05 June 30 Holography Focus and Centration Measurements Ant X Y Z -------------------------------- 8R 23 -14 68 cm 8L -20 14 72 17R 24 4 54 17L -26 -13 54 ---------------------------------- RMS errors are about 4 cm in X and Y, and 1 cm in Z. N.B. the large difference in focus for antennas 8 and 17. This corresponds to about one tenth lambda/D. The a priori focus error for a fully retracted sub-reflector is 50 cm.