Accurate time keeping is essential to accurate orbital predictions. Nova's Internet Time Setting feature allows the user's computer clock to remain within about 50 milliseconds of the correct time. It uses the internet to connect to open-access NTP Stratum-1 servers that keep extremely precise time, such as those maintained by NIST and the U.S. Navy.
The Internet Time Setting feature is activated from Nova's Main Menu/Utilities and also from Setup/Time.
Stratum-1 time servers lists a variety of servers available to the general public. You should select a server that is located close to you so as to minimize variability in routing and trip delay.
Local computer clock shows the time read from your computer clock at the moment of synchronization. This field will be empty before synchronization occurs.
Server clock shows the time that was reported from the remote time server.
Auto. synchronize tells Nova whether to automatically synchronize the local computer clock on a regular basis. Use this feature if accurate timekeeping is not otherwise possible with your computer's clock and if you have a permanent (i.e. cable modem, DSL) internet connection. We do NOT recommend using Auto synchronize if you have a dial-up modem because Nova will attempt to synchronize and interrupt any ongoing telephone connection. Set the interval (hours, days) in the boxes to the right.
Data pertaining to time synchronization are reported in the four fields immediately above the buttons.
Error is the difference between the computer's clock and the server's clock at the moment of synchronization. In the example above, the error was 0.233 seconds.
Round trip time is the time between sending a request for time and the arrival of the answer. You should select a server that provides a short round-trip time. Long times may indicate multiple relay points along the path. The Internet time setting function assumes a symmetrical path delay, which may not be true with long paths.
The core routines for the Internet Time Setting function were written by Dirk Claessens and Francois Piette.