Improvement of the signal-to-noise ratio in interferometry using multi-frame high-dynamic-range and normalization algorithms

The paper describes application of standard gain calibration using redundancy for a 48-antenna prototype of Siberian Radioheliograph. Traditionally, for calibration, the visibilities were measured only between adjacent antennas since they have the highest signal-to-noise ratio and are sufficient for phase calibration. We have shown that this limited set of visibilities did not allow using the antenna array redundancy potential and obtaining images with a high dynamic range on a permanent basis. Images without amplitude calibration contain many artifacts and require special care when analyzed. The inclusion of visibility measurement between antennas with a double step made it possible to significantly increase the accuracy of solving the system of equations for amplitudes. Images constructed using both phase and amplitude calibrations do not have visible artifacts and are more reliable.

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Probing delayed-end reionization histories with the 21-cm LAE cross-power spectrum

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa749 ◽

2020 ◽

Vol 494 (1) ◽

pp. 703-718 ◽

Cited By ~ 1

Author(s):

Lewis H Weinberger ◽

Girish Kulkarni ◽

Martin G Haehnelt

Keyword(s):

Power Spectrum ◽

Dynamic Range ◽

Signal To Noise Ratio ◽

High Dynamic Range ◽

Integration Time ◽

Signal To Noise ◽

Total Signal ◽

The Cross ◽

Noise Ratio ◽

Cross Power Spectrum

ABSTRACT We model the 21-cm signal and Lyman-α emitter (LAE) population evolution during the epoch of reionization in order to predict the 21-cm LAE cross-power spectrum. We employ high-dynamic-range simulations of the intergalactic medium to create models that are consistent with constraints from the cosmic microwave background, Lyman-α forest, and LAE population statistics. Using these models we consider the evolution of the cross-power spectrum for a selection of realistic reionization histories and predict the sensitivity of current and upcoming surveys to measuring this signal. We find that the imprint of a delayed end to reionization can be observed by future surveys, and that strong constraints can be placed on the progression of reionization as late as z = 5.7 using a Subaru–SKA survey. We make predictions for the signal-to-noise ratios achievable by combinations of Subaru/PFS (Prime Focus Spectrograph) with the MWA, LOFAR, HERA, and SKA interferometers for an integration time of 1000 h. We find that a Subaru–SKA survey could measure the cross-power spectrum for a late reionization at z = 6.6 with a total signal-to-noise ratio greater than 5, making it possible to constrain both the timing and bubble size at the end of reionization. Furthermore, we find that expanding the current Subaru/PFS survey area and depth by a factor of three would double the total signal-to-noise ratio.

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Spherical logarithmic quantization and its application for DPCM

Facta universitatis - series Electronics and Energetics ◽

10.2298/fuee0402165h ◽

2004 ◽

Vol 17 (2) ◽

pp. 165-184 ◽

Cited By ~ 2

Author(s):

Johannes Huber ◽

Bernd Matschkal

Keyword(s):

Dynamic Range ◽

Signal To Noise Ratio ◽

Rate Distortion ◽

Differential Pulse ◽

High Dynamic Range ◽

Pulse Code Modulation ◽

Signal To Noise ◽

Differential Pulse Code Modulation ◽

Source Signal ◽

Noise Ratio

A new method for efficient digitizing analog signals while preserving the original waveform as close as possible with respect to the relative quantization error is presented. Logarithmic quantization is applied to short vectors of samples represented in sphere coordinates. The resulting advantages, i.e. a constant Signal-to-Noise Ratio over a very high dynamic range at a small loss with respect to rate-distortion theory are discussed. In order to increase the Signal-to-Noise Ratio (SNR) by exploitation of correlations within the source signal, a method of combining differential pulse code modulation (DPCM) with spherical logarithmic quantization is presented. The resulting technique achieves an efficient digital representation of waveforms with a high long term as well as segmental SNR at an extreme low delay of the signal.

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Calibration of Siberian Radioheliograph antenna gains using redundancy

Solar-Terrestrial Physics ◽

10.12737/stp-74202111 ◽

2021 ◽

Vol 7 (4) ◽

pp. 98-103

Author(s):

Mariia Globa ◽

Sergey Lesovoi

Keyword(s):

Antenna Array ◽

Dynamic Range ◽

Signal To Noise Ratio ◽

High Dynamic Range ◽

Special Care ◽

System Of Equations ◽

Signal To Noise ◽

Double Step ◽

Phase Calibration ◽

High Dynamic

The paper describes application of standard gain calibration using redundancy for a 48-antenna prototype of Siberian Radioheliograph. Traditionally, for calibration, the visibilities were measured only between adjacent antennas since they have the highest signal-to-noise ratio and are sufficient for phase calibration. We have shown that this limited set of visibilities did not allow using the antenna array redundancy potential and obtaining images with a high dynamic range on a permanent basis. Images without amplitude calibration contain many artifacts and require special care when analyzed. The inclusion of visibility measurement between antennas with a double step made it possible to significantly increase the accuracy of solving the system of equations for amplitudes. Images constructed using both phase and amplitude calibrations do not have visible artifacts and are more reliable.

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An Over 120dB Dynamic Range Linear Response Single Exposure CMOS Image Sensor with Two-stage Lateral Overflow Integration Trench Capacitors

Electronic Imaging ◽

10.2352/issn.2470-1173.2020.7.iss-143 ◽

2020 ◽

Vol 2020 (7) ◽

pp. 143-1-143-6 ◽

Cited By ~ 1

Author(s):

Yasuyuki Fujihara ◽

Maasa Murata ◽

Shota Nakayama ◽

Rihito Kuroda ◽

Shigetoshi Sugawa

Keyword(s):

Linear Response ◽

Dynamic Range ◽

Signal To Noise Ratio ◽

Cmos Image Sensor ◽

Image Sensor ◽

Signal To Noise ◽

Single Exposure ◽

Two Stage ◽

Noise Ratio ◽

Maximum Signal

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.

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