11,102 research outputs found
Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation
We describe the concept and procedure of drifted-charge extraction developed
in the MicroBooNE experiment, a single-phase liquid argon time projection
chamber (LArTPC). This technique converts the raw digitized TPC waveform to the
number of ionization electrons passing through a wire plane at a given time. A
robust recovery of the number of ionization electrons from both induction and
collection anode wire planes will augment the 3D reconstruction, and is
particularly important for tomographic reconstruction algorithms. A number of
building blocks of the overall procedure are described. The performance of the
signal processing is quantitatively evaluated by comparing extracted charge
with the true charge through a detailed TPC detector simulation taking into
account position-dependent induced current inside a single wire region and
across multiple wires. Some areas for further improvement of the performance of
the charge extraction procedure are also discussed.Comment: 60 pages, 36 figures. The second part of this work can be found at
arXiv:1804.0258
Fundamental Imaging Limits of Radio Telescope Arrays
The fidelity of radio astronomical images is generally assessed by practical
experience, i.e. using rules of thumb, although some aspects and cases have
been treated rigorously. In this paper we present a mathematical framework
capable of describing the fundamental limits of radio astronomical imaging
problems. Although the data model assumes a single snapshot observation, i.e.
variations in time and frequency are not considered, this framework is
sufficiently general to allow extension to synthesis observations. Using tools
from statistical signal processing and linear algebra, we discuss the
tractability of the imaging and deconvolution problem, the redistribution of
noise in the map by the imaging and deconvolution process, the covariance of
the image values due to propagation of calibration errors and thermal noise and
the upper limit on the number of sources tractable by self calibration. The
combination of covariance of the image values and the number of tractable
sources determines the effective noise floor achievable in the imaging process.
The effective noise provides a better figure of merit than dynamic range since
it includes the spatial variations of the noise. Our results provide handles
for improving the imaging performance by design of the array.Comment: 12 pages, 8 figure
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