design of estimation schemes, potentially increasing the errors by a significant value. It is therefore essential to identify such cases in any attitude problem. In this paper, the cases where multiple attitudes satisfy all constraints of a three-vehicle heterogeneous formation are identified. In the formation considered herein, the vehicles measure inertial references and relative line-of-sight vectors. Nonetheless, the line of sight between two elements of the formation is restricted, and these elements are denoted as deputies. The attitude determination problem is characterized relative to the number of solutions associated with each configuration of the formation. There are degenerate and ambiguous configurations that result in infinite or exactly two solutions, respectively. Otherwise, the problem has a unique solution. The degenerate configurations require some collinearity between independent measurements, whereas the ambiguous configurations result from symmetries in the formation measurements. The conditions which define all such configurations are determined in this work. Furthermore, the ambiguous subset of configurations is geometrically interpreted resorting to the planes defined by specific measurements. This subset is also shown to be a zero-measure subset of all possible configurations. Finally, a maneuver is simulated to illustrate and validate the conclusions. As a result of this analysis, it is concluded that, in general, the problem has one attitude solution. Nonetheless, there are configurations with two or infinite solutions, which are identified in this work.

First Demonstration of an Acousto-Optically Modulated Quantum Cascade Laser As a Broadband, Time-Resolved Combustion Diagnostic

2018 ◽  
Author(s):  
Zachary E. Loparo ◽  
Kareem Ahmed ◽  
Subith S. Vasu ◽  
Andrey V. Muraviev ◽  
Pedro Figueiredo ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Gas Turbines ◽  
Chemical Kinetic ◽  
Single Line ◽  
Line Of Sight ◽  
Spectral Measurements ◽  
Time Resolved ◽  
Quantum Cascade ◽  
No Formation ◽  
Multiple Species

We provide the first demonstration of an acousto-optically modulated quantum cascade laser (AOM QCL) system as a diagnostic for combustion by measuring nitric oxide (NO), a highly-regulated emission produced in gas turbines. The system provides time-resolved broadband spectral measurements of the present gas species via a single line of sight measurement, offering advantages over widely used narrowband absorption spectroscopy (e.g., the potential for simultaneous multi-species measurements using a single laser) and considerably faster (> 15kHz rates and potentially up to MHz) than sampling techniques which employ FTIR or GC/MS. The developed AOM QCL system yields fast tunable output covering a spectral range of 1725–1930 cm−1 with a linewidth of 10–15 cm−1. For the demonstration experiment, the AOM QCL system has been used to obtain time-resolved spectral measurements of NO formation during the shock heating of mixture of a 10% nitrous oxide (N2O) in a balance of argon over a temperature range of 1245–2517 K and a pressure range of 3.6–5.8 atm. Results were in good agreement with chemical kinetic simulations. The system shows revolutionary promise for making simultaneous time-resolved measurements of multiple species concentrations and temperature with a single line of sight measurement.

scholarly journals Densified Pupil Spectrograph as High-precision Radial Velocimetry: From Direct Measurement of the Universe’s Expansion History to Characterization of Nearby Habitable Planet Candidates

2022 ◽  
Vol 163 (2) ◽  
pp. 63
Author(s):  
Taro Matsuo ◽  
Thomas P. Greene ◽  
Mahdi Qezlou ◽  
Simeon Bird ◽  
Kiyotomo Ichiki ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Direct Measurement ◽  
High Precision ◽  
Resolving Power ◽  
Line Of Sight ◽  
High Dispersion ◽  
Velocity Measurements ◽  
Habitable Planet ◽  
Airy Disk

