Related papers: High Resolution Radio Astronomy Using Very Long Ba…
What is long-baseline optical/IR stellar interferometry? A few years ago, many astronomers might not have been able to answer that question properly. This is today hopefully not the case anymore, because mainstream facilities, such as the…
Very long baseline interferometry (VLBI) achieves the highest angular resolution in astronomy. VLBI measures corrupted Fourier components, known as visibilities. Reconstructing on-sky images from these visibilities is a challenging inverse…
VLBI at millimeter wavelengths (mm-VLBI) allows the detailed imaging of compact galactic and extragalactic radio sources with micro-arcsecond scale resolution, unaccessible by other observing techniques. Here we discuss the scientific…
The first very long baseline interferometry (VLBI) detections at 870$\mu$m wavelength (345$\,$GHz frequency) are reported, achieving the highest diffraction-limited angular resolution yet obtained from the surface of the Earth, and the…
At sufficiently low frequencies, no ground-based radio array will be able to produce high resolution images while looking through the ionosphere. A space-based array will be needed to explore the objects and processes which dominate the sky…
Astrometry at centimeter wavelengths using Very Long Baseline Interferometry is approaching accuracies of ~1 uas for the angle between a target and a calibrator source separated by <1 degree on the sky. The BeSSeL Survey and the Japanese…
The next generation of very long baseline interferometry (VLBI) is stepping into the era of microarcsecond ($\mu$as) astronomy, and pushing astronomy, especially astrometry, to new heights. VLBI with the Square Kilometre Array (SKA),…
The calibration and analysis of polarization observations in Very Long Baseline Interferometry (VLBI) requires the use of specific algorithms that suffer from several limitations, closely related to assumptions in the data properties that…
Very Long Baseline Interferometry is capable of measuring the gravitational delay caused by the Sun and planet gravitational fields. The post-Newtonian parameter $\gamma$ is now estimated with accuracy of $\sigma_{\gamma}=2\cdot 10^{-4}$…
The Caltech-Jodrell Bank very long baseline interferometry (VLBI) Surveys give detailed 5 GHz VLBI images of several hundred milliarcsecond (mas) radio sources, and the full width at half-maximum angular sizes of the corresponding compact…
Very Long Baseline Interferometry (VLBI) observations can provide the position of compact radio sources with an accuracy of order 50 micro-arcseconds. This is sufficient to measure the trigonometric parallax and proper motions of any object…
Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases so too does the atmospheric…
Recent advances in VLBI have led to astrometric accuracy exceeding that of the Gaia mission goals. This chapter describes some important astrophysical problems that can be addressed with sub-milliarcsecond imaging and micro-arcsecond…
I review here the present observational efforts to study parsec-scale radio jets in active galactic nuclei with very-long-baseline interferometry (VLBI) as related to the new window to the Universe opened by the LAT instrument on-board the…
Very long baseline interferometry (VLBI) technique allows us to determine positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impact of a selection of observing frequencies in a range from…
Adding VLBI capability to the SKA arrays will greatly broaden the science of the SKA, and is feasible within the current specifications. SKA-VLBI can be initially implemented by providing phased-array outputs for SKA1-MID and SKA1-SUR and…
Astronomical imaging can be broadly classified into two types. The first type is amplitude interferometry, which includes conventional optical telescopes and Very Large Baseline Interferometry (VLBI). The second type is intensity…
Long baseline radio interferometers can provide some interesting opportunities for future SETI searches. Known advantages (compared to single dishes or beam-formed arrays), include the large reduction in false-positives due to the…
We have been developing a novel interferometer formed directly between a Very Long Baseline Interferometry (VLBI) radio telescope and a Global Navigation Satellite Systems (GNSS) antenna/receiver. This interferometer is enabled by the High…
Very long baseline interferometry (VLBI) astrometry is used to determine the three-dimensional position and proper motion of astronomical objects. A typical VLBI astrometric campaign generally includes around ten observations, making it…