The Use of GPS Disciplined Oscillators as Primary Frequency Standards for Calibration Laboratories
Michael A. Lombardi
Many calibration and testing facilities now employ a Global Positioning System disciplined oscillator (GPSDO) as their primary frequency standard. GPSDOs have the advantage of being much less expensive than cesium oscillators, and in theory, serve as "self-calibrating" standards that should not require adjustment or calibration. This makes them an attractive choice for many laboratories. However, there are some performance characteristics that make a GPSDO less suitable for some applications than a cesium. This paper explores the use of GPSDOs in calibration laboratories. It discusses how GPSDOs work, how measurement traceability can be established with a GPSDO, and how their performance can vary significantly from model to model. It also discusses possible GPSDO failure modes, and why a calibration laboratory needs to be able to verify whether or not a GPSDO is working properly.
The Use of GPS Disciplined Oscillators as Primary Frequency Standards for Calibration Laboratories, Proc. NCSLI Conf., Orlando, FL, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=842470
(Accessed June 6, 2023)