[time-nuts] GPS Week 1536 causing problems?

[Magnus Danielson]

Fellow time-nuts,

Magnus Danielson wrote:
> Fellow time-nuts,
> 
> If you recall, when we hit GPS week 1524 (1024 + 500) we had issues with 
> a few receivers that didn't handle their biased GPS week wrapping 
> correctly. Then the arbitrary constant was 500. Now on Sunday the 
> aribtrary constant of 512 occurs as we enter GPS week 1536 (1024 + 512), 
> as calculated here:
> http://csrc.ucsd.edu/scripts/convertDate.cgi?time=1536+0
> 
> If you see any node having problem, it would be nice to know.
> 
> Hopefully no node fails.

Unfortunatly I have heard a few reports of failures, one which I can't 
disclose the details of right now, but replacing GPS equipment solve the 
issue.

The other was offset by a week, when Vaisala weather equipment was hit.
Vaisala has provided the information in a nice webpage:
http://www.vaisala.com/weather/products/gpswindfindingstatus.html

One of their customers, Esrange (located in northen Sweden) has to stop 
scheduled rocket launches as they where not getting the wind data they 
needed.

Vaisala seems to take this very serious as I am pleased to see on their 
webpage. It took less of a minute of Google time to find that page.

The end result is that there is now a number of software/firmware issues 
which can hit a GPS receiver. Every once in a while they do hit systems.
When they do, they can have rather large impact on system performance 
and limit operations (we have seen national total failure). This is the 
awareness I want to spread.

Cheers,
Magnus