Three-View Cloud Particle Imager

Short Name or Variable Name:

3V-CPI

HAIS Instrument:

Yes

Manufacturer or Builder:

TABS

Description

Model:

none

Measurements Provided:

Images of hydrometeors, sizes, shapes, and concentrations of hydrometeors with sizes from about 10 um to a few mm. Images of a subset of the hydrometeors are recorded in more than one of the three systems.

General Description:

The Three-View Cloud Particle Imager (3V-CPI) is a combination of three imaging instruments. Two of them comprise a 2D-S instrument, in which two 2D probes image particles as they pass through beams that are oriented orthogonally to each other and the airflow. If particles also lie in the intersection of the sensitive areas of the two beams, they are seen by both 2D probes. In that case, the CPI is triggered to take a high-resolution picture, via a briefly illuminated high-resolution imaging array, to provide a third image at high resolution. The optical arrangement is illustrated in the following figure:
- The 3V-CPI mounted on a C-130 pod (left), and on a pylon under the GV wing with a protective shroud (right)

3V-CPI has flown on both the GV and C-130, as pictured above. The probe is particularly suited to imaging ice crystals, but also provides good detection of other hydrometeors including large cloud droplets, drizzle and small rain drops, and precipitation particles.

Measurement Characteristics:

Not Yet Available or Unknown

Calibration Methods:

Size calibration is checked with a spinning disk (a disk with images on it that is rotated rapidly through the sensing volume). Optical alignment is also needed but is a specialized process best done only occasionally.

History of Significant Changes:

None since delivery, although the software as changed and continues to change (as of 2013).

Example(s) of Measurement

CPI images:

Screenshot of 3VCPIView, with particle size distributions from a DC3 flight:

Contacts

Lead Contact:

Sarah Woods

Alternate Contact:

Mike Reeves

Status/Plans

Current Location:

Not Available

Operational Status:

Decommissioned ( no longer requestable )

Problems - Documentation:

We have not received the documents specified as deliverables in the contract and need to receive those from SPEC. This includes appropriate documentation for the processing programs, although some preliminary versions of users manuals have been provided.

Data

EOL Deployments:

Lifecycle

Date Acquired:

January, 2010