Results 241 to 250 of about 36,135 (283)

Precision Surveying Using Radio Interferometry

Journal of the Surveying and Mapping Division, 1978
The application of Very long baseline Interferometry (VLBI) to surveying is reviewed. An examination of the error budget for the VLBI observing system in use by the GSFC/HO/MIT VLBI team is presented, and methods for decreasing the effects of the various errors sources are reviewed. Results from recent VLBI experiments are presented. These results show
James W. Ryan, Jill J. Wittels, Alan R. Whitney, Irwin I. Shapiro, Alan E.E. Rogers, Douglas S. Robertson, Chopo Ma, Curtis A. Knight, Hans F. Hinteregger, Charles C. Counselman, William D. Cotton, Brian E. Corey, Robert Coates, Thomas A. Clark   +13 more
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Compressed sensing and radio interferometry

2015 23rd European Signal Processing Conference (EUSIPCO), 2015
Radio interferometric imaging constitutes a strong ill-posed inverse problem. In addition, the next generation radio telescopes, such as the Low Frequency Array (LOFAR) and the Square Kilometre Array (SKA), come with an additional direction-dependent effects which impacts the image restoration.
Jiang, M., Girard, J. N., Starck, J.-L., Corbel, S., Tasse, C.   +4 more
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Radio Interferometry From Space Platforms

SPIE Proceedings, 1984
While current VLBI observations are limited in their resolution by the earth diameter magnitude, which is the largest antenna separation available, as well as in their information content, because of the small number of antennas in use at a given time, the extension of VLBI to include one or more antennas in space will relieve both constraints and help
D. H. Roberts, S. H. Morgan, B. F. Burke, J. F. Jordan, R. A. Preston, E. C. Hamilton   +5 more
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Astronomical radio interferometry

Nature Reviews Methods Primers, 2023
Yoshiharu Asaki, Belén Alcalde Pampliega, Philip G. Edwards, Satoru Iguchi, Eric J. Murphy   +4 more
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General relativity and radio interferometry

The Physics Teacher, 1976
A summary is given of the radiowave bending experiment conducted at NRAO to check the validity of Einstein’s General Relativity theory ...
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Photonic radio frequency phase-shift amplification by radio frequency interferometry

Optics Letters, 2015
We present a new technique for radio frequency (RF) phase-shift amplification based on RF interferometry and demonstrate it in an optical system. A striking feature of this amplifier is that the input phase noise is not amplified together with the input phase signal, so the phase sensitivity improves with higher phase amplification.
Moshe Ben, Ayun, Arye, Schwarzbaum, Seva, Rosenberg, Monika, Pinchas, Shmuel, Sternklar   +4 more
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Regularization methods in radio interferometry

Radiophysics and Quantum Electronics, 2007
The problem of image retrieval in radio interferometry is a classical example of an ill-posed problem. In this paper, we consider a new approach to the radio-interferometric imaging based on regularization, which is computationally more flexible. A new type of a weighting function suitable for managing the interferometer antenna pattern is obtained ...
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Radio and Optical Interferometry

2004
This lecture will cover the basics of astronomical interferometers as imaging devices. The basic response of such an instrument to celestial signals is covered as well as the relationships between what can be measured and what is desired, i.e. the brightness distribution on the sky. This topic is covered in much detail in [11], [10].
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Geodesy by Radio Interferometry

1977
By the use of radio-interferometric observations of extragalactic radio sources it is possible to determine all three components of an interferometer “baseline” vector, which extends from one radio antenna to another, with respect to an inertial coordinate system.
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Radio Interferometry of Discrete Sources

Proceedings of the IRE, 1958
Salient features of the theory and practice of radio interferometry are presented with special attention to assumptions and to the specifically two-dimensional aspects of the subject. The measurable quantity on an interferometer record is defined as complex visibility by generalization from an analogous quantity in optical interferometry.
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