On the Minimum Useful Elevation Angle for Weather Surveillance Radar Scans

The antenna beam pattern for low elevation angles is examined in relation to the radar horizon to assess the impact of base-scan elevation angle on sensitivity to near-horizon weather features, as well as its effect on reflectivity measurements and ground clutter. The results from a simple model neglecting details of surface characteristics and multipath propagation suggest that a base elevation angle of about 0.3 beamwidth above the horizon would yield near-optimum sensitivity with acceptable degradation in reflectivity observations and ground clutter.