The Canadian Hydrogen Intensity Mapping Experiment (CHIME,
sometimes further abbreviated as CH)
is a radio telescope in British Columbia, Canada,
originally to map the distribution of neutral hydrogen
in the redshift range of 0.8 to 2.5 (hydrogenintensity mapping).
It also identifies radiotransients such as fast radio bursts (FRBs).
It consists of four cylindrical reflectors in a static
configuration, i.e., a cylindrical telescope.
It views half the sky by sweeping out a
longitudinal arc over the course of the Earth's rotation.
The initial aim was to observe the 21-cm line
redshifted to its frequency range of 400 MHz to 810 MHz,
and it began science observations in 2018.
This effectively recorded FRBs, and their detection and observation
has become a substantial part of its mission, termed CHIME/FRB.
In 2021, a CHIME/FRB Catalog of over 500 FRBs was offered.
The Canadian Hydrogen Observatory and Radio-transient Detector
(CHORD) is a plan for a substantial upgrade to CHIME to improve its
ability to observe radio transients. It would add a substantial
array of 512 6-meter dish telescopes at the current CHIME location as well
as cylindrical and dish telescopes at other locations to serve
as outriggers, to provide much better information regarding the
localization of the transient radio sources within the celestial sphere.
It aims at a wider bandwidth than the existing CHIME (300-1500 MHz).
The Deep Dish Development Array (D3A) is a test array for
the dish telescopes.