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

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