相关论文: Holographic surface measurement system for the Fre…

We summarise the mathematical foundation of the holographic method of measuring the reflector profile of an antenna or radio telescope. In particular, we treat the case, where the signal source is located at a finite distance from the…

We describe the successful design, implementation, and operation of a 12 GHz holography system installed on the Robert C. Byrd Green Bank Telescope (GBT). We have used a geostationary satellite beacon to construct high-resolution…

We present a technique for the accurate estimation of large-scale errors in an antenna surface using astronomical sources and detectors. The technique requires several out-of-focus images of a compact source and the signal-to-noise ratio…

Near-field radio holography is a common method for measuring and aligning mirror surfaces for millimeter and sub-millimeter telescopes. In instruments with more than a single mirror, degeneracies arise in the holography measurement,…

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic…

Large deployable antennas with a mesh surface woven by fine metal wires are an important technology for communications satellites and space radio telescopes. However, it is difficult to make metal mesh surfaces with sufficient…

We describe phase-retrieval holography measurements of the 100-m diameter Green Bank Telescope using astronomical sources and an astronomical receiver operating at a wavelength of 7 mm. We use the technique with parameterization of the…

We present a concept of a millimeter wavefront sensor that allows real-time sensing of the surface of a ground-based millimeter/submillimeter telescope. It is becoming important for ground-based millimeter/submillimeter astronomy to make…

In radio astronomy, holography is a commonly used technique to create an image of the electric field distribution in the aperture of a dish antenna. The image is used to detect imperfections in the reflector surface. Similarly, holography…

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution,…

Reflective imaging systems form an important part of photonic devices such as spectrometers, telescopes, augmented and virtual reality headsets or lithography platforms. Reflective optics provide unparalleled spectral performance and can be…

Astronomers working with faint targets will benefit greatly from improved image quality on current and planned ground-based telescopes. At present, most adaptive optic systems are targeted at the highest resolution with bright guide stars.…

The optical structure of several AGN has been studied using the Fine Guidance Sensors (FGS) on the Hubble Space Telescope (HST). The FGSs are interferometric devices which can resolve structure on scales of 20 milliarcsecs or less and hence…

The Prime-Cam instrument on the Fred Young Submillimeter Telescope (FYST) is expected to be the largest deployment of millimeter and submillimeter sensitive kinetic inductance detectors to date. To read out these arrays efficiently, a…

In this work, we present the design and manufacturing of the two multi-mode antenna arrays of the COSMO experiment and the preliminary beam pattern measurements of their fundamental mode compared with simulations. COSMO is a cryogenic…

In the construction of a space radio telescope, it is essential to use materials with a low noise factor and high mechanical robustness for the antenna surface. We present the results of measurements of the reflection performance of two…

A hemispherical multilayer wide-band (7-13 GHz) band-pass frequency selective surface (FSS) is reported. A new design technique based on a Goldberg discretization and unit cell scaling technique is introduced to accommodate the curved…

The Large Synoptic Survey Telescope (LSST) will use an active optics system (AOS) to maintain alignment and surface figure on its three large mirrors. Corrective actions fed to the LSST AOS are determined from information derived from 4…

Fourier transform (FT) spectroscopy is a versatile technique for studying the infrared (IR) optical response of solid-, liquid-, and gas-phase samples. In standard FT-IR spectrometers, a light beam passing through a Michelson interferometer…

We simulate the scientific performance of the Wide-Field Infrared Survey Telescope (WFIRST) High Latitude Survey (HLS) on dark energy and modified gravity. The 1.6 year HLS Reference survey is currently envisioned to image 2000 deg$^2$ in…