Astronomical Data Analysis Software and Systems VII ASP Conference Series, Vol. ... Integrating the ZGSC and PPM at the Galileo Telescope for On­line Control of Instrumentation F. Pasian, P. Marcucci, M. Pucillo and C. Vuerli Osservatorio Astronomico di Trieste, 34131 Trieste, Italy Email: pasian@ts.astro.it O. Yu. ... The two CD­ROMs make for relatively slow access times. ... The ZGSC and PPM catalogs will be accessed by means of the GUIDARES and XSKYMAP for a number of di#erent purposes including: . ...

... A non-linear relationship is observed between the sky brightness on clear and overcast nights, with a change in behavior near the rural to urban landuse transition. ... The great variation in skyglow radiance observed from site-to-site and with changing meteorological conditions underlines the need for a long-term international monitoring program. he introduction of artificial light has caused an unprecedented disruption to the nighttime environment over large areas of the Earth. ... Data processing...