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We describe new results from the semiconductor-laser tracking frequency gauge, an instrument that can perform sub-picometer distance measurements and has applications in gravity research and in space-based astronomical instruments proposed…
The scientific motivation is reviewed for a next generation radio observatory operating at frequencies between about 200 MHz and 2 GHz with about 2 orders of magnitude greater sensitivity than that which is currently available, together…
A new radio spectrometer, CALLISTO, is presented. It is a dual-channel frequency-agile receiver based on commercially available consumer electronics. Its major characteristic is the low price for hardware and software, and the short…
Millimter (mm) frequencies are primarily sensitive to thermal emission from layers across the stellar chromosphere up to the transition region, while metrewave (radio) frequencies probe the coronal heights. Together the mm and radio band…
We present observational constraints on the solar chromospheric heating contribution from acoustic waves with frequencies between 5 and 50 mHz. We utilize observations from the Dunn Solar Telescope in New Mexico complemented with…
Nulling interferometry is a technique providing high angular resolution which is the core of the space missions Darwin and the Terrestrail Planet Finder. The first objective is to reach a deep degree of starlight cancelation in the range 6…
We present an absolute distance measurement interferometer based on a two wavelength interferometer and a variable synthetic wavelength technique. The wavelength scanning range was 12 GHz, realized with a phase accuracy of 1.0 m{\lambda} by…
Detection of infrared light is central to diverse applications in security, medicine, astronomy, materials science, and biology. Often different materials and detection mechanisms are employed to optimize performance in different spectral…
A laboratory prototype spectral/spatial interferometer has been constructed to demonstrate the feasibility of the double Fourier technique at Far Infrared (FIR) wavelengths (0.15 - 1 THz). It is planned to use this demonstrator to…
Some 15% of solar flares having a soft X-ray flux above GOES class C5 are reported to lack coherent radio emission in the 100 - 4000 MHz range (type I - V and decimetric emissions). A detailed study of 29 such events reveals that 22 (76%)…
In this paper, we use a highly sensitive telescope to characterize solar X-ray transients ranging from microflares in active regions down to weakly energetic brightenings in the quiet Sun. X-rays are closely linked to the initial energy…
We present 36 observations of 17 visual binaries of moderate separation (range from 0.15'' to 0.79'') made with the 50 cm Cassegrain telescope of the Jagiellonian University in Cracow. The speckle interferometry technique was combined with…
A small flare ribbon above a sunspot umbra in active region 12205 was observed on November 7, 2014, at 12:00 UT in the blue imaging channel of the 1.5 m GREGOR telescope, using a 1 A Ca II H interference filter. Context observations from…
The explanation of the coronal heating problem potentially lies in the existence of nanoflares, numerous small-scale heating events occuring across the whole solar disk. In this paper, we present the first imaging spectroscopy X-ray…
Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised. The lower chromosphere contains neutral atoms, the existence of which greatly increases the efficiency of the damping of waves due to…
A new method of angle estimation of multiple targets using a distributed interferometric antenna array and wideband space-time modulation is presented in this work. Interferometric array measurements of angle of arrival are generally…
Measurement of interferometric parameters values is affected by phase disturbance due especially to atmospheric turbulences. Algorithms of fringe sensing, aimed at fringe parameters identification, are based on interferometric models that…
We present the successful measurement of the squared visibility of Sirius at a telescope separation of 3.3 m using small 0.25 m Newtonian-style telescopes in an urban backyard setting. The primary science goal for small-scale intensity…
We investigate the possibility of observing very small amplitude low frequency solar oscillations with the proposed laser interferometer space antenna LISA. For frequencies below $\sim 2\times 10^{-4}$ Hz the dominant contribution is from…
Space-based interferometric gravitational wave instruments such as the ESA/NASA Laser Interferometer Space Antenna (LISA) observe gravitational waves by measuring changes in the light travel time between widely-separated spacecraft. One…