leap second

What Is A Leap Second?

We all know that a Leap Day synchronises our current calendar year with the solar year; the length of time it takes the Earth to orbit around the sun. But what is a Leap Second and why is it important to Surveyors?

It’s exactly the same concept with a Leap Second. Every four years an additional second is added to the Coordinated Universal Time (UTC) to synchronise our current clocks worldwide with the Earth’s rotation.

Glonass is aligned to UTC while GPS, BeiDou and Galileo are aligned to international atomic time, and because of this difference you may experience some GNSS issues with Glonass tracking after midnight 31 Dec 2016 UTC ( 1pm Jan 1st NZDT) due to Leap Second synchronising.

What To Expect During The Leap Second Switch:
For GPS, Galileo and BeiDou, all Leica receivers will not be affected over the leap second change. GLONASS tracking will lose lock briefly and recover a few seconds later.

What To Expect When Starting Equipment After The Leap Second Switch:
If a Leica receiver is used after the leap second switch, the receiver will have trouble tracking GLONASS signals until a new almanac is downloaded, which can take up to a few minutes. A Reset Almanac will resolve the problem faster and enable users to track GLONASS satellites again.

How To Resolve Leap Second Issues:
If a Leica System is used after the leap second switch, the receiver should have no trouble tracking GLONASS signals. However, if there are problems tracking GLONASS satellites, an ME reset will resolve the problem faster.

How To Perform An ME Reset:

  • A Viva/Captivate receiver should have no trouble tracking GLONASS signals. If there are issues tracking GLONASS satellites, restart the receiver.
  • With an iCON receiver follow this process: Settings > System Configuration > Reset Options > Reset Almanac. This will clear almanacs and track GPS only until a new almanac has been received.
  • For System 1200/900 follow this process: Press 5 Config > 2 Instrument Settings > 2 Satellite Settings > shift F4 INIT.

Users should ensure the GPS/GNSS instruments have all the latest updates to avoid and minimise any discontinuation of service due to the introduction of the Leap Second.

If you’re still having issues resetting your Leica receiver, we’re here to help.

Contact our technical support team on 0800 453 422.