GPS Firmware just might need updating....

Discussion in 'Survival Communications' started by BTPost, Feb 27, 2019.


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  1. BTPost

    BTPost Stumpy Old Fart Snow Monkey Moderator

    I am NOT saying that this is FACT, but it is worth looking into, if GPS is important to you....

    FYI: 2-26-2019 mFrom:The Register (British IT News Site)*
    <Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019>*
    *Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh
    heck – April 6, 2019*
    Nav gadgets will be Gah, Properly Screwed if you don't or can't update firmware*
    By Shaun Nichols in San Francisco
    <Shaun Nichols • The Register> 12 Feb 2019 at 21:37

    Older satnavs and such devices won't be able to use America's Global
    Positioning System properly after April 6 unless they've been suitably updated
    or designed to handle a looming epoch rollover.

    GPS signals from satellites include a timestamp, needed in part to calculate
    one's location, that stores the week number using ten binary bits. That means
    the week number can have 2^10 or 1,024 integer values, counting from zero to
    1,023 in this case. Every 1,024 weeks, or roughly every 20 years, the counter
    rolls over from 1,023 to zero.

    The first Saturday in April will mark the end of the 1,024th week, after which
    the counter will spill over from 1,023 to zero. The last time the week number
    overflowed like this was in 1999, nearly two decades on from the first epoch in
    January 1980.

    You can see where this is going. If devices in use today are not designed or
    patched to handle this latest rollover, they will revert to an earlier year
    after that 1,024th week in April, causing attempts to calculate position to
    potentially fail. System and navigation data could even be corrupted, we're warned.

    "GPS devices with a poorly implemented GPS Time-to-UTC conversion algorithm may
    provide incorrect UTC following a week number rollover," US Homeland Security
    explained in its write-up
    <https://ics-cert.us-cert.gov/sites/default/files/documents/Memorandum_on_GPS_2019.pdf>
    (PDF) of the issue this week.

    "Additionally, some GPS devices that calculate the week number value from a
    device-specific date rather than the start of the current GPS Time Epoch may
    provide incorrect UTC at some other device-specific date."

    As the /Reg/ reader who tipped us off to the shortcoming noted, this could be a
    significant headache for data centers that use GPS timing for synchronization.

    "Decent vendors should have patches. But who has been thinking about this?" our
    tipster told us. "This could be a low-key Y2K style bug all over again, but
    with companies doing less preparation."

    Fortunately, devices on sale right now should be prepared for this rollover and
    handle it gracefully. Uncle Sam's GPS nerve-center GPS.gov says
    <https://www.gps.gov/cgsic/meetings/2017/powers.pdf> (PDF) receivers that
    follow the ICD-200/IS-GPS-200 specification should be able to deal with the
    week number overflow. This basically means newer receivers built after, say,
    2010 should be fine, provided they follow the specs
    <GPS Technical References> and notice the
    rollover.

    To put it another way, if your gadget goes haywire in April, it's probably
    because of this. If it works as normal: brilliant, it's not affected. Consider
    yourself forewarned.

    GPS.gov also notes that the new CNAV and MNAV message formats will use a 13-bit
    week number to solve the epoch migraine right up until the planet becomes
    uninhabitable via climate change or we all blow ourselves up.

    For devices unprepared for the counter overflow, a firmware upgrade will be
    necessary to keep the things working properly. GPS.gov recommends those unsure
    about their readiness for the turnover, particularly enterprises, should
    consult the manufacturer of their equipment to make sure they have the proper
    updates in place. ®
     
  2. Altoidfishfins

    Altoidfishfins Monkey+++ Site Supporter+

    Thanks for the headsup BT.
    I have a Garmin GPSIII that was manufactured around 1997 - 98.
    It seems to have a much better receiver than the newer ones, but this could shut it down.
    Don't think Garmin supports it any more, have to check to see if they have an update on their web site.
    At least now if it goes bonkers I'll have some idea of what happened.
     
    techsar and Dunerunner like this.
  3. BTPost

    BTPost Stumpy Old Fart Snow Monkey Moderator

    I have both a III, and a III Plus, that I use for monitoring the Base GPS Signals, when I am planning to do a Differential GPS Survey, or I am looking for Survey Points... Both were Surveyed in, to within a meter or two, and I record their Data Stream over my Network, and then thru Post Processing can get my mobile GPS locations down to inside a 3 Meter Circle... I will be watching them in April and comparing them to my iDevices GPS Locations...
     
    Gator 45/70 and techsar like this.
  4. Dunerunner

    Dunerunner Brewery Monkey Moderator

    My old Garmin portable for my truck and the Kenwood in dash in my 2005 auto are unsupported and will probably become obsolete, prompting the necessity for me to purchase another $2K in equipment and installation.
     
    Gator 45/70 likes this.
  5. lol. My GPS is a compass, maps, and both a sextant and astrolabe I built myself from PDF's in my library. I'm a low tech kinda guy....lol
     
    Gator 45/70 and techsar like this.
  6. techsar

    techsar Monkey+++

    How many pdfs did it take to build the sextant?
    .
    .
    .
    Sorry, couldn't resist.... ;)
     
  7. Only 1, I have a very good step by step manual. Check it out.
     

    Attached Files:

    Ganado, Idahoser and ghrit like this.
  8. Cruisin Sloth

    Cruisin Sloth Special & Slow

    Folks with a TOM-TOM
    [​IMG]
    Check your sextant below
    Update your navigation device | TomTom


    The GPS Week Number Rollover (WNRO) occurs every 19 years, with the next rollover taking place on April 6, 2019. Similar to odometers in older cars rolling over from 99,999 miles to 0 miles the GPS WNRO is the resetting of the GPS calendar back to 0.

    When the calendar resets, it can cause a miscommunication between GPS satellites and GPS receiver chips. As a result, some chips in navigation devices will lose the ability to process certain functions.

    What does this mean for you? It's time to check your navigation device. Depending on your device, you may need to update or upgrade.
    Sloth
     
    oldman11 likes this.
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