Thermoelastic Measurements on Reflectors for Telecommunication Satellites 1999-01-2132

The standard method of the application of videogrammetry during space simulation tests will be summarized. Some improvements, test setups and solved problems will be described. For a videogrammetry measurement a number of pictures are needed. The different views of the test article can be achieved by several methods Test setups with a rotating reflector or a camera on a rotating arm will be presented. If the distortion of the front and the rear side has to be measured simultaneously, two cameras one with view from the top side and an other with view from the bottom side was used. The tilt of the mounting interface with respect to the shell can be measured by means of an additional sophisticated structure attached to the rear interface.

Special precaution has to be taken to reach the extreme temperatures in a reasonable time and with modest effort. A number of tests were performed. The distortion of reflectors with a diameter from 500 mm to 3500 mm and antenna towers was measured and an accuracy of better than 10μm per one meter in diameter was achieved.