A microwave-based measuring device includes a number n of sensors, each sensor of the number n of sensors being embodied to generate associated sensor data such that, overall, a number n of items of sensor data are generated by way of the number n of sensors. A measurement variable calculation unit is embodied to calculate a number m of measurement variable values depending on the number n of items of sensor data on the basis of values of a number d of parameters. A learning unit is embodied to calculate the values of the number d of parameters on the basis of training data.