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April 6, 2019 GPS w...
 
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April 6, 2019 GPS week rollover  

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leegreen
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Wonder what GNSS receivers may be affected by this. I don't see any vendors talking about, maybe it is not relevant.

A GPS Week Rollover happens because of the way the navigation signal works. The current week number is encoded into the signal message received from the satellites using a 10-bit field, and this allows for a week range from zero to 1023. The current period began back on 1 August 1999, and on 6 April 2019 the week number rolls over back to zero, where it will start counting back up to 1023.

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leegreen
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Appears Topcon may be creating firmware updates to address the Rollover. They are late to the game.

Here is a list of Topcon receivers with the recommended firmware for the rollover.

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toivo1037
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Posted by: leegreen

Appears Topcon may be creating firmware updates to address the Rollover. They are late to the game.

Here is a list of Topcon receivers with the recommended firmware for the rollover.

"Contact Dealer for Trade-in/Update"  DAMMIT. (but expected)  I wonder if they will still work for static.  I didn't have to update my oldest set the last time this happened, and they still worked for static.  Now I add another 'obsolete' set to the mix.  Maybe everything will still work, otherwise I lose 8 receivers I use for static networks.

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Lee D
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I would expect it to affect most of the old equipment out there. Although I don't remember it being a big deal in '99, but most of the receivers in use in '99 were probably five years old or less.

Coincidentally, I just got the digital xyHt in my inbox and Gavin wrote an editorial on just this very topic. It sounds like anything Trimble made since 2003 is ROW compliant, and he provides a link where they're posting info that they receive from other manufacturers.

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gschrock
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Posted by: Lee D

I would expect it to affect most of the old equipment out there. Although I don't remember it being a big deal in '99, but most of the receivers in use in '99 were probably five years old or less.

Coincidentally, I just got the digital xyHt in my inbox and Gavin wrote an editorial on just this very topic. It sounds like anything Trimble made since 2003 is ROW compliant, and he provides a link where they're posting info that they receive from other manufacturers.

Lee,  We have gotten responses back from most of the manufacturers (we sent a questionnaire to their GNSS dev teams)... we will put an online post with all of those responses live on the 1st of March, and will add other responses (and updates) as we receive them.

Good news is, in  short, is they all say pretty much the same thing:  if gear was made after say 1999, then either it shipped compliant, or a firmware since has made them compliant.

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Lee D
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I'm going to guess that, especially since we've already done this once, they all knew this was coming - obviously - and planned for it; it would be bad business not to.

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gschrock
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Posted by: Lee D

I'm going to guess that, especially since we've already done this once, they all knew this was coming - obviously - and planned for it; it would be bad business not to.

That was pretty much the message.... Full WNRO post live now.

Part of planned GPS modernization is supposed to be a move to a 13-bit message (10-bit can only count up to 1024 weeks, or about 20 years) and that would change the WNRO (week number rollover) cycle to 157 years.

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Larry Scott
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What about legacy compatibility?

will the change in week number bit assignment affect older equipment? 

My array of Z-12 work great, they record wrong date (easy work around), but if the code is changed will it effect the receiver’s decoding the signal? and possibly quit working? 

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Wendell
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Oh sure, I post an article linking to Gavin's article and THEN I see this thread. 😀

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gschrock
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Posted by: Wendell

Oh sure, I post an article linking to Gavin's article and THEN I see this thread. 😀

Thinking about making "I survived the WNRO 2019" shirts.... err, maybe not... 😉

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hpalmer
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Wendell,

if it is any 'constellation', I read your link first

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Jim Frame
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No response from Javad yet?

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gschrock
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Posted by: Jim Frame

No response from Javad yet?

Third hand that there is a thread on the J forum that addresses the issue (sounds like all is good as most gear is newer than 10-15 years) and there is a link to relese notes for specific versions.

Still waiting on a number of other manufacturers, though most are simply users of OEM boards from the ones that have responded so far.

No response yet from Hemisphere GNSS ( they provide much of the gear for late model Carlson gear) but would not expect any issues with their gear (as pertains to survey gear) as many of those boards were developed from scratch within recent years.

 

 

 

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