The Phase Pattern Of Parabolic Radar Antenna And Data Quality

Although antennas have well-known power patterns that are commonly used to understand the quality of measurements, they also have phase patterns that are difficult to obtain and are seldom discussed in the radar meteorological community. This study presents the characteristics of the antenna phase pattern of the McGill S-band radar. Phase variations in azimuth and elevation with respect to the main beam axis are obtained using high-resolution scans of an isolated ground target and of an emission source. The two-way phase pattern is relatively constant within the radar main beam, but it changes rapidly at the power minima between the main beam and the first sidelobe. The effects of this phase pattern on ground and weather targets were evaluated and were found to be much more pronounced for point targets than for distributed targets. Nevertheless, proper knowledge of the phase pattern of the radar antenna would enhance the ability to better select ground targets for radar refractivity technique and to estimate the quality of radar data.