The Canadian Hydrogen Intensity Mapping Experiment (CHIME)
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a radio interferometer which will map the 21 cm line of neutral Hydrogen over the cosmological redshift range of 0.8 to 2.5. It consists of four cylindrical reflector antennas, each 100 metres long and 20 metres wide. Each cylinder will have 256 dual-polarisation feed antennas spaced along the focal line. Data from this telescope will be used to measure baryon acoustic oscillations, giving a length scale that can be used to measure the expansion history of the universe.