scholarly journals Wide Field Imaging and Photometry by 2k × 2k CCD

1994 ◽  
Vol 161 ◽  
pp. 17-19
Author(s):  
J.-S. Chen
Keyword(s):  
Field Of View ◽  
Large Field ◽  
Wide Field ◽  
List Type ◽  
Schmidt Telescope ◽  
Compressed Images ◽  
Basic Performance ◽  
Uv Coating ◽  
Field Imaging ◽  
Wide Field Imaging

The Ford Aerospace 2048 × 2048 CCD with UV coating is used at the BAO 60/90 cm f/3 Schmidt telescope focal plane, giving a field-of-view of about one square degree and spatial resolution of 1.67 arcsecond per pixel. The paper reviews the following topics: 1) basic performance of the system; 2) anti-blooming technique for a large field CCD; 3) flat fielding for a large field CCD; 4) photometric properties of compressed images.

scholarly journals Wide-Field-Imaging 3-Mirror-Systems by High Light Gathering Power and a Wide-Field Optical System for the ‘Large Imaging Telescope’ (Lite)

1994 ◽  
Vol 161 ◽  
pp. 101-107
Author(s):  
U. Laux
Keyword(s):  
Optical System ◽  
High Light ◽  
Field Of View ◽  
Wide Field ◽  
Light Gathering Power ◽  
Imaging Telescope ◽  
Light Gathering ◽  
Field Imaging ◽  
Wide Field Imaging

The desire of astronomers for wide field telescope systems which surpass the RCC (1:8 max. 1.5 degree) in light gathering power and field of view are relative concrete today. For this type of telescope, detectors planned ARE CCDs in multichip arrangement.

scholarly journals Fabrication and Characterization of Curved Compound Eyes Based on Multifocal Microlenses

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 854 ◽  
Author(s):  
Gaoge Lian ◽  
Yongshun Liu ◽  
KeKai Tao ◽  
Huaming Xing ◽  
Ruxia Huang ◽  
...  
Keyword(s):  
Compound Eye ◽  
Accurate Method ◽  
Field Of View ◽  
Curved Surface ◽  
Compound Eyes ◽  
Wide Field ◽  
Wide Field Of View ◽  
Field Imaging ◽  
Wide Field Imaging

Curved compound eyes have generated great interest owing to the wide field of view but the application of devices is hindered for the lack of proper detectors. One-lens curved compound eyes with multi-focal microlenses provide a solution for wide field imaging integrated in a commercial photo-detector. However, it is still a challenge for manufacturing this kind of compound eye. In this paper, a rapid and accurate method is proposed by a combination of photolithography, hot embossing, soft photolithography, and gas-assisted deformation techniques. Microlens arrays with different focal lengths were firstly obtained on a polymer, and then the planar structure was converted to the curved surface. A total of 581 compound eyes with diameters ranging from 152.8 µm to 240.9 µm were successfully obtained on one curved surface within a few hours, and the field of view of the compound eyes exceeded 108°. To verify the characteristics of the fabricated compound eyes, morphology deviation was measured by a probe profile and a scanning electron microscope. The optical performance and imaging capability were also tested and analyzed. As a result, the ommatidia made up of microlenses showed not only high accuracy in morphology, but also imaging uniformity on a focal plane. This flexible massive fabrication of compound eyes indicates great potential for miniaturized imaging systems.

scholarly journals Subaru Hyper Suprime Cam Survey of the Andromeda Halo

2015 ◽  
Vol 11 (S317) ◽  
pp. 278-279
Author(s):  
Masashi Chiba ◽  
Mikito Tanaka ◽  
Yutaka Komiyama
Keyword(s):  
Progress Report ◽  
Field Of View ◽  
Wide Field ◽  
Field Imaging ◽  
Wide Field Imaging