Abstract The direct measurement of the universe’s expansion history and the search for terrestrial planets in habitable zones around solar-type stars require extremely high-precision radial-velocity measures over a decade. This study proposes an approach for enabling high-precision radial-velocity measurements from space. The concept presents a combination of a high-dispersion densified pupil spectrograph and a novel line-of-sight monitor for telescopes. The precision of the radial-velocity measurements is determined by combining the spectrophotometric accuracy and the quality of the absorption lines in the recorded spectrum. Therefore, a highly dispersive densified pupil spectrograph proposed to perform stable spectroscopy can be utilized for high-precision radial-velocity measures. A concept involving the telescope’s line-of-sight monitor is developed to minimize the change of the telescope’s line of sight over a decade. This monitor allows the precise measurement of long-term telescope drift without any significant impact on the Airy disk when the densified pupil spectra are recorded. We analytically derive the uncertainty of the radial-velocity measurements, which is caused by the residual offset of the lines of sight at two epochs. We find that the error could be reduced down to approximately 1 cm s−1, and the precision will be limited by another factor (e.g., wavelength calibration uncertainty). A combination of the high-precision spectrophotometry and the high spectral resolving power could open a new path toward the characterization of nearby non-transiting habitable planet candidates orbiting late-type stars. We present two simple and compact highly dispersed densified pupil spectrograph designs for cosmology and exoplanet sciences.

scholarly journals ECE Diagnostic for the initial Operation of Wendelstein 7-X

2019 ◽  
Vol 203 ◽  
pp. 03007 ◽  
Author(s):  
Matthias Hirsch ◽  
Udo Höfel ◽  
Johan Willem Oosterbeek ◽  
Neha Chaudhary ◽  
Joachim Geiger ◽  
...  
Keyword(s):  
Noise Source ◽  
Michelson Interferometer ◽  
Frequency Resolution ◽  
Line Of Sight ◽  
Initial Operation ◽  
Cold Source ◽  
Mode Of Operation ◽  
Standard Mode ◽  
Telescope Optics

The ECE diagnostic at W7-X in its standard mode of operation measures in X2 mode polarization with a 32 channel radiometer in the frequency band around 140 GHz for central magnetic field 2.5T. The radiometer is calibrated by a noise source and the overall system absolutely calibrated by means of a hot-cold source placed outside the torus in front of a Gaussian telescope optics with identical geometry and transmission line as it is installed for the measurements in the plasma vessel. The system is supplemented with a 16 channel zoom device with 4 GHz span for higher frequency resolution at a suitable radial range and a Michelson interferometer for the characterization of higher harmonics sharing the same line of sight.

Characterization of temperature non-uniformity over a premixed CH4–air flame based on line-of-sight TDLAS

2016 ◽  
Vol 122 (1) ◽  
Author(s):  
Guangle Zhang ◽  
Jianguo Liu ◽  
Zhenyu Xu ◽  
Yabai He ◽  
Ruifeng Kan
Keyword(s):  
Line Of Sight ◽  
On Line

Shock Tube Demonstration of Acousto-Optically Modulated Quantum Cascade Laser as a Broadband, Time-Resolved Combustion Diagnostic

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Zachary E. Loparo ◽  
Andrey V. Muraviev ◽  
Pedro Figueiredo ◽  
Arkadiy Lyakh ◽  
Robert E. Peale ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Gas Turbines ◽  
Chemical Kinetic ◽  
Single Line ◽  
Line Of Sight ◽  
Spectral Measurements ◽  
Time Resolved ◽  
Quantum Cascade ◽  
No Formation ◽  
Multiple Species

We provide the first demonstration of an acousto-optically modulated quantum cascade laser (AOM QCL) system as a diagnostic for combustion by measuring nitric oxide (NO), a highly regulated emission produced in gas turbines. The system provides time-resolved broadband spectral measurements of the present gas species via a single line of sight measurement, offering advantages over widely used narrowband absorption spectroscopy (e.g., the potential for simultaneous multispecies measurements using a single laser) and considerably faster (>15 kHz rates and potentially up to MHz) than sampling techniques, which employ fourier transform infrared (FTIR) or GC/MS. The developed AOM QCL system yields fast tunable output covering a spectral range of 1725–1930 cm−1 with a linewidth of 10–15 cm−1. For the demonstration experiment, the AOM QCL system has been used to obtain time-resolved spectral measurements of NO formation during the shock heating of mixture of a 10% nitrous oxide (N2O) in a balance of argon over a temperature range of 1245–2517 K and a pressure range of 3.6–5.8 atm. Results were in good agreement with chemical kinetic simulations. The system shows revolutionary promise for making simultaneous time-resolved measurements of multiple species concentrations and temperature with a single line of sight measurement.

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