Abstract Gravitationally induced deformation of the receiving unit of radio telescopes used for Very Long Baseline Interferometry (VLBI) distorts the observations and biases the deduced products. As this deformation acts systematically and is individual for each radio telescope. the International VLBI Service for Geodesy and Astrometry (IVS) calls for gravitational deformation investi... https://www.excellentphoto.shop/product-category/lens-accessories/