scholarly journals Serendipitous observation of a coronal mass ejection during the total solar eclipse of 14 December 2020

2021 ◽  
Vol 13 ◽  
pp. 130004
Author(s):  
Guillermo Abramson
Keyword(s):  
Coronal Mass Ejection ◽  
Solar Eclipse ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Total Solar Eclipse ◽  
High Dynamic ◽  
Mass Ejection

We report observations of the total solar eclipse of 14 December 2020, during which a coronal mass ejection was seen to propagate. A comprehensive set of photographs covering a high dynamic range of exposure enabled characterization of its dimensions. Displacement of the front can be seen during the few minutes of totality.

scholarly journals Video cascade accumulation of the total solar eclipse on Svalbard 2015

2017 ◽  
Vol 6 (1) ◽  
pp. 9-14
Author(s):  
Fred Sigernes ◽  
Pål Gunnar Ellingsen ◽  
Noora Partamies ◽  
Mikko Syrjäsuo ◽  
Pål Brekke ◽  
...  
Keyword(s):  
Solar Eclipse ◽  
Solar Disk ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Total Solar Eclipse ◽  
Small Scale ◽  
Filter Technique ◽  
Video Recordings ◽  
High Dynamic ◽  
Hdr Image

Abstract. This work presents a novel image accumulation filter technique that reveals small-scale features and details from intense luminosity or high dynamic range (HDR) video recordings. It was discovered and developed from the analyses of the Norwegian Broadcasting Corporation (NRK) film of the total solar eclipse that occurred Friday 20 March 2015 in Longyearbyen (78° N, 15° E) on Svalbard, Norway. The result of the filter is fused with a HDR image of the corona and the Solar Dynamic Observatory (SDO) image of the solar disk.

scholarly journals Video cascade accumulation of the total solar eclipse on Svalbard 2015

2016 ◽  
Author(s):  
F. Sigernes ◽  
P. G. Ellingsen ◽  
N. Partamies ◽  
M. Syrjäsuo ◽  
P. Brekke ◽  
...  
Keyword(s):  
Solar Eclipse ◽  
Solar Disk ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Total Solar Eclipse ◽  
Small Scale ◽  
Video Recordings ◽  
High Dynamic ◽  
High Dynamic Range Video ◽  
Hdr Image

Abstract. This work presents a novel image accumulation filter technique that reveals small scale features and details from intense luminosity or high dynamic range video recordings. It was discovered and developed from the analyses of the Norwegian Broadcasting Corporation (NRK) film of the total solar eclipse that occurred Friday 20th of March 2015 in Longyearbyen (78° N, 15° E) on Svalbard, Norway. The result of the filter is fused with a High Dynamic Range (HDR) image of the Corona and the Solar Dynamic Observatory (SDO) image of the solar disk.

scholarly journals Relative sky radiance from multi-exposure all-sky camera images

2021 ◽  
Vol 14 (3) ◽  
pp. 2201-2217
Author(s):  
Juan C. Antuña-Sánchez ◽  
Roberto Román ◽  
Victoria E. Cachorro ◽  
Carlos Toledano ◽  
César López ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Quality Criteria ◽  
High Dynamic Range ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
High Dynamic ◽  
Sky Radiance ◽  
Black Level ◽  
Hdr Image

Abstract. All-sky cameras are frequently used to detect cloud cover; however, this work explores the use of these instruments for the more complex purpose of extracting relative sky radiances. An all-sky camera (SONA202-NF model) with three colour filters narrower than usual for this kind of cameras is configured to capture raw images at seven exposure times. A detailed camera characterization of the black level, readout noise, hot pixels and linear response is carried out. A methodology is proposed to obtain a linear high dynamic range (HDR) image and its uncertainty, which represents the relative sky radiance (in arbitrary units) maps at three effective wavelengths. The relative sky radiances are extracted from these maps and normalized by dividing every radiance of one channel by the sum of all radiances at this channel. Then, the normalized radiances are compared with the sky radiance measured at different sky points by a sun and sky photometer belonging to the Aerosol Robotic Network (AERONET). The camera radiances correlate with photometer ones except for scattering angles below 10∘, which is probably due to some light reflections on the fisheye lens and camera dome. Camera and photometer wavelengths are not coincident; hence, camera radiances are also compared with sky radiances simulated by a radiative transfer model at the same camera effective wavelengths. This comparison reveals an uncertainty on the normalized camera radiances of about 3.3 %, 4.3 % and 5.3 % for 467, 536 and 605 nm, respectively, if specific quality criteria are applied.

Characterization of short-pulse oscillators by means of a high-dynamic-range autocorrelation measurement

1995 ◽  
Vol 20 (18) ◽  
pp. 1889 ◽  
Author(s):  
A. Braun ◽  
D. Kopf ◽  
I. D. Jung ◽  
J. V. Rudd ◽  
H. Cheng ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Short Pulse ◽  
High Dynamic Range ◽  
High Dynamic ◽  
Autocorrelation Measurement

scholarly journals Relative sky radiance from multi-exposure all-sky camera images

2020 ◽  
Author(s):  
Juan C. Antuña-Sánchez ◽  
Roberto Román ◽  
Victoria E. Cachorro ◽  
Carlos Toledano ◽  
César López ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Quality Criteria ◽  
High Dynamic Range ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
High Dynamic ◽  
Sky Radiance ◽  
Black Level ◽  
Hdr Image

Abstract. All-sky cameras are frequently used to detect cloud cover; however, this work explores the use of these instruments for the more complex purpose of extracting relative sky radiances. An all-sky camera (SONA202-NF model) with three colour filters, narrower than usual for this kind of cameras, is configured to capture raw images at seven exposure times. A detailed camera characterization of the black level, readout noise, hot pixels and linear response is carried out. A methodology is proposed to obtain a linear high dynamic range (HDR) image and its uncertainty, which represents the relative sky radiance map at three effective wavelengths. The relative sky radiance (normalized by the sum of all radiances) is extracted from these maps and compared with the sky radiance measured at different sky points by a sun/sky photometer belonging to the Aerosol Robotic Network (AERONET). The camera radiances are in line with photometer ones excepting for scattering angles below 10º, which is probably due to some light reflections on the fisheye lens and camera dome. Camera and photometer wavelengths are not coincident, hence camera radiances are also compared with sky radiances simulated by a radiative transfer model at the same camera effective wavelengths. This comparison reveals an uncertainty on the normalized camera radiances about 3.3 %, 4.3 % and 5.3 % for 467, 536 and 605 nm, respectively, if specific quality criteria are applied.

High Speed Characterization of Pseudomorphic Hemt Structures Using a Very Low Noise Scintillation Detector

1993 ◽  
Vol 37 ◽  
pp. 145-151
Author(s):  
N. Loxley ◽  
S. Cockerton ◽  
B. K. Tanner
Keyword(s):  
Quality Assurance ◽  
Scintillation Detector ◽  
High Speed ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Low Noise ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Dynamic

AbstractWe show that a very low noise, high dynamic range scintillation detector has major advantages over conventional detectors for characterization of pseudomorphic HEMT structures by high resolution X-ray diffraction. We show that the reduced background enables a second modulation period to be detected, enabling the thickness and composition to be determined independently. Using a conventional X-ray generator and diffractometer we demonstrate that, in a single scan taking only 10 seconds, we are able to obtain sufficiently good data to provide quality assurance.

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