Schmidt camera Schmidt camera A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930. Some notable examples are the Samuel Oschin telescope (formerly Palomar Schmidt), the UK Schmidt Telescope and the ESO Schmidt; these provided the major source of all-sky photographic imaging from 1950 until 2000, when electronic detectors took over. A recent example is the Kepler spacecraft exoplanet finder. Other related designs are the Wright Camera and Lurie–Houghton telescope. The Schmidt camera was invented by German-Estonian optician
Hilbert–Schmidt integral operator Hilbert–Schmidt integral operator In mathematics, a Hilbert–Schmidt integral operator is a type of integral transform. Specifically, given a domain (an open and connected set) Ω in "n"-dimensional Euclidean space R, a Hilbert–Schmidt kernel is a function "k" : Ω × Ω → C with (that is, the "L"(Ω×Ω; C) norm of "k" is finite), and the associated Hilbert–Schmidt integral operator is the operator "K" : "L"(Ω; C) → "L"(Ω; C) given by Then "K" is a Hilbert–Schmidt operator with Hilbert–Schmidt norm Hilbert–Schmidt integral operators are both continuous (and hence bounded) and compact (as with all Hilbert–Schmidt operators). The concept of