Jerry R. Wiant

High Precision Lunar Tracking For Laser Ranging

Laser ranging to lunar surface retro-reflectors has provided a valuable source of data for the investigation of the lunar orbit, the earths orientation in space, general relativity, and many other aspects of solar system dynamics.1,2,3 Due to the moons relatively large distance, and the requirement to keep the beam from the relatively low-power laser very narrow, acquiring this data type requires very accurate telescope pointing and tracking capabilities. The nominal requirement is to keep the telescope on target within approximately 1 arc-sec of its predicted location for at least several minutes. An expansion of this requirement and the methods we have used to accomplish this high precision pointing are presented. Difficulties encountered and a few future goals of automating the McDonald station are also discussed.

A Portable Millisecond‐Integration‐Time Photoelectric Photometer

Portable equipment for recording millisecond‐integration‐time photoelectric photometric data is described. Digital data are reliably recorded on standard 6.35 mm audio grade magnetic tape via a quadradial audio grade tape deck. The system is designed specifically for recording lunar occulations of stars, but the data recording technique is independent of the data source. Recovery of the data is made via minicomputer.