AbstractWe present a progress report on our deep and wide-field imaging survey of the Andromeda halo with Hyper Suprime Cam (HSC) mounted on Subaru. HSC is the upgraded prime focus camera after Suprime-Cam, having a field of view of 1.77 square degree (1.5 degree in diameter), namely about 10 times larger than that of Suprime-Cam. This camera will thus offer us great opportunities to explore unique and legacy surveys for the Andromeda halo, as well as for other Galactic Archaeology science cases.

scholarly journals The Modernization of the Pulkovo Photographic (Photoelectric) Vertical Circle by a CCD Array

1995 ◽  
Vol 167 ◽  
pp. 333-334
Author(s):  
G. A. Goncharov ◽  
B. K. Bagildinsky ◽  
E. V. Kornilov ◽  
D. D. Polojentsev ◽  
K. V. Rumyantsev ◽  
...  
Keyword(s):  
Focal Plane ◽  
Focal Length ◽  
Wide Field ◽  
List Type ◽  
Type Number ◽  
Pulkovo Observatory ◽  
Vertical Circle ◽  
Ccd Array ◽  
Field Imaging ◽  
Wide Field Imaging

The Zverev photographic vertical circle (PVC) of the Pulkovo observatory is in the process of modernization. The features of the vertical circle are: a)Maksutov mirror-lens optical system with small aberrations and wide passband: aperture: 20 cm, focal length: 200 cm, focal scale: 103 arcsec/mm.b)Very compact instrument: 140 cm total length, 60 cm — tube.c)Wide field: 25 × 25 mm = 40′ × 40′. Wide-field imaging can be combined with meridian observations.d)Easily-reversible instrument: reversing takes less than 30 seconds.e)Two divided vertical circles of glass. Photoelectric circle reading microscopes.f)Photographic micrometer in focal plane. This will be changed with a CCD micrometer.

scholarly journals Wide field imaging of Giant Molecular Clouds with the ATA

2007 ◽  
Vol 3 (S242) ◽  
pp. 230-231
Author(s):  
James R. Forster
Keyword(s):  
Large Field ◽  
Wide Field ◽  
Radio Telescopes ◽  
Giant Molecular Clouds ◽  
Telescope Array ◽  
Large N ◽  
Full Picture ◽  
New Generation ◽  
Field Imaging ◽  
Wide Field Imaging

AbstractGalactic Giant Molecular Cloud (GMC) complexes are among the largest objects in the sky. In order to get the full picture of Galactic star formation a large field of view is important. The Allen Telescope Array (ATA) is the first of a new generation of large-N, small-D radio telescopes designed to provide high quality images on large angular scales. We present here the first wide field images of GMCs made with the ATA.

scholarly journals Wide-field X-ray Optics

1995 ◽  
Vol 151 ◽  
pp. 435-438
Author(s):  
René Hudec ◽  
Adolf Inneman ◽  
Ladislav Pina ◽  
Petr Řehák ◽  
Paul Gorenstein
Keyword(s):  
Field Of View ◽  
Innovative Technology ◽  
Wide Field ◽  
Two Dimensional ◽  
Ray Optics ◽  
X Ray ◽  
Field Imaging ◽  
Wide Field Imaging ◽  
Lobster Eye

AbstractClassical X-ray mirror optics usually has a limited Field of View (FoV) of ∼ 1°. Wide-field imaging can be achieved by lobster-eye type reflecting X-ray optics. We summarise several different approaches and suggest an innovative technology for the production of X-ray reflecting flats and cells necessary to develop one- or two-dimensional wide-field X-ray optics. The technology is based on double-sided, replicated reflecting foils produced by electroforming and CF/composite technologies.

scholarly journals Near-Infrared Imaging by a Schmidt Telescope

1994 ◽  
Vol 161 ◽  
pp. 89-90
Author(s):  
K. Yanagisawa ◽  
N. Itoh ◽  
T. Ichikawa ◽  
K. Tarusawa ◽  
M. Ueno
Keyword(s):  
Thermal Radiation ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Image Resolution ◽  
Wide Field ◽  
Schmidt Telescope ◽  
Large Format ◽  
Array Camera ◽  
Field Imaging ◽  
Wide Field Imaging

