scholarly journals Review of Linked Array Instruments

1989 ◽  
Vol 8 ◽  
pp. 551-552
Author(s):  
R.D. Ekers
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Angular Resolution ◽  
Research Tool ◽  
Aperture Synthesis ◽  
High Angular Resolution ◽  
Radio Telescopes ◽  
Astronomical Research ◽  
Full Operation ◽  
New Facilities

At cm wavelengths aperture synthesis radio-telescopes (arrays of linked antennas which synthesize an image of the sky with high angular resolution) are now becoming the dominant astronomical research tool. Major new facilities such as the VLA are in full operation, others such as the Australia Telescope are nearing completion and a number of telescopes designed to form images in real time have been converted to operate in the aperture synthesis mode (e.g. MOST, Bologna Cross). See Napier et al. (1983) for a review of modern synthesis telescopes. The high resolution, sensitivity and freedom from confusion have led the aperture synthesis telescopes into very diverse astronomical applications.

scholarly journals Introduction to the Joint Commission Meeting on High Resolution Imaging from the Ground

1989 ◽  
Vol 8 ◽  
pp. 545-546
Author(s):  
John Davis
Keyword(s):  
High Resolution ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
High Resolution Imaging ◽  
Wide Range ◽  
High Resolution Images ◽  
Resolution Imaging ◽  
Optical Wavelengths ◽  
To Come ◽  
Very High

As a result of advances in instrumentation and techniques, from radio through to optical wavelengths, we have before us the prospect of producing very high resolution images of a wide range of objects across this entire spectral range. This prospect, and the new knowledge and discoveries that may be anticipated from it, lie behind an upsurge in interest in high resolution imaging from the ground. Several new high angular resolution instruments for radio, infrared, and optical wavelengths are expected to come into operation before the 1991 IAU General Assembly.

scholarly journals High-resolution near-IR imaging of the WCD(+OB) environments: pinwheels

2003 ◽  
Vol 212 ◽  
pp. 121-129 ◽  
Author(s):  
Peter G. Tuthill ◽  
John D. Monnier ◽  
William C. Danchi ◽  
Nils H. Turner
Keyword(s):  
High Resolution ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Dust Formation ◽  
Near Ir ◽  
Ir Imaging ◽  
Fundamental Information

A small number of Wolf-Rayet colliding-wind binaries studied at extremely high angular resolution show elegant dust plumes with an intuitive geometry: that of an Archimedian spiral. A great deal of fundamental information on the binary and the winds is encoded, ultimately teaching us about dust formation and wind-wind collision zones in these fascinating systems. New results are presented summarizing a concerted campaign encompassing a number of systems studied with various techniques over the last five years.

Investigation of the Chromosphere–Corona Interface with the Upgraded Very High Angular Resolution Ultraviolet Telescope (VAULT2.0)

2016 ◽  
Vol 05 (01) ◽  
pp. 1640003 ◽  
Author(s):  
Angelos Vourlidas ◽  
Samuel Tun Beltran ◽  
Georgios Chintzoglou ◽  
Kevin Eisenhower ◽  
Clarence Korendyke ◽  
...  
Keyword(s):  
High Resolution ◽  
Angular Resolution ◽  
Solar Spectrum ◽  
High Angular Resolution ◽  
High Resolution Data ◽  
Lyman Alpha ◽  
And Performance ◽  
White Sands ◽  
Very High ◽  
Resolution Data

Very high angular resolution ultraviolet telescope (VAULT2.0) is a Lyman-alpha (Ly[Formula: see text]; 1216[Formula: see text]Å) spectroheliograph designed to observe the upper chromospheric region of the solar atmosphere with high spatial ([Formula: see text]) and temporal (8[Formula: see text]s) resolution. Besides being the brightest line in the solar spectrum, Ly[Formula: see text] emission arises at the temperature interface between coronal and chromospheric plasmas and may, hence, hold important clues about the transfer of mass and energy to the solar corona. VAULT2.0 is an upgrade of the previously flown VAULT rocket and was launched successfully on September 30, 2014 from White Sands Missile Range (WSMR). The target was AR12172 midway toward the southwestern limb. We obtained 33 images at 8[Formula: see text]s cadence at arc second resolution due to hardware problems. The science campaign was a resounding success, with all space and ground-based instruments obtaining high-resolution data at the same location within the AR. We discuss the science rationale, instrument upgrades, and performance during the first flight and present some preliminary science results.

