Interferometric Phase Calibration Sources in the Declination Range 0o to −30o (original) (raw)
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Interferometric Phase Calibration Sources in the Declination Range 0deg to -30deg
2002
We present a catalog of 321 compact radio sources in the declination range 0deg > delta > -30deg. The positions of these sources have been measured with a two-dimensional rms accuracy of 35 milliarcseconds using the NRAO Very Large Array. Each source has a peak flux density >50 mJy at 8.4 GHz. We intend for this catalog to be used mainly for selection of phase calibration sources for radio interferometers, although compact radio sources have other scientific uses.
Interferometric Phase Calibration Sources in the Declination Range 0° to–30°
2008
We present a catalog of 321 compact radio sources in the declination range 0 • > δ > −30 •. The positions of these sources have been measured with a two-dimensional rms accuracy of 35 milliarcseconds using the NRAO a Very Large Array. Each source has a peak flux density > 50 mJy at 8.4 GHz. We intend for this catalog to be used mainly for selection of phase calibration sources for radio interferometers, although compact radio sources have other scientific uses.
Interferometer phase calibration sources - II. The region 0o <= deltaB1950<= +20o
Monthly Notices of the Royal Astronomical Society, 1998
We present a catalogue of 781 compact radio sources in the declination range 0Њ Յ d B1950 Յ þ20Њ whose positions have been measured to an rms accuracy of about 14 mas with the Very Large Array (VLA). These sources are primarily intended for use as phase calibration sources for the Jodrell Bank MERLIN. However, they will also be suitable as phase calibrators for the VLA and can be considered as candidate phase calibrators for very long-baseline interferometry (VLBI) networks.
Interferometer phase calibration sources -- II. The region 0 <= B1950 <= +20
Monthly Notices of the Royal Astronomical Society, 1998
We present a catalogue of 781 compact radio sources in the declination range 0Њ Յ d B1950 Յ þ20Њ whose positions have been measured to an rms accuracy of about 14 mas with the Very Large Array (VLA). These sources are primarily intended for use as phase calibration sources for the Jodrell Bank MERLIN. However, they will also be suitable as phase calibrators for the VLA and can be considered as candidate phase calibrators for very long-baseline interferometry (VLBI) networks.
Interferometer phase calibration sourcesIII. The regions+ 20≤ δ B1950≤+ 35° and+ 75≤ δ B1950≤+ 90°
Monthly Notices of …, 1998
We present a catalogue of 540 compact radio sources in the declination ranges þ20Њ Յ d B1950 Յ þ35Њ and þ75Њ Յ d B1950 Յ þ90Њ, the positions of which have been measured to an rms accuracy of about 55 mas with the Very Large Array (VLA). These sources are primarily intended for use as phase calibration sources for MERLIN. However, they will also be suitable as phase calibrators for the VLA and can be considered as candidate phase calibrators for very long baseline interferometry (VLBI) networks.
Monthly Notices of the Royal Astronomical Society, 1998
We present a catalogue of 540 compact radio sources in the declination ranges þ20Њ Յ d B1950 Յ þ35Њ and þ75Њ Յ d B1950 Յ þ90Њ, the positions of which have been measured to an rms accuracy of about 55 mas with the Very Large Array (VLA). These sources are primarily intended for use as phase calibration sources for MERLIN. However, they will also be suitable as phase calibrators for the VLA and can be considered as candidate phase calibrators for very long baseline interferometry (VLBI) networks.
Inter-Element Phase Calibration in Interferometric Radiometers
2006 Ieee International Geoscience and Remote Sensing Symposium, Vols 1-8, 2006
... Ignasi Corbella ∗ , Francesc Torres ∗ , Sebastián Blanch ∗ , Serni Ribó † , Santiago Beraza ∗ , Nuria Duffo ∗ , ... Stan-dard antenna measurement systems do not use an external and independent reference signal, so different patterns do not share a common phase reference. ...
The Astronomical Journal, 2011
Space Very-Long-Baseline-Interferometry (S-VLBI) observations at high frequencies hold the prospect of achieving the highest angular resolutions and astrometric accuracies, resulting from the long baselines between ground and satellite telescopes. Nevertheless, space-specific issues, such as limited accuracy in the satellite orbit reconstruction and constraints on the satellite antenna pointing operations, limit the application of conventional phase referencing. We investigate the feasibility of an alternative technique, source frequency phase referencing (SFPR), to the S-VLBI domain. With these investigations we aim to contribute to the design of the next-generation of S-VLBI missions. We have used both analytical and simulation studies to characterize the performance of SFPR in S-VLBI observations, applied to astrometry and increased coherence time, and compared these to results obtained using conventional phase referencing. The observing configurations use the specifications of the ASTRO-G mission for their starting point. Our results show that the SFPR technique enables astrometry at 43 GHz, using alternating observations with 22 GHz, regardless of the orbit errors, for most weathers and under a wide variety of conditions. The same applies to the increased coherence time for the detection of weak sources. Our studies show that the capability to carry out simultaneous dual frequency This preprint was prepared with the AAS L A T E X macros v5.2.
Phase calibration temperature track in interferometric radiometers devoted to Earth observation
2008
MIRAS (Microwave Imaging Radiometer with Aperture Synthesis), the single payload of the ESA-SMOS mission, consists of a Y-shape interferometric radiometer basically formed by 72 receivers placed along the three arms. Crosscorrelations of the signals collected by each receiver pairs "k,j" give the samples of the so-called visibility function, V kj , which develops into a brightness temperature map by means of a Fourier transform. Therefore, phase errors in the visibility samples are directly translated into image distortion through this Fourier process. The phase is calibrated by injecting correlated noise to its receivers. A method to track phase errors due to temperature gradients has been developed in order to increase the intercalibration period, thus maximizing coverage. Due to the large size of the instrument (arms length around 4 m) and power constraints, moderate thermal swings and thermal gradients within the payload are unavoidable along the orbit. The method presented in this work shows how the visibility phase errors are decoupled into receiver phase errors that can be tracked in temperature. Experimental tests show how decoupling must deal with phase-wrapping problems and cope with the interferometric inherent problem of setting a phase reference in a temperature changing environment.
Multi-epoch radio source structure analysis of 11 calibrators at 2.3 and 8.4 GHz in the south
arXiv (Cornell University), 2023
We present the source structure analysis of 11 calibrator sources below −40° south at 2.3 (S-band) and 8.4 GHz (X-band). We used multi-epoch very long baseline interferometry source maps available in the radio fundamental catalog to analyse jet-structure variability and also used fluxes from the Goddard Space Flight Center database to see whether these two complement each other or not. Also, total fluxes from the maps were plotted with the fluxes from the database. The S/X-band light curve analysis provides a more clear picture of the structural variability at the S/X-band also indicates the possibility of the "core-shift" phenomenon. We found jet-like structures in the majority of the sources in the sample.