Citation
Abstract
This article describes the use of a pupil mask and a charge-coupled device (CCD) camera with stellar sources to characterize the optical performance of a 1-meter telescope, built for JPL by the firm Brashear LP of Pittsburgh, Pennsylvania, after the telescope was permanently installed in JPL’s Optical Communications Telescope Laboratory (OCTL) at the Table Mountain Observatory. A total of twenty-two 1-minute exposures of a 6th magnitude star were recorded over a span of 1 hour on the night of June 3, 2004, UTC. “Seeing” was estimated at 1 arcsecond or better. Analyzed by methods described herein, the method yields Zernike wavefront aberration coefficients having an average standard deviation of about ±0.04 wave at 633 nm per individual frame for the low-order aberrations considered (x-tilt, y-tilt, defocus, X-astigmatism, T-astigmatism, x-coma, and y-coma). The formal standard deviation of the mean, estimated by dividing by (N − 1), where N = 22 frames, thus approaches ±0.01 wave. This compares favorably with the accuracy achieved by interferometry in factory tests of the OCTL telescope. The root-sum-square (rss) sum of astigmatism and coma is shown to be in the neighborhood of 0.13 wave rootmean-square (rms). Of this total, about 0.09 wave rms is due to coma that could, in principle, be corrected by re-centering the secondary by 0.002 inch (50 µm).
Keywords
Details
- Volume
- 42-161
- Published
- May 15, 2005
- Pages
- 1–14
- File Size
- 737.7 KB