The proposal has strong intellectual merit. The PI team is well-experienced in the needed AO expertise and robot-AO in particular. A new generation of precision astrometry has merit in various research topics from dark matter to extra-solar planets. The project is well-planned and the necessary resources are in hand.

In the context of the five review elements, please evaluate the strengths and weaknesses of the proposal with respect to broader impacts.

The study is consistent with the encouragement by ASTRO-2010 for new OIR astronomy and to exploit the unique advantages of sites in Antarctica. The commissioning will train a graduate student in AO engineering/science and there is a real need in the field with the next generation of AO that will be required for even larger aperture telescopes to come. This proposed study would involve undergraduate students.

Please evaluate the strengths and weaknesses of the proposal with respect to any additional solicitation-specific review criteria, if applicable

Summary Statement

The PI team proposes a feasibility study for a robotic 2.4 m telescope at the South Pole for astrometry. The South Pole Robo-AO Infrared Telescope (SPRITE) would conduct high-precision, relatively short exposure astrometric observations of globular clusters, halo streams and hypervelocity stars to map the distribution of dark matter, as well astrometry for extra-solar planets, etc. They have made impressive astrometric observations on the 200' Palomar telescope, but plan for much better results with SPRITE. They propose to utilize the Robo-AO system on the Palomar 60' telescope. As for location in Antarctica, they wish to take advantage of the thinness of the turbulent boundary layer induced by katabatic winds.

The PI team proposes to investigate the requirements for winterized telescope design drawing on the work of others at Antarctica, and doing things like employing low expansion glass. They will cold test components on campus at Caltech. Robotic operation will take advantage of the Robo-AO software, but will require a new interface that will be ultimately sought from some vendor for SPRITE. After successful feasibility study they would propose to NSF-OPP as a mid-sized project.

The PI team is well-experienced for the work they propose. They do not plan to locate SPRITE at DOME C, which they argue is not essential for SPRITE, so they should have a wider choice of sites.

This is an strong proposal that could lead to a significant advance in 'synoptic' astrometry'