Related papers: A Fourier method for the determination of focus fo…

The Cherenkov Telescope Array (CTA) is a future very high energy gamma-ray observatory. CTA will be comprised of small-, medium- and large-size telescopes covering an energy range from tens of GeV to hundreds of TeV and will surpass…

Cherenkov telescope cameras are not suitable to perform astrometrical pointing calibration since they are not designed to produce images of the sky, but rather to detect nanosecond atmospheric flashes due to very high-energy cosmic…

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:…

The Laguerre-Gaussian (LG) modes constitute a complete basis set for representing the transverse structure of a {paraxial} photon field in free space. Earlier workers have shown how to construct a device for sorting a photon according to…

An optimal maximum-likelihood technique for computing point-source image centroids from many, slightly offset, CCD frames is presented. The method is especially useful for measuring stellar proper motions from data taken with the Wide Field…

Focal plane arrays of bolometers are increasingly employed in astronomy at far--infrared to millimetre wavelengths. The focal plane fields and the detectors are both partially coherent in these systems, but no account has previously been…

This article presents and discusses a method for measuring the proper motions of the Galactic dwarf spheroidal galaxies using images taken with the Hubble Space Telescope. The method involves fitting an effective point spread function to…

The CERN Axion Solar Telescope (CAST) searches for solar axions employing a 9 Tesla superconducting dipole magnet equipped with 3 independent detection systems for X-rays from axion-photon conversions inside the 10 m long magnetic field.…

Fourier ptychographic microscopy (FPM) is a novel computational coherent imaging technique for high space-bandwidth product imaging. Mathematically, Fourier ptychographic (FP) reconstruction can be implemented as a phase retrieval…

Contemporary imaging air Cherenkov telescopes (IACT) for ground-based very high energy (VHE) gamma ray astronomy have prime focus optical design. Typically these telescopes have a 2-4 deg wide field of view (FoV). They use f/0.7-f/1.2…

Deep near-infrared imaging surveys allow us to select and study distant galaxies in the rest-frame optical, and have transformed our understanding of the early Universe. As the vast majority of K- or IRAC-selected galaxies is too faint for…

Telescopes, designed with semi-conductor based photo sensors, have the potential to detect Cherenkov or fluorescence light emitted by cosmic-rays in the atmosphere. Such telescopes promise a high duty cycle and efficiency in remote harsh…

The Cherenkov Telescope Array (CTA) is a future very high energy gamma-ray observatory. CTA will be comprised of small-,medium- and large-size telescopes covering an energy range from tens of GeV to hundreds of TeV and will surpass existing…

In October 2019, the central 28 m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the Medium-Sized…

Background. Relative astrometry at or below the micro-arcsec level with a 1m class space telescope has been repeatedly proposed as a tool for exo-planet detection and characterization, as well as for several topics at the forefront of…

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

We have re-examined the nature of the cluster galaxy luminosity function using the data from the Edinburgh-Durham Southern Galaxy Catalogue and the Edinburgh-Milano Redshift Survey. We derive a best fit luminosity function over the range…

Due to the limited field of view (FoV) of Cherenkov telescopes, the time needed to achieve target sensitivity for surveys of the extragalactic and Galactic sky is large. To optimize the time spent to perform such surveys, a so-called…

We introduce and experimentally implement Fourier-plane phase synchronization for optical microscopy, and demonstrate its performance with interferometric scattering microscopy. By combining a photothermal phase plate and laser beam…

This paper presents a motion-free technique for characterizing the focal length of any spherical convex or concave lens. The measurement system uses a Gaussian Beam from a Laser Source (LS), an Electronically Controlled Variable Focus Lens…