High Volume Precipitation Spectrometer - 4
HVPS-4
The High Volume Precipitation Spectrometer version 4 (HVPS-4) combines four Optical Array Probes (OAPs) in a standard PMS-style canister (Figure 1a).
The four arms and dual laser beams utilize optics that coincidently image particles with both 50-µm and 150-µm resolution (Figure 1b). The higher (50-µm) resolution provides finer detail that is very useful in identifying the shapes of rain drops and larger ice particles, while the 150-µm resolution provides nearly twice the sample volume of the HVPS-3.
Figure 2 shows a photo of the HVPS-4 in the laboratory with 50-µm and 150-µm images of a 3.7 mm steel bead. It is well-known that raindrops deform into oblate spheroids in free fall (Figure 3). When sampling raindrops, images can be size-sorted so that aspect ratios from the vertical (V) and horizontal (H) orientations are analyzed to determine aspect ratio. This is especially valuable for improving particle aspect ratio and particle phase retrievals from coincident measurements using dual-polarized radar (see example in Figure 4).
HVPS-4
The High Volume Precipitation Spectrometer version 4 (HVPS-4) combines four Optical Array Probes (OAPs) in a standard PMS-style canister (Figure 1a).
The four arms and dual laser beams utilize optics that coincidently image particles with both 50-µm and 150-µm resolution (Figure 1b). The higher (50-µm) resolution provides finer detail that is very useful in identifying the shapes of rain drops and larger ice particles, while the 150-µm resolution provides nearly twice the sample volume of the HVPS-3.
Figure 2 shows a photo of the HVPS-4 in the laboratory with 50-µm and 150-µm images of a 3.7 mm steel bead. It is well-known that raindrops deform into oblate spheroids in free fall (Figure 3). When sampling raindrops, images can be size-sorted so that aspect ratios from the vertical (V) and horizontal (H) orientations are analyzed to determine aspect ratio. This is especially valuable for improving particle aspect ratio and particle phase retrievals from coincident measurements using dual-polarized radar (see example in Figure 4).