The development of an automatic track measurement system for the magnetic passive isotope experiment

Technical Report · Sun Aug 01 04:00:00 EDT 1993

OSTI ID:451219

Liu, Zhen

The purpose of this project is to develop an automatic track measurement system for the MAGPIE (MAGnetic Passive Isotope Experiment). MAGPIE track measurement is currently being conducted at the University of Utah, using a computer image processing and pattern recognition system coupled to a laser-interferometer-controlled microscope stage. After etching, MAGPIE flight CR-39 plastic sheets are placed on the microscope stage. This stage is controlled by an intelligent stage controller. The stage controller receives the motion commands from a Sun workstation to bring an area of interest under the microscope. A CCD camera picks up the image of the plastic surface (which contains the tracks of the cosmic ray particles) through the microscope and sends the video signal to a special image processing hardware. In the image processing system, the input video signal is digitized, the resulting digital image is thresholded by its intensity, and the gradient image is generated. The gradient image is thresholded again and the resulting gradient pixels (referred to as features) are extracted and sent to the Sun workstation. A superposition of the features on the original image is displayed on a monitor for human inspection. In the Sun workstation, these features are grouped into clusters, which are then examined for possible track candidates. The suspected noise clusters are discarded and the candidate clusters are fitted with ellipses. All the {open_quotes}good{close_quote} ellipse fits are considered real particle tracks, their parameters are converted from the video coordinate to the stage coordinate and stored in a data file. This whole scanning process can be done without human intervention, except for the initial sheet placements and program execution. The working principles, implementation details, and operating procedures of each subsystem are discussed in great detail in this paper. Finally, some possible further improvements on this system are discussed.

• Research Organization: Utah Univ., Salt Lake City, UT (United States). Dept. of Physics
• Sponsoring Organization: USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: FC08-89NV10865
• OSTI ID: 451219
• Report Number(s): DOE/NV/10865--T6
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
99 GENERAL AND MISCELLANEOUS
AUTOMATION
COSMIC RADIATION
DIELECTRIC TRACK DETECTORS
ETCHING
IMAGE PROCESSING
IRON
IRON 57
ISOTOPE RATIO
MAGNETIC SPECTROMETERS
MEASURING METHODS
MICROSCOPY
PARTICLE TRACKS
PATTERN RECOGNITION
PLASTICS
VELOCITY