Instrument errors due to DIFFRACTION and TIME RESPONSE are known, but there is no adequate way to de-convolve and correct measurements in the size range from about 25 to 150 mm A new particle imaging probe, the 2D-S, is fast enough to eliminate airspeed effects and has small enough (10 mm) pixels to mitigate diffraction effects.

2D-S (Stereo) Probe Laser beams illuminate dual high-speed linear arrays with 128 photodiodes each True 10 mm pixel resolution at 170 m s-1 Ability to image and time stamp particles from 10 m to 1.2 mm provides basis for separating real images from artifacts

2D-S and CAS Agree Well out to 30 mm In Cu with Drop Diameters < 100 mm (CIP and PIP Inactive)

2D-S produces actual 10 m spatial resolution, enabling it to resolve “Splashers” and “Shatterers”. An example of Splashers is shown below

Comparison of 2D-S & NCAR PMS Probes in Data from 230 RICO Rain Shafts