Preliminary Evaluations of the Use of a 35 GHz Radar for Measuring Cloud Base and Cloud Top Heights

摘要

To determine the accuracy with which a vertically-pointing 35 GHz radar can detect cloud base and cloud top heights, radar data of this type, collected in earlier research projects, have been compared to cloud heights derived from aircraft, a 5.5 GHz scanning radar, and radiosondes. Comparisons with in situ aircraft observations provide the most reliable means for evaluating the accuracy of the 35 GHz radar. In the absence of precipitation, or in very light precipitation, the heights of cloud bases and cloud tops detected by the 35 GHz radar were within approx 100 m of the heights measured by aircraft flying over the radar. However, very thin clouds were not detected by the radar unless they contained some ice particles. In light to heavy precipitation, the 35 GHz radar underestimated cloud top heights and often could not detect cloud bases. (rh)