PHIPS
Particle Habit Imaging and Polar Scattering Probe

The Particle Habit Imaging and Polar Scattering (PHIPS) probe is an in situ airborne cloud probe used to analyze particle shape, size, and habit. It features a high-resolution stereomicroscopic imager and a single-particle polar nephelometer. The particle imager captures images of the same cloud particle from two different angles at a resolution of 2 μm. The nephelometer measures light scattering of single particles across 20 angles from 18 to 170 degrees, with an angular resolution of 1 degree for forward scattering and 8 degrees for side and backscattering. PHIPS can measure particle sizes ranging from 50 to 700 μm for ice particles and 100 to 700 μm for water droplets. It has a field of view of approximately 3 x 2 mm and a sampling frequency of 0.7 seconds.