Data Logger - sudden change in date

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smbohn
Posts: 9
Joined: Fri Aug 04, 2017 9:35 pm

Data Logger - sudden change in date

Post by smbohn »

On my flight yesterday, at about 1100 feet on climbout after takeoff, the data logger suddenly reported a different date. It switched from 7/12/25 to 11/26/05. See line 594 in the attached file.

That's never happened before. Any ideas on how this might have happened?

Thanks... Steve
Attachments
GRT FDL 0157.xlsx
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GRT_Jeff
Posts: 854
Joined: Tue Dec 11, 2012 12:11 am

Re: Data Logger - sudden change in date

Post by GRT_Jeff »

It looks like a GPS week rollover issue. There are old GPS receivers out there (or external GPS units with very old databases) that no longer know what time period they are in. GPS satellites count up to 1024 weeks, but they don't specify what period of weeks those are. The GPS has to know that. We added software to all display software updates in May 2019 to detect this for most modules and bump the date to the current 1024 week range. If you have an HX with display software older than 2019 then try the latest display update from 2022 on our web site. In the Excel file you can add 1024*7 days to the date to correct it.
smbohn
Posts: 9
Joined: Fri Aug 04, 2017 9:35 pm

Re: Data Logger - sudden change in date

Post by smbohn »

Fascinating. Thanks Jeff!
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