Interpolation of Operational Radar Data to a Regular Cartesian Grid Exemplified by Munich’s Airport Radar Configuration

Kurzfassung

Two methods for avoiding errors in the interpolation of operational radar data to a regular grid are presented. The issue is the interpolation of radial velocity and the subsequent estimation of horizontal wind components. It is shown how a vertical gradient of the horizontal wind in combination with gaps of data between scans with different elevation angles affect the interpolation. Simulated radar data for the radar configuration covering the Munich airport in southern Germany are used for illustration. The origin of the abovementioned errors is explained using simplified wind fields. With wind fields generated by the German nonhydrostatic atmospheric prediction model COSMO-DE, the effectiveness of the methods is presented. Both methods contribute to a reduction in interpolation error—by 44% and 35%, respectively—compared to a standard interpolation scheme used for many operational radar configurations.