A ground based multi-sensor system for the remote sensing of clouds

A ground based system combining active and passive remote sensing instrumen ts from different spectral ranges has been set up at the Meteorological Ins titute in Bonn to investigate cloud processes. Currently, the sensor packag e includes a laser ceilometer, an infrared radiometer, an X-Band Radar, and a 4-channel microwave radiometer. Cloud base height and temperature, preci pitation, and the integrated quantities of water vapor and cloud liquid wat er can be measured on small time scales (less than or equal to 15 s). The s ystem will be extended in fall 1998 with a 22-channel microwave to derive p rofiles of humidity, temperature and liquid water content. A case study usi ng measurements from April 1, 1998 demonstrates the ability of the system t o characterize various types of clouds. (C) 1999 Elsevier Science Ltd. All rights reserved.