  The Canadian Large Adaptive Reflector (CLAR) is a proposed prototype of a new
concept for large, filled-aperture radio telescopes. The prototype would have a
300-metre aperture, working up to frequencies of at least 1.4 GHz, and would be
equipped with a multi-beam phased array providing a field-of-view of 0.8deg at
that frequency. The largest fully-steerable radio telescope in the world, and
endowed with a large field-of-view, the CLAR will be uniquely suited for deep
spectral imaging over large areas of the sky. Conducted over a period of three
to four years, a CLAR Northern-Sky Survey would allow us to simultaneously:
survey at arcminute scales the distribution and kinematics of the faint HI in
the halo of the Milky Way and High Velocity Clouds; chart the large scale
distribution of galaxies in HI out to redshift close to 1; reveal the structure
and dynamics of the cosmic web responsible for wide-spread Lyman $\alpha$
absorption systems; image the signal of the reionization of the Universe over a
large area with resolution of 10's of arcminutes.
