Canadian Hydrogen Intensity Mapping Experiment

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 (hydrogen intensity mapping). It also identifies radio transients 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 location 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.