scholarly journals A wide field, high dynamic range, stereographic viewer

2002 ◽  
Vol 2 (10) ◽  
pp. 2-2 ◽  
Author(s):  
G. Ward
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Wide Field ◽  
High Dynamic

scholarly journals High-dynamic-range imaging for cloud segmentation

2018 ◽  
Vol 11 (4) ◽  
pp. 2041-2049 ◽  
Author(s):  
Soumyabrata Dev ◽  
Florian M. Savoy ◽  
Yee Hui Lee ◽  
Stefan Winkler
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Wide Field ◽  
Single Shot ◽  
Generation Process ◽  
Image Generation ◽  
Large Dynamic Range ◽  
Exposure Fusion ◽  
Wide Field Of View ◽  
High Dynamic

Abstract. Sky–cloud images obtained from ground-based sky cameras are usually captured using a fisheye lens with a wide field of view. However, the sky exhibits a large dynamic range in terms of luminance, more than a conventional camera can capture. It is thus difficult to capture the details of an entire scene with a regular camera in a single shot. In most cases, the circumsolar region is overexposed, and the regions near the horizon are underexposed. This renders cloud segmentation for such images difficult. In this paper, we propose HDRCloudSeg – an effective method for cloud segmentation using high-dynamic-range (HDR) imaging based on multi-exposure fusion. We describe the HDR image generation process and release a new database to the community for benchmarking. Our proposed approach is the first using HDR radiance maps for cloud segmentation and achieves very good results.

scholarly journals High-Dynamic-Range Imaging for Cloud Segmentation

2017 ◽  
Author(s):  
Soumyabrata Dev ◽  
Florian M. Savoy ◽  
Yee Hui Lee ◽  
Stefan Winkler
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Wide Field ◽  
Single Shot ◽  
Generation Process ◽  
Large Dynamic Range ◽  
Exposure Fusion ◽  
Wide Field Of View ◽  
High Dynamic ◽  
Fish Eye

Abstract. Sky/cloud images obtained from ground-based sky-cameras are usually captured using a fish-eye lens with a wide field of view. However, the sky exhibits a large dynamic range in terms of luminance, more than a conventional camera can capture. It is thus difficult to capture the details of an entire scene with a regular camera in a single shot. In most cases, the circumsolar region is over-exposed, and the regions near the horizon are under-exposed. This renders cloud segmentation for such images difficult. In this paper, we propose HDRSeg – an effective method for cloud segmentation using High-Dynamic-Range (HDR) imaging based on multi-exposure fusion. We describe the HDR generation process and release a new database to the community for benchmarking. Our proposed approach is the first using HDR images for cloud segmentation and achieves very good results.

scholarly journals Adaptive-scale wide-field reconstruction for radio synthesis imaging

2020 ◽  
Vol 640 ◽  
pp. A80
Author(s):  
L. Zhang ◽  
L. G. Mi ◽  
M. Zhang ◽  
X. Liu ◽  
C. L. He
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Wide Field ◽  
Observation Data ◽  
Field Observations ◽  
High Dynamic Range Imaging ◽  
Range Imaging ◽  
Low Frequencies ◽  
Very Large Array ◽  
High Dynamic

Sky curvature and non-coplanar effects, caused by low frequencies, long baselines, or small apertures in wide field-of-view instruments such as the Square Kilometre Array (SKA), significantly limit the imaging performance of an interferometric array. High dynamic range imaging essentially requires both an excellent sky model and the correction of imaging factors such as non-coplanar effects. New CLEAN deconvolution with adaptive-scale modeling already has the ability to construct significantly better narrow-band sky models. However, the application of wide-field observations based on modern arrays has not yet been jointly explored. We present a new wide-field imager that can model the sky on an adaptive-scale basis, and the sky curvature and the effects of non-coplanar observations with the w-projection method. The degradation caused by the dirty beam due to incomplete spatial frequency sampling is eliminated during sky model construction by our new method, while the w-projection mainly removes distortion of sources far from the image phase center. Applying our imager to simulated SKA data and the real observation data of the Karl G. Jansky Very Large Array (an SKA pathfinder) suggested that our imager can handle the effects of wide-field observations well and can reconstruct more accurate images. This provides a route for high dynamic range imaging of SKA wide-field observations, which is an important step forward in the development of the SKA imaging pipeline.

Australian SKA Pathfinder: A High-Dynamic Range Wide-Field of View Survey Telescope

2009 ◽  
Vol 97 (8) ◽  
pp. 1507-1521 ◽  
Author(s):  
David R. DeBoer ◽  
Russell G. Gough ◽  
John D. Bunton ◽  
Tim J. Cornwell ◽  
Ron J. Beresford ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Field Of View ◽  
Wide Field ◽  
Wide Field Of View ◽  
High Dynamic

scholarly journals SunCET: The Sun Coronal Ejection Tracker Concept

2021 ◽  
Author(s):  
James Paul Mason ◽  
Phillip C Chamberlin ◽  
Daniel Seaton ◽  
Joan Burkepile ◽  
Robin Colaninno ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Extreme Ultraviolet ◽  
High Dynamic Range ◽  
Field Of View ◽  
Integration Time ◽  
Wide Field ◽  
The Sun ◽  
Wide Field Of View ◽  
High Dynamic ◽  
Short Integration Time

The Sun Coronal Ejection Tracker (SunCET) is an extreme ultraviolet imager and spectrograph instrument concept for tracking coronal mass ejections through the region where they experience the majority of their acceration: the difficult-to-observe middle corona. It contains a wide field of view (0--4~\Rs) imager and a 1~\AA\ spectral-resolution-irradiance spectrograph spanning 170--340~\AA. It leverages new detector technology to read out different areas of the detector with different integration times, resulting in what we call ``simultaneous high dynamic range", as opposed to the traditional high dynamic range camera technique of subsequent full-frame images that are then combined in post-processing. This allows us to image the bright solar disk with short integration time, the middle corona with a long integration time, and the spectra with their own, independent integration time. Thus, SunCET does not require the use of an opaque or filtered occulter. SunCET is also compact --- $\sim$15 $\times$ 15 $\times$ 10~cm in volume --- making it an ideal instrument for a CubeSat or a small, complimentary addition to a larger mission.

High-dynamic-range interferometric bragg-cell spectrum analyser

1986 ◽  
Vol 133 (1) ◽  
pp. 26
Author(s):  
J. Mellis ◽  
G.R. Adams ◽  
K.D. Ward
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Spectrum Analyser ◽  
High Dynamic
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