A. Bhatt (SRI) and J. Thayer (U. Colorado) – Rayleigh/Mie system in operation since November 1992. Operated year-round with a daylight-measurement capability. Also retrieved backscatter-ratio profiles of noctilucent clouds and polar stratospheric clouds. Data archived from 1994 - 2008 under former PI, Heinselman and subsequently through 2015 under M. McCready. Measurements ceased in 2018 due to station closure.