公开(公告)号：US3578975A

公开(公告)日：1971-05-18

申请号：US3578975D

申请日：1968-06-14

Applicant: PERKIN ELMER CORP

Inventor： WHEELER CHESTER C

IPC: G01S3/787 ,  G02B27/40 ,  G01B9/00 ,  G01J1/26

CPC classification number: G02B27/40 ,  G01S3/787

Abstract: Guiding and focusing errors in a stellar telescope are detected automatically using photoelectric techniques. Light from a guidestar, collected by the telescope, is directed out of the telescope as a converging focusable beam and impinges on a highspeed chopping element. Guiding errors are detected by measuring the intensity of the emerging chopped light. An AC component in the output signal indicates an error. Focusing errors are detected by measuring the intensity of the emerging chopped light after it strikes and is partly blocked by a knife edge positioned where the focus should occur. An AC component in the output signal indicates an error. Both output signals are either read on meters or fed into servosystems which move portions of the telescope to compensate for the errors.