  Nowadays, in Positron Emission Tomography (PET) systems, a Time of Flight
information is used to improve the image reconstruction process. In Time of
Flight PET (TOF-PET), fast detectors are able to measure the difference in the
arrival time of the two gamma rays, with the precision enabling to shorten
significantly a range along the line-of-response (LOR) where the annihilation
occurred. In the new concept, called J-PET scanner, gamma rays are detected in
plastic scintillators. In a single strip of J-PET system, time values are
obtained by probing signals in the amplitude domain. Owing to Compress Sensing
theory, information about the shape and amplitude of the signals is recovered.
In this paper we demonstrate that based on the acquired signals parameters, a
better signal normalization may be provided in order to improve the TOF
resolution. The procedure was tested using large sample of data registered by a
dedicated detection setup enabling sampling of signals with 50 ps intervals.
Experimental setup provided irradiation of a chosen position in the plastic
scintillator strip with annihilation gamma quanta.
