Turbulence Measurements During Spring of 1994 at Apache Point Observatory.

Abstract : Optical turbulence measurements taken using the Atmospheric Turbulence Measurement and Observation System (ATMOS) and an acoustic sounder at the newly established Apache Point Observatory (APO) are presented for spring 1994. APO is located at 9200 ft MSL about 18 mi south of Cloudcroft, NM. The ATMOS is an optical device for determining seeing conditions by measuring angle-of-arrival fluctuations through two subapertures of a telescope. This optical arrangement, utilizing a differential measurement technique, eliminates errors caused by tracking, vibration, and wind loading. Results include all r(o) measurements, the surface wind measured at nearby Sacramento Peak, time-height displays of sodar observations, and wind and Cn(2) profile measurements taken with a 50-MHz radar located in the Tularosa Basin. A method under development to predict optical turbulence at APO is briefly discussed. (AN)