CALIBRATION (RADAR)

as well as de-cluttering for permanent echoes, and other adjustments, rainfall radar returns are calibrated (in real-time) against a network of telemetering rain gauges. This means of course that if the return is over areas without rain gauges (e.g. the sea), over-reading can occur, and caution is needed in blindly following radar imagery to assess rainfall rates/accumulations for this reason.