Note: Computer controlled rotation mount for large diameter optics

Modified Physical Optics Approximation for RCS Calculation of Electrically Large Objects with Coated Dielectric

The Radar Cross Section of a target plays an important role in the detection of targets by radars‎. ‎This paper presents a new method to predict the bistatic and monostatic RCS of coated electrically large objects. ‎The bodies can be covered by lossy electric and/or magnetic Radar Absorbing Materials (RAMs)‎. ‎These materials can be approximated by the Fresnel reflection coefficients‎. ‎The pro...

Keck Adaptive Optics Note

Development of a Computer-Controlled Polishing Process for X-Ray Optics

The future X-ray observatory missions require grazing-incidence x-ray optics with angular resolution of < 5 arcsec halfpower diameter. The achievable resolution depends ultimately on the quality of polished mandrels from which the shells are replicated. With an aim to fabricate better shells, and reduce the cost/time of mandrel production, a computercontrolled polishing machine is developed for...

Applications of computer-generated holograms for interferometric measurement of large aspheric optics

Interferometric optical testing using computer-generated holograms (CGH’s) has proven to give highly accurate measurements of aspheric surfaces. New applications of CGH interferometry were developed to support the fabrication of the large, steep mirrors required by the next generation ground-based telescopes. A new test to certify null correctors was designed and implemented that uses small CGH...

Wavefront sensorless adaptive optics for large aberrations.

In some adaptive optics systems the aberration is determined not by using a wavefront sensor but by sequential optimization of the adaptive correction element. Efficient schemes for the control of such systems are essential if they are to be effective. A scheme is introduced that permits the efficient measurement of large amplitude wavefront aberrations that are represented by an appropriate se...