Non-linear statistical photocalibration of photodetectors without calibrated light sources
Abstract
Calibration of CCD arrays is commonly conducted using dark frames. Non-absolute calibration techniques only measure the relative response of the detectors. For absolute calibration to be achieved, a second calibration is sometimes utilized by looking at sources with known radiances. A process like this can be used to calibrate photodetectors if a calibration source is available and sensor time can be spared to perform the operation. A previous attempt at creating a procedure for calibrating a photodetector using the underlying Poisson nature of the photodetection statistics relied on a linear model. This effort produced the statistically applied non-uniformity calibration algorithm, which demonstrated an ability to relate the measured signal with the true radiance of the source. Reliance on a completely linear model does not allow for non-linear behaviors to be described, thus potentially producing poor photocalibration over large dynamic ranges. In this paper, a photocalibration procedure is defined that requires only first and second moments of the measurements and allows the response to be modeled using a non-linear function over the dynamic range of the detector. The technique is applied to image data containing a light source measured with different integration times showing that the non-linear technique achieves significant improvement over the linear model over a large dynamic range.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 18, 2020
- Source ID
- 10.1364/ao.385753
Entities
People
- Stephen C. Cain
Organizations
- Air Force Office of Scientific Research