scholarly journals Near-IR Solar Coronal Observations with New-Technology Reflecting Coronographs

1994 ◽  
Vol 154 ◽  
pp. 603-608
Author(s):  
Raymond N. Smartt ◽  
Serge Koutchmy ◽  
Jacques-Clair NoëNs
Keyword(s):  
High Resolution ◽  
Angular Resolution ◽  
High Sensitivity ◽  
Field Measurements ◽  
Coronal Magnetic Field ◽  
Photon Flux ◽  
Objective Lens ◽  
High Angular Resolution ◽  
Intrinsic Polarization ◽  
Near Ir

Emission-line and K-coronal observations in the IR have the significant advantage of reduced sky brightness compared with the visible, while the effects of seeing are also reduced. Moreover, strong lines are available in the near-IR. Examples of the current capabilities of IR coronal observations using conventional Lyot coronagraphs are discussed briefly. Photometric measurements using the two IR lines of Fe XIII (10,747 Å and 10,798 Å), together with the Fe XIII 3,388 Å line, have provided a valuable electron-density diagnostic, but with low-angular-resolution. The 10,747 Å line has high intrinsic polarization. It has been used for extensive coronal magnetic field measurements, but only the direction of the field, and that with modest angular resolution, has been achieved due basically to flux limitations. Such studies suffer from the lack of high angular resolution and high photon flux. Moreover, the chromatic properties of a singlet objective lens preclude simultaneous observations at widely-differing wavelengths of the important inner coronal region. A coronagraph based on a mirror objective avoids such problems. Further, comparatively high-resolution and high-sensitivity arrays are now available with quantum efficiencies up to 90%. Reflecting coronagraphs with advanced arrays then provide the possibility of obtaining high-resolution images in the infrared to carry out a wide variety of studies crucial to many of the outstanding problems in coronal physics. A program for the development of reflecting coronagraphs is described briefly, with an emphasis on applications to IR coronal studies.

Plans for the Australian Synthesis Telescope

1976 ◽  
Vol 3 (1) ◽  
pp. 7-11 ◽  
Author(s):  
K. J. Wellington
Keyword(s):  
Radio Astronomy ◽  
Angular Resolution ◽  
High Sensitivity ◽  
Aperture Synthesis ◽  
High Angular Resolution ◽  
The Past ◽  
New Synthesis

A major requirement of modern radio astronomy is the attainment of the highest possible angular resolution. This high angular resolution should be matched by a high sensitivity and by spectral and polarization capabilities. Study and experience have shown that no form of telescope is more effective in this respect than the aperture synthesis type. The past few years have seen a growing realization amongst astronomers, both here and overseas, of the need for a new synthesis telescope able to observe the full southern sky. This realization has been stimulated by several factors:

scholarly journals Radio Source Variability as a Tool for Very High Resolution

1994 ◽  
Vol 158 ◽  
pp. 201-203
Author(s):  
N. Shapirovskaya ◽  
O. B. Slee ◽  
P. Hughes ◽  
G. Tsarevsky
Keyword(s):  
High Resolution ◽  
Radio Source ◽  
Time Scale ◽  
High Frequency ◽  
Angular Resolution ◽  
Good Evidence ◽  
High Angular Resolution ◽  
Intrinsic Variability ◽  
Interstellar Plasma ◽  
Very High

If flux density variability is intrinsic to extragalactic sources, then the shortest time scale of the variability yields an extremely high angular resolution. There is, however, good evidence that some of the variability is due to refractive scintillation in our galaxy's interstellar plasma turbulence. The effect, initially discovered at low radio frequencies, is here shown to extend into the GHz band, which, up to now, has been assumed to display only the intrinsic variability. We conclude that further study in both the intermediate and high frequency bands needed to separate the intrinsic and extrinsic components of variability.

scholarly journals Astrometric microlensing with the RadioAstron space mission

2007 ◽  
Vol 3 (S248) ◽  
pp. 387-390
Author(s):  
A. F. Zakharov
Keyword(s):  
Angular Resolution ◽  
High Sensitivity ◽  
Space Mission ◽  
High Angular Resolution ◽  
Radio Telescopes ◽  
Ground Support ◽  
Direct Observations ◽  
The Earth ◽  
Space Agency ◽  
Radio Band