We have carried out wide field imaging observations in the near-infrared (J, H and K′ band) with a large format array camera attached to the prime focus of the 105 cm Schmidt telescope at Kiso Observatory. The image resolution, limiting magnitudes and the effect of thermal radiation are discussed.

scholarly journals Separation of hemodynamic signals from GCaMP fluorescence measured with wide-field imaging

2020 ◽  
Vol 123 (1) ◽  
pp. 356-366 ◽  
Author(s):  
M. T. Valley ◽  
M. G. Moore ◽  
J. Zhuang ◽  
N. Mesa ◽  
D. Castelli ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Spatial Model ◽  
Sampling Rate ◽  
Large Field ◽  
Physical Parameters ◽  
Wide Field ◽  
Imaging Data ◽  
Calcium Signals ◽  
Field Imaging ◽  
Wide Field Imaging

Wide-field calcium imaging is often used to measure brain dynamics in behaving mice. With a large field of view and a high sampling rate, wide-field imaging can monitor activity from several distant cortical areas simultaneously, revealing cortical interactions. Interpretation of wide-field images is complicated, however, by the absorption of light by hemoglobin, which can substantially affect the measured fluorescence. One approach to separating hemodynamics and calcium signals is to use multiwavelength backscatter recordings to measure light absorption by hemoglobin. Following this approach, we develop a spatially detailed regression-based method to estimate hemodynamics. This Spatial Model is based on a linear form of the Beer–Lambert relationship but is fit at every pixel in the image and does not rely on the estimation of physical parameters. In awake mice of three transgenic lines, the Spatial Model offers improved separation of hemodynamics and changes in GCaMP fluorescence. The improvement is pronounced near blood vessels and, in contrast with the Beer–Lambert equations, can remove vascular artifacts along the sagittal midline and in general permits more accurate fluorescence-based determination of neuronal activity across the cortex. NEW & NOTEWORTHY This paper addresses a well-known and strong source of contamination in wide-field calcium-imaging data: hemodynamics. To guide researchers toward the best method to separate calcium signals from hemodynamics, we compare the performance of several methods in three commonly used mouse lines and present a novel regression model that outperforms the other techniques we consider.

scholarly journals The Importance of Wide-Field Imaging

1994 ◽  
Vol 161 ◽  
pp. 3-11
Author(s):  
V.A. Lipovetsky
Keyword(s):  
Exposure Time ◽  
Wide Field ◽  
Schmidt Telescope ◽  
Byurakan Survey ◽  
First Byurakan Survey ◽  
Survey Techniques ◽  
Field Imaging ◽  
Wide Field Imaging

The oncoming meeting and the big group of specialists gathered here reminds me of the late sixties, when I started the search for Markarian galaxies at the Byurakan Observatory. We carried out the survey with a 1 m Schmidt telescope (f/2.1). The First Byurakan Survey (FBS) consisted of more than two thousand plates with an exposure time of 30–60 minutes per plate. While guiding the telescope I therefore had plenty of time to think on future survey techniques.

scholarly journals Beam Combination for Wide Field Imaging

1994 ◽  
Vol 158 ◽  
pp. 83-90
Author(s):  
M. Tallon ◽  
I. Tallon-Bosc
Keyword(s):  
Image Plane ◽  
Field Of View ◽  
Combination Method ◽  
Wide Field ◽  
Radio Interferometry ◽  
Beam Combination ◽  
Stellar Interferometer ◽  
Field Imaging ◽  
Wide Field Imaging ◽  
Pupil Plane

Several limitations reduce the field of view in radio-interferometry. With an optical array, two of them can be overcome to some extent according to the beam combination method. A beam combination in the pupil plane can completely overcome one of them. In the image plane, a beam combination obeying the rules of geometrical optics can overcome both limitations in principle, but is difficult to achieve in practice. We discuss particularly the real case of a Michelson Stellar Interferometer where a periscope partially re-introduces these limitations, yielding a trade-off between the extension of the field of view and the use of the periscope.

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