The NASA Goddard Space Flight Center (GSFC) and its partners have broad experience in the alignment of flight optical instruments and spacecraft structures. Over decades, GSFC developed alignment capabilities and techniques for a variety of optical and aerospace applications. In this paper, we provide an overview of a subset of the capabilities and techniques used on several recent projects in a toolbox format. We discuss a range of applications, from small-scale optical alignment of sensors to...
Topics: Blake, Peter N., Bos, Brent J., Casto, Gordon V., Coulter, Phillip, Eichhorn, William L., Genesis...
A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical...
Topics: NASA Technical Reports Server (NTRS), OPTICAL EQUIPMENT, LIGHT BEAMS, ALIGNMENT, RANGE FINDERS,...
This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics...
Topics: NASA Technical Reports Server (NTRS), DISTANCE MEASURING EQUIPMENT, OPTICAL PATHS, TELESCOPES,...
A method for corrections of measurements of points of interests measured by beams of radiation propagating through stratified media including performance of ray-tracing of at least one ray lunched from a metrology instrument in a direction of an apparent point of interest, calculation a path length of the ray through stratified medium, and determination of coordinates of true position of the point interest using the at least one path length and the direction of propagation of the ray.
Topics: NASA Technical Reports Server (NTRS), BEAMS (RADIATION), CORRECTION, OPTICAL RADAR, RAY TRACING,...
The NASA Goddard Space Flight Center (GSFC) and its partners have broad experience in the alignment of flight optical instruments and spacecraft structures. Over decades, GSFC developed alignment capabilities and techniques for a variety of optical and aerospace applications. In this paper, we provide an overview of a subset of the capabilities and techniques used on several recent projects in a \"toolbox\" format. We discuss a range of applications, from small-scale optical alignment...
Topics: Blake, Peter N., Bos, Brent J., Coulter, Phillip, Eichhorn, William L., Genesis Engineering...
Lidar is a useful tool for taking metrology measurements without the need for physical contact with the parts under test. Lidar instruments are aimed at a target using azimuth and elevation stages, then focus a beam of coherent, frequency modulated laser energy onto the target, such as the surface of a mechanical structure. Energy from the reflected beam is mixed with an optical reference signal that travels in a fiber path internal to the instrument, and the range to the target is calculated...
Topics: NASA Technical Reports Server (NTRS), OPTICAL RADAR, OPTICAL MEASUREMENT, METROLOGY, RADAR...
The James Webb Space Telescope science instruments are in the final stages of being integrated into the Integrated Science Instrument Module (ISIM) element. Each instrument is tied into a common coordinate system through mechanical references that are used for optical alignment and metrology within ISIM after element-level assembly. In addition, a set of ground support equipment (GSE) consisting of large, precisely calibrated, ambient, and cryogenic structures are used as alignment references...
Topics: NASA Technical Reports Server (NTRS), OPTICAL MEASUREMENT, METROLOGY, INSTRUMENT ERRORS, FLIGHT...
