Evaluating a strategy for measuring deformations of the primary reflector of the Green Bank telescope using a terrestrial laser scanner

Astronomical observations in the molecule rich 3 mm window using large reflector antennas provide a unique view of Universe. To efficiently carry out these gravitational and thermal deformations have to be corrected. Terrestrial laser scanners been used measure due gravity, but not yet for measuring deformations. In this work we investigate use terrestrial scanner on primary Green Bank Telescope (GBT). Our method involves differential measurements reduce systematic effects scanner. We active surface GBT validate our explore its limitations. find that when it is possible accurately corresponding different Zernike polynomials down an amplitude 60 $\mu$m. The difference between amplitudes known those measured are $<140~\mu$m wind speed $\lesssim2$ m s$^{-1}$. From differences estimate should bring error $240\pm6~\mu$m. This suggests commercial off-the-shelf induced by gradients parabolic reflector.