Robust Spatial Calibration of a Planar Positron Camera
Abstract
The planar positron camera is a three-dimensional imaging device with two parallel and planar large crystal detectors. The spatial calibration problem is to define the relation between the raw digitized detector output to a physical coordinate system in the imaged space. In a calibration procedure, a positron point source is placed in a series of known emission locations during data acquisition. Data is then fit to a mathematical model to estimate spatial offsets and gains in the detector. Fitting procedures require some assumptions about error distribution, and the assumption of normally distributed error used in least-squares estimation does not appear suitable for these detectors. In simulated data sets, alternative non-normal distributions (robust estimators) allowed successful recovery of camera spatial parameters even with a few hundred total detected positron emissions. With experimental data, the robust procedures avoided the unreasonable camera performance parameters estimated by least squares. Keywords: Positron; Instrumentation; Image; Mathematical model; Error distribution; Crystal detectors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1988
- Accession Number
- ADA210773
Entities
People
- Paul K. Weathersby
- Paul Meyer
- Shalini S. Survanshi
Organizations
- Naval Medical Research Center