Physical Sciences and Mathematics Commons^™

Selecting Island Pixels With A Likelihood Ratio, Jordan Tweddale

Physics

A new method, called the Log Likelihood Ratio (LLR), was employed in place of a Signal-to-Noise Ratio (SNR) to pick out signal pixels on the VERITAS (Very Energetic Radiation Imaging Telescope Array System ) telescopes. The LLR test was performed on both photoelectrons and timing for VERITAS to select island pixels in Stage 2 cleaning, which is where the camera image is processed to determine which pixels on the camera are signal, and which are background. The two LLRs were combined to form a final LLR, which has a numerical cut, LLR = 11.5, between signal and background pixels. The …