AbstractAccording to a revised schedule of the Russian Space Agency, in October 2008 the 10 m space telescope RadioAstron will be launched in a high eccentric orbit around the Earth. Acting together with ground based radio telescopes, the VLBI interferometer with a ground-space arm will operate. The interferometer will have extraordinary angular resolution of a few microarcsecond (μas) at the shortest wavelength (1.35 cm). Since typical angular scales for gravitational microlensing are at the μas level for cosmological locations of sources and microlenses, in principle there is a chance to resolve microimages and (or) at least, detect astrometrical shift of bright point like images. In particular, gravitationally lensed systems, such as B1600+434, where in radio band a signature of microlensing is found, look suitable for direct observations of microlensing, since microlensing with the RadioAstron interferometer may be detected in the future (considering its high angular resolution and a relatively high sensitivity and assuming a ground support by the advanced radio telescopes).

scholarly journals High Resolution Observations of CO in PNe

1993 ◽  
Vol 155 ◽  
pp. 225-225
Author(s):  
K.M. Shibata ◽  
S. Deguchi ◽  
T. Kasuga ◽  
S. Tamura ◽  
N. Hirano ◽  
...  
Keyword(s):  
High Resolution ◽  
Angular Resolution ◽  
Aperture Synthesis

We have made aperture synthesis observations of 12CO(J=1−0) emission IRAS 21282+5050, CRL 618 and M 1–7 using the Nobeyama Millimeter Array (NMA). We observed with 3 or 2 configurations and obtained an angular resolution of 3″.2 × 3.1, 3″.6 × 3″.5 and 4″.3 × 3″.8.

scholarly journals REMOTE ATTITUDE SENSING BASED ON HIGH-SPEED MUELLER MATRIX ELLIPSOMETRY

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 607-614
Author(s):  
S. Zhang ◽  
H. Jiang ◽  
H. Gu ◽  
X. Chen ◽  
S. Liu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Angular Resolution ◽  
Mueller Matrix ◽  
Moving Object ◽  
High Angular Resolution ◽  
High Temporal Resolution ◽  
Theoretical Derivation ◽  
The Real ◽  
Attitude Tracking

Abstract. The attitude metrology of moving objects has always been a hot topic in engineering applications. In this article, a novel optical method based on the high-speed Mueller matrix ellipsometry (MME) is proposed for real-time remote attitude sensing. With the help of an electric level, all the attitude angles of a free-moving object with a birefringent waveplate attached can be simultaneously extracted in real time. Compared with existing ellipsometry-based attitude metrology that can only be used in the transmission mode, the proposed method with the advantages of the high-speed MME can expand the application to both the transmission and reflection modes while maintaining higher accuracy and robustness in an ultra-large measurement range. The basic principle is presented via theoretical derivation, and the change in the Mueller matrix of the birefringent waveplate versus the attitude angles is explored in the simulated experiments. In a series of the dynamic experiments, with the extremely high temporal resolution and accuracy of the high-speed MME, an angular resolution up to 0.00022° and an angular accuracy better than 0.01° are achieved in the real-time attitude tracking of the free-moving object. As an additional benefit, the real-time angular velocity and acceleration of all the attitude angles can be obtained simultaneously. These experimental results demonstrate that the proposed attitude metrology is ready to be applied to the real-time remote attitude sensing with high angular resolution and accuracy.

scholarly journals A high resolution H I study of the ISM local to WR 132 and WR 140

1999 ◽  
Vol 193 ◽  
pp. 334-335
Author(s):  
E. Marcelo Arnal
Keyword(s):  
High Resolution ◽  
Interstellar Medium ◽  
Joint Action ◽  
Angular Resolution ◽  
Interaction Process ◽  
High Angular Resolution ◽  
Velocity Range ◽  
Matter Distribution

The neutral matter distribution from the interstellar medium located in the vicinity of the galactic WR stars WR 132 and WR 140 has been examined by means of the H I 21-cm line observations obtained with high angular resolution observations. The most interesting discoveries are the presence of huge ovoidal H I minimum spanning the velocity range +13 to +21kms−1 (WR132) and −18 to −7kms−1 (WR 140). These minima were created, very likely, by the joint action of the progenitor of both WR stars and the WR star itself. Inside each cavity, two minima are clearly discernible. The WR star is offset with respect to either the geometrical centre of the main H I void or the inner H I minima. The dual H I minimum geometry observed inside the main H I cavity, a feature also seen in the H I distribution of the ISM located close to other galactic WR stars, may be a consequence of the interaction process itself.

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