GPS-Based Time Stamp System

摘要

A system and method for providing time stamps protected from GPS timing signal attacks. A GPS receiver receives a GPS time data, and a local clock provides local time data. A controller initiates the local clock with the GPS time data. It continuously monitors the GPS time data by calculating any difference error between current GPS time data and local time data, and determining whether the error exceeds a threshold value. If the error does not exceed the threshold value, the GPS time data is used to discipline the local clock data and the disciplined output is used for the time stamp. If the error exceeds the threshold value, the local time data is used for the time stamp.

主权项

1. A time stamp validation system, comprising:
a GPS receiver operable to receive a GPS time signal representing GPS time data; a local clock operable to provide local time data; a controller operable to perform at least the following tasks: initiate the local clock with the GPS time data; calculate any difference between current GPS time data and local time data, thereby obtaining error data; to determine whether the error data exceeds a threshold value; if the error data does not exceed the threshold value, discipline the local clock data with the GPS time data and to use the disciplined output for the time stamp; and if the error data exceeds the threshold value, use the local time data to provide the time stamp.