  Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of
Far Ultra Violet (FUV; 130 to 180 nm), Near Ultra Violet (NUV; 200 to 300 nm)
and Visible band (VIS; 320 to 550nm) imagers. ASTROSAT is a first multi
wavelength mission of INDIA. UVIT will image the selected regions of the sky
simultaneously in three channels & observe young stars, galaxies, bright UV
Sources. FOV in each of the 3 channels is about 28 arc-minute. Targeted angular
resolution in the resulting UV images is better than 1.8 arc-second (better
than 2.0 arc-second for the visible channel). Two identical co-aligned
telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of 375 mm
diameter) collect the celestial radiation and feed to the detector system via a
selectable filter on a filter wheel mechanism; gratings are available in the
filter wheels of FUV and NUV channels for slit-less low resolution
spectroscopy. The detector system for each of the 3 channels is generically
identical. One telescope images in the FUV channel, and other images in NUV and
VIS channels. One time open-able mechanical cover on each telescope also works
as Sun-shield after deployment.We will present the optical tests and
calibrations done on the two telescopes. Results on vibrations test and
thermo-vacuum tests on the engineering model will also be presented.
