English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a method for speckle holography that is optimised for crowdedfields. Its two key features are an iterativ improvement of the instantaneousPoint Spread Functions (PSFs) extracted from each speckle frame and the(optional) simultaneous use of multiple reference stars. In this way, highsignal-to-noise and accuracy can be achieved on the PSF for each shortexposure, which results in sensitive, high-Strehl re- constructed images. Wehave tested our method with different instruments, on a range of targets, andfrom the N- to the I-band. In terms of PSF cosmetics, stability and Strehlratio, holographic imaging can be equal, and even superior, to the capabilitiesof currently available Adaptive Optics (AO) systems, particularly at shortnear-infrared to optical wavelengths. It outperforms lucky imaging because itmakes use of the entire PSF and reduces the need for frame selection, thusleading to higher Strehl and improved sensitivity. Image reconstruction aposteriori, the possibility to use multiple reference stars and the fact thatthese reference stars can be rather faint means that holographic imaging offersa simple way to image large, dense stellar fields near the diffraction limit oflarge telescopes, similar to, but much less technologically demanding than, thecapabilities of a multi-conjugate adaptive optics system. The method can beused with a large range of already existing imaging instruments and can also becombined with AO imaging when the corrected PSF is unstable.

Holographic Imaging of Crowded Fields: High Angular Resolution Imaging with Excellent Quality at Very Low Cost