A system and method for ground calibration of an aircraft weather radar (W×R) employs a calibrated W×R already flight tested on a reference aircraft to generate a ground reference map from a specific ground position on a specific heading. A W×R alignment tool receives the ground reference map and compares it to an uncalibrated ground map generated by an uncalibrated W×R in the same ground position and on the same heading. Once compared, the alignment tool determines a delta between the ground reference map and the uncalibrated ground map and determines offset values in pitch, roll, and elevation to reduce the delta to a desired operational value and make the maps nearly identical. The alignment tool then applies to offset values to the uncalibrated W×R to calibrate the W×R for operational use.