Development of a device for measuring turbulence in the air above telescopes that observe the sun

Measuring the turbulence in the atmosphere at different altitudes or ""heights"" above telescope observing sites allows astronomers to correct for the blurring of images that this turbulence produces. This blurring occurs when observing stars and galaxies at night, but also when observing the star nearest to the earth, the Sun, during the day. The principal investigator (PI) of this proposal, along with a graduate student and a post-doctoral scholar, will build a portable unit that can be used to measure the turbulence ""profile"" above any observatory. The instrument will be used specifically with telescopes that observe the sun. The device will be tested at solar telescopes at the Sacramento Peak and Kitt Peak observatories, and eventually at the U.S.'s newest facility, the Daniel K. Inouye Solar Telescope, DKIST, in Hawaii. The PI's institution, California State University Northridge (CSUN), is an undergraduate teaching institution with modest internal support for research; it is also a Hispanic Serving Institution (HSI) due to the large fraction of under-represented minority undergraduates served.

The PI aims to develop a portable seeing profiler for use at solar observatories. The device will measure the profile of atmospheric turbulence as a function of altitude (up to 30 km) above the observing site. The instrument comprises off-the-shelf components and two small, 10 cm telescopes that can be transported to any solar observatory. Knowledge of the atmospheric seeing conditions is crucial to the performance of solar adaptive optics (AO) systems. Existing seeing profiler techniques use large telescopes with diameters of 1.2 meters or more and need access to the sky over many months. The low-cost portable system proposed here should thus alleviate some of these issue. Currently, relatively little is known about the daytime seeing profile on many of the world's solar telescope sites. A prototype device has already been built and tested; for the new instrument modest funding is requested to purchase mechanical parts and two scientific CMOS cameras, to assemble the equipment, to develop the associated software, and finally to test the set-up at Sacramento Peak and at the DKIST site in Hawaii.