Analysis of relative error in detection caused by signal-induced noise in Na lidar system

Zhang, Yunpeng; Yi, Fan; Kong, Wei

doi:10.1007/s11430-017-9123-4

Cited by 4 publications

(2 citation statements)

References 20 publications

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“…The core flow sampling decreases the probability of interaction with the boundary layer of the flow, which is known to cause measurement inaccuracies. The accuracy of measurement is influenced by many parameters, such as signal-induced noise [9] and laser-induced noise [10,11]. Of particular concern in the Harvard Halogens instrument is that turbulence in the core flow is detrimental to the detection accuracy due to the risk it carries in transporting the molecules of interest into the boundary layer, where wall collisions and entrapment lead to a loss of molecules and undersampling [2].…”

Section: Introductionmentioning

confidence: 99%

Effects of Reynolds number and solidity ratio on advection dominated mixing in a high-altitude instrument

Pamarty

Mascarenhas

Anderson

2023

Meas. Sci. Technol.

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Due to the role of ClO and BrO in the rate-limiting step of the catalytic cycles enabling ozone loss, measurement of concentrations of these halogen molecules is of critical importance to understanding the loss rate of ozone in the stratosphere. A key advantage of in situ measurements is that these rate-limiting molecules can be observed simultaneously with ozone in the same volume element of the stratosphere, with high spatial and temporal resolution. Historically, these in situ measurements were made using instruments on the NASA ER-2 flight platform for a few hours at a time. However, the development and advancement of a high-altitude long-endurance (HALE) solar aircraft has made it possible to monitor these radicals continuously in the stratosphere. The slower flight speeds of the HALE aircraft will greatly improve molecule detection sensitivity and spatial resolution. To ensure proper mixing and accurate measurements, a quantitative dissection of the flow dynamics within the instrument architecture is required. Of particular importance are the turbulent behavior and the boundary layer growth, both of which affect measurement quality. The geometry of the NO injector used for titration is studied as a function of its solidity and the flight airspeed, to understand its effect on turbulence and boundary layer growth. A 3D Computational Fluid Dynamics simulation of an Eulerian mixture model is used to analyze the advection-dominated mixing inside the instrument. The injector inside the instrument is found to act as a flow-conditioning device, with a lower solidity causing the downstream flow to be increasingly turbulent. Additionally, a quantitative relationship between the Reynolds number of the inlet air and the volume fraction of the flow is demonstrated. Analysis of the boundary layer dependencies demonstrates that the boundary layer does not encroach on the optical sensing area in any of the cases.

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Section: Introductionmentioning

confidence: 99%

Effects of Reynolds number and solidity ratio on advection dominated mixing in a high-altitude instrument

Pamarty

Mascarenhas

Anderson

2023

Meas. Sci. Technol.

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“…The hard x-ray detector of Astro-E appears fake pre-trigger signals which are due to after pulses of the photomultiplier [6]. Photomultiplier tube would produce signal-induced noises that are usually considered to be the electron cloud that surrounds the photocathode or the fluorescence that is induced by ions striking the glass envelope of the PMT [7]. There are also more delayed after pulses that are possible results of the phosphorescence of glass or other insulators with activation energies well above kT [8].…”

Section: Introductionmentioning

confidence: 99%

The removal method and generation mechanism of spikes in Insight-HXMT/HE telescope

Wu,

Zhang,

et al. 2022

Preprint

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Spikes are some obvious sharp increases that appear on the raw light curves of Insight-HXMT's High Energy X-ray telescope(HE), which could have influences on data products like energy and power spectra. They are considered to be fake triggers generated by large signals. In this paper, we study the spikes' characteristic and propose two methods to remove spikes from the raw data. According to the different influences on energy and power spectra, the best parameters for removing the spikes is selected and used in the Insight-HXMT data analysis software. The generation mechanism of spikes is also studied using the backup HE detectors on ground and the spikes can be reduced by the electronic design.

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The removal method and generation mechanism of spikes in Insight-HXMT/HE telescope

Zhang

et al. 2022

Exp Astron

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Analysis of relative error in detection caused by signal-induced noise in Na lidar system

Cited by 4 publications

References 20 publications

Effects of Reynolds number and solidity ratio on advection dominated mixing in a high-altitude instrument

Effects of Reynolds number and solidity ratio on advection dominated mixing in a high-altitude instrument

The removal method and generation mechanism of spikes in Insight-HXMT/HE telescope

The removal method and generation mechanism of spikes in Insight-HXMT/HE telescope

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