Related papers: Phase Referencing and Narrow-Angle Astrometry in C…
Improved quantum sensing of photons from astronomical objects could provide high resolution observations in the optical benefiting numerous fields, including general relativity, dark matter studies, and cosmology. It has been recently…
Precise measurement of the angular deviation of an object is a common task in science and technology. Many methods use light for this purpose. Some of these exploit interference effects to achieve technological advantages, such as…
We propose bigradient phase referencing (BPR), a new radio-observation technique, and report its performance using the Japanese very-long-baseline-interferometry network (JVN). In this method, a weak source is detected by phase-referencing…
Astrometry is a powerful technique in astrophysics to measure three-dimensional positions of stars and other astrophysical objects, including exoplanets and the gravitational influence they have on each other. Interferometric astrometry is…
This paper deals with the theoretical principle and optical design of a phase-shifting telescope-interferometer. What is called a "Telescope-Interferometer" (T-I) is indeed a novel, recently proposed Wavefront Error (WFE) sensing technique,…
Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event…
The Palomar Testbed Interferometer (PTI) is a long-baseline infrared interferometer located at Palomar Observatory, California. It was built as a testbed for interferometric techniques applicable to the Keck Interferometer. First fringes…
Latest-generation spectro-interferometric instruments combine a milliarcsecond angular resolution with spectral capabilities, resulting in an immensely increased information content. Here, I present methodological work and results that…
The low infrared background and high atmospheric transparency are the principal advantages of Antarctic Plateau sites for astronomy. However, the poor seeing (between one and three arcseconds) negates much of the sensitivity improvements…
Long baseline optical interferometry and aperture synthesis using ground-based telescopes can enable unprecedented angular resolution astronomy in the optical domain. However, atmospheric turbulence leads to large, dynamic phase errors…
Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving $\pm10~\mu$as parallax accuracies at frequencies well above 10~GHz. At lower frequencies, uncompensated interferometer delays associated with…
The Sydney University Stellar Interferometer (SUSI) now incorporates a new beam combiner, called the Microarcsecond University of Sydney Companion Astrometry instrument (MUSCA), for the purpose of high precision differential astrometry of…
At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment…
Phase diffusion represents a crucial obstacle towards the implementation of high precision interferometric measurements and phase shift based communication channels. Here we present a nearly optimal interferometric scheme based on homodyne…
The next-generation space VLBI mission, VSOP-2, is expected to provide unprecedented spatial resolutions at 8.4, 22, and 43GHz. In this report, phase referencing with VSOP-2 is examined in detail based on a simulation tool called ARIS. The…
Intensity interferometry exploits a quantum optical effect in order to measure objects with extremely small angular scales. The first experiment to use this technique was the Narrabri intensity interferometer, which was successfully used in…
One major problem of phase-referencing VLBI observations are phase errors due to the unknown tropospheric zenith delay at each antenna. These errors degrade the quality of the phase-referenced image and limit the achievable astrometric…
This paper presents a non-classic approach to narrow field astrometry that offers a significant improvement over conventional techniques due to enhanced reduction of atmospheric image motion. The method is based on two key elements:…
Traditional phase-shifting interferometry technique cannot be used to measure time-varying phase distributions. But single shot techniques could resolve the problem. Many efforts have been made on the phase retrieval methods from a single…
In many areas of imaging science, it is difficult to measure the phase of linear measurements. As such, one often wishes to reconstruct a signal from intensity measurements, that is, perform phase retrieval. In this paper, we provide a…