Aerosol particle sensor based on millimeter wave coherent radar with high spatial resolution

The near range measurement of water content in aerosols by coherent radar in the millimeter wave band is discussed. For bistatic radar an effective illuminated area of volume scatterers is determined taking into account the illumination tapering of the volume due to the radar power pattern shape. Procedures for the measurement of mass loading and for the calibration of the radar are outlined and calculated expressions are presented. A coherent radar in the 3 mm range and a workbench for testing the sensor are described. The proposed measurement procedure may be used if the parameters of the particle distribution law are known; otherwise a calibration procedure has to be applied.