• The CPI records high-resolution (2.3 micron pixel size) digital images of particles that pass through the sample volume at speeds up to 200 m/s. CCD camera flashes up to 75 frames per second (fps), potentially imaging more than 25 particles per frame. Camera upgrades capable of bringing frame rate to nearly 500 fps.

• Real time image processing crops particle images from the full frame, eliminating blank space and compressing data by >1000:1

• CPI is designed for ummanned use, with AI parameters to optimize performance without supervision.

• CPIs sold to NASA, NCAR, University of Washington, University of North Dakota, Canadian Meteorological Society, University of Manchester, Meteorological Research Institute in Japan, Laboratoire de Meteorologie Physique (LaMP) in France, Sandia National Laboratories.

• CPIs operated in many field campaigns including:

  • NASA TRMM, NASA EOS, NASA CAMEX, NSF SHEBA, NSF Antarctica Program, NCAR/FAA MWISP, DOE ARM, Canadian Atlantic Storms Project, Canadian, Freezing, Drizzle Experiment, Alliance Icing Research Study, NSF Wave Cloud Study, Australian Emerald Project, NASA Crystal-Face, NASA MidCix, NSF RICO, and NASA CR-AVE.

CPIview: Data Analysis Program

CPI data is viewed and analyzed using a SPEC program called CPIview. The program uses a graphical interface, which makes for easy navigation through data files. The program uses IDL software. CPIview is capable of deriving perimeters around particles, calculating lengths, widths, and areas. The program also is capable of producing particle size distributions, automatic habit classifications, and time series which can be outputted in plots or asciis. As a CPI owner, updates and improvements to the program are made available to you. To learn more about the CPIview program including the formulas used for automatic classification of particles, you can read the CPIview Training Manual.

Ground-Based Operation of CPI

Since the CPI was designed for the extremes of aircraft flight—vibrations, rapid pressure changes, temperatures to -70°C, it is overwhelmingly capable in harsh ground-based research. The top panels show the CPI during the Mount Washington Icing Sensors Project (MWISP) in 1998. Mount Washington's notorious high winds and freezing drizzle created large amounts of rime (top right).
The lower panels show two CPIs set up on a platform above the surface at the South Pole. The CPIs face the prevailing winds direction toward a no-man zone thereby negating contamination from the arctic station. One CPI has a Polar Nephelometer (P-N) made by LaMP at the end of its sample tube. An exhaust fan is used to aspirate both CPIs creating a constant wind speed through the sample volume. Over one million crystals were imaged in a single week. The CPI can also be used in cloud chamber research.

Improved Imaging using CPI

CPI Theory of Operation

Instrument Specifications
(Dimensions, Weights, Diagrams)

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