Fido-Phi-Pi is a modification of Fido-Phi, designed to develop an in situ 3-dimensional stereo particle image velocimetry system. The data collected with Fido-Phi-Pi is analyzed to better our knowledge of water velocities and turbulent flows in the ocean. Along with understanding the physical structure in the upper 100m of the ocean, Fido-Phi-Pi also assists in profiling detailed view of micro scale phytoplankton distributions. The system has one vertical sheet of laser light (by Melles Griot) serving as the image plane and two Cooke SensiCam QE CCD cameras on either side of the laser sheet. The laser light is used to induce the chlorophyll from the microstructures, which lights as fluorescence. The camera is equipped with special filters to image this fluorescence, capturing images of particles in the laser sheet at a frame rate of 8 Hz. By positioning both camera lenses so that its image plane is parallel to the plane of the laser sheet, it allows us to capture the 2-dimensional in-plane particle displacements. To record the 3rd dimension displacement, both camera lenses will be oriented obliquely (45° during deployment) to the plane of laser sheet. This allows us to capture the movement of particles entering and exiting the plane.
The system is broken down into four major components: camera, laser, sensors, and frame. The camera, laser, and sensor components are contained in separate pressure housings. The sensor component consists of a PC with National Instruments interface boards running LabVIEW. The sensor component monitors depth, heading, pitch, roll, and vital statistics (temperature and humidity) of all three housings in addition to controlling an automated weight release system. The camera component is a slightly modified version of the LUMIS system and consists of a PC with Cooke PCI interface boards, also running LabVIEW, and a highly sensitive camera. The laser component consists of a high power Diode Pumped Solid State 532nm laser with a custom lens. The sensor and camera components are connected via Ethernet and are both individually accessible from an external computer.Fido-Phi-Pi is 2.5m in diameter, 3m tall and weighs 1000kg in air, 2 kg in water.
- Principal Investigators: Jules Jaffe and Peter Franks
- Chief Engineer: F. Simonet
- Mechanical Engineer: Fred Ulhman - Hydrodynamic aspects, mechanical design/fabrication.
- Software Development: David Martin - Data acquisition control, GUI, Paul Roberts - Calibration, data analysis/algorithms.
- Optical Consultant: Karl Moore
- Lab Assistants: Jeremy Seymour, Casey Ta
- Graduate Students: Paul Roberts, Erdem Karakoylu, Jennie Cochran
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    References
- Franks PJS, Jaffe JS. 2008. Microscale variability in the distributions of large fluorescent particles observed in situ with a planar laser imaging fluorometer. Journal of Marine Systems. 69:254-270.
- Franks PJS, Jaffe JS. 2001. Microscale distributions of phytoplankton: initial results from a two-dimensional imaging fluorometer, OSST. Marine Ecology Progress Series. 220:59–72.
- Palowitch AW, Jaffe JS. 1995. Optical Serial Sectioned Chlorophyll-Alpha Microstructure. Journal of Geophysical Research-Oceans. 100:13267-13278.
- Jaffe JS. 1990. Computer Modeling and the Design of Optimal Underwater Imaging-Systems. IEEE Journal of Oceanic Engineering. 15:101-111.