One or more radar sensors coupled to a vehicle receive readings during a calibration time period. Each radar sensor receives data covering a field of view of the sensor, which may be split into angle-based bins. A noise-reducing filter (e.g., median filter) may be applied. A function is generated by processing raw radar cross section (RCS) returns into values plotted against angles compared to the direction that the sensor is facing. The function may be smoothed. Radar sensor measurements captured after calibration are corrected using the function, for example by automatically subtracting or dividing amounts corresponding to the function.