The precision and accuracy of the Satellite Laser Ranging (SLR) is one of the biggest issues for the entire network to perform as a calibrator of the other space-born geodetic systems and to establish millimeter level accurate terrestrial reference frame. The principal idea behind the Portable Calibration Standard (PCS) is the high degree of redundancy in measuring hardware, data analysis software and operational procedures. The most rigorous calibration would involve a complete reference SLR system, which would collocate with the system under test, a more economical approach allows the laser, telescope and optical detectors of the system under test to be shared. In this configuration, the output timing signals from the optical detectors are processed in an independent device - Portable Calibration Standard. It consists of the Pico Event Timer, GPS time and frequency receiver, meteorological sensor and a personal computer with the software package. The main parameters of the PCS based on a Pico Event Timer are: single shot precision 3 psec rms, timing linearity 2.5 psec, stability +/- 0.5 psec/hour, drift below 0.1 psec/K, the accuracy traceable down to US National Standards.