Resolving POSPac GNSS Import Error: Missing Leap Second Information

📌 Problem

When importing GNSS data into POSPac, users may encounter the following error:

Import Error: The selected GNSS data file cannot be imported because it does not include accurate leap second information. Select "Check for Updates" on the Start Page to download the latest leap second information. Then try again to import the file.

🔍 Root Cause

This issue typically arises when the GNSS ephemeris file (e.g., .25g file) lacks up-to-date leap second data. This is especially common with files generated after July 2025. POSPac requires accurate leap second configuration to correctly interpret satellite timing data.

✅ Probable Resolutions

1. Update Leap Second Configuration Manually:

   • Download the latest LeapSeconds.xml file from Trimble.

     <?xml version="1.0" encoding="utf-8"?>
     <LeapSeconds version="1.0" date="2026-07-01">
       <!-- Time type entered here is UTC -->
       <LeapSecond year="1980" month="1" day="6" leapSec="0"/>
       <LeapSecond year="1981" month="7" day="1" leapSec="1"/>
       <LeapSecond year="1982" month="7" day="1" leapSec="2"/>
       <LeapSecond year="1983" month="7" day="1" leapSec="3"/>
       <LeapSecond year="1985" month="7" day="1" leapSec="4"/>
       <LeapSecond year="1988" month="1" day="1" leapSec="5"/>
       <LeapSecond year="1990" month="1" day="1" leapSec="6"/>
       <LeapSecond year="1991" month="1" day="1" leapSec="7"/>
       <LeapSecond year="1992" month="7" day="1" leapSec="8"/>
       <LeapSecond year="1993" month="7" day="1" leapSec="9"/>
       <LeapSecond year="1994" month="7" day="1" leapSec="10"/>
       <LeapSecond year="1996" month="1" day="1" leapSec="11"/>
       <LeapSecond year="1997" month="7" day="1" leapSec="12"/>
       <LeapSecond year="1999" month="1" day="1" leapSec="13"/>
       <LeapSecond year="2006" month="1" day="1" leapSec="14"/>
       <LeapSecond year="2009" month="1" day="1" leapSec="15"/>
       <LeapSecond year="2012" month="7" day="1" leapSec="16"/>
       <LeapSecond year="2015" month="7" day="1" leapSec="17"/>
       <LeapSecond year="2017" month="1" day="1" leapSec="18"/>
     </LeapSeconds>

   • Replace the existing LeapSeconds.xml file located at:
     C:\ProgramData\Trimble\LeapSecondsConfig
   • Restart POSPac and retry the GNSS file import.
2. Upgrade POSPac Software:
   • When compatible, upgrade from POSPac v9.4, or earlier, to POSPac Complete v2025.10.1, which includes a fix for this issue.
   • If you encounter licensing issues, Contact Support to resolve entitlement errors.
3. POSPac Cloud Users:
   • Should no longer encounter this issue as Trimble has rolled out the fix.
   • Wait 24 hours to process the cycle.

📎 Additional Notes

• As a temporary workaround, users can request processed trajectory files from support.
• Refer to the official Trimble Service Bulletin for more technical details.

Tip: Always ensure POSPac is updated before processing new GNSS data to avoid leap second discrepancies.

📬 Need Help?

If you're still stuck, please Contact Support for assistance.