Analysis of Low Altitude Radar Echoes Observed under Clear and Partly Cloudy Conditions

摘要

Simultaneous observations of regions of disturbed index of refraction were made with high gain, high powered X-and S-band radars and two microwave refractometers. The two microwave refractometers were spaced vertically a distance of 17.5 cm and flown through the source regions of the radar echoes. Regions of disturbed index of refraction were consistently detected by the S-band radar and verified by the microwave refractometers. Additional qualitative verification of the disturbed regions was obtained by the temperature gage on the aircraft which showed a constant temperature (well mixed air) layer at the same altitude as the echoes received on the S-band radar and by the pilot who reported physical turbulence at the same altitude. The intensity of refractive index fluctuations, computed from the radar signal was found to be in good agreement with the intensity of refractive index fluctuations computed from the refractometer data. (Author)