  Results of the initial calibration of the Ultra-Violet Imaging Telescope
(UVIT) were reported earlier by Tandon et al. (2017). The results reported
earlier were based on the ground calibration as well as the first observations
in orbit. Some additional data from the ground calibration and data from more
in-orbit observations have been used to improve the results. In particular,
extensive new data from in-orbit observations have been used to obtain (a) new
photometric calibration which includes (i) zero-points (ii) flat fields (iii)
saturation, (b) sensitivity variations (c) spectral calibration for the near
Ultra Violet (NUV; 2000 - 3000 Angstroms) and far Ultra-Violet (FUV; 1300 -
1800 Angstroms) gratings, (d) point spread function and (e) astrometric
calibration which included distortion. Data acquired over the last three years
show continued good performance of UVIT with no reduction in sensitivity in
both the UV channels.
