What is the extra number in coordinates on our Oregon 700?

[Boseducoaching]

We just bought a Garmin Oregon 700. When we insert a coordinate there is one extra number at the end. Normally it looks like:

N 52° 29.106

E 004° 39.332.

However, we now have:

N 52° 29.106X

E 004° 39.332X

We assumed that it is to be extra precise. We just fill it as zero and it brought us the cache.

Nevertheless, can someone confirm this for us? Is it to be extra precise or is there another reason that it is there?

 

Thanks in advance.

[+Max and 99]

16 minutes ago, Boseducoaching said:

We just bought a Garmin Oregon 700. When we insert a coordinate there is one extra number at the end. Normally it looks like:

N 52° 29.106

E 004° 39.332.

However, we now have:

N 52° 29.106X

E 004° 39.332X

We assumed that it is to be extra precise. We just fill it as zero and it brought us the cache.

Nevertheless, can someone confirm this for us? Is it to be extra precise or is there another reason that it is there?

 

Thanks in advance.

All my waymarks do this after I submit them. This has been discussed/explained in a forum thread but it's above my head. ?

[+on4bam]

There's a thread about this already. It doesn't make much difference for now, at least I keep the last digit at 0. Galileo, the European satellite system, has a greater accuracy than GPS and may then offer an advantage  having the extra digit.

For now, as geocaching only uses 3 digits you can ignore the extra one.

 

[+on4bam]

I found the thread, it was about the Garmin 66st.

 

 

And here.

 

Edited July 24, 2020 by on4bam

[+Hügh]

34 minutes ago, on4bam said:

at least I keep the last digit at 0

 

Wouldn't making the last digit(s) 5's be "more" accurate (probably not by much... perhaps it's not even "worth it"?)

 

EDIT: seems like it's discussed in the other thread. Will read when I have time.

Edited July 24, 2020 by Hügh

[+Max and 99]

2 minutes ago, Hügh said:

 

Wouldn't making the last digit(s) 5's be "more" accurate (probably not by much... perhaps it's not even "worth it"?)

I would think so! 

[+on4bam]

7 minutes ago, Max and 99 said:

I would think so! 

Only when using Galileo. It makes no difference for GPS/Glonass

 

[+Max and 99]

6 minutes ago, on4bam said:

Only when using Galileo. It makes no difference for GPS/Glonass

 

You lost me.

[+SamLowrey]

2 hours ago, Max and 99 said:

You lost me.

Apparently there is a European GPS system that is supposedly more accurate?

Edited July 24, 2020 by SamLowrey

[+ecanderson]

The best of the systems will incorporate correction information (inherently) that is now served by EGNOS and WAAS, and US GPS will add (has already added, but not yet for use) a new band that will provide an additional data point to provide better coordinates.  NONE are expected to be of any real use down to a fourth number after the decimal.  What they will do is make the 3rd decimal a little more reliable.  At this point, and for any hardware currently headed for orbit, there is no reason to support a 4th digit after the decimal.

[+Max and 99]

I thought the point was that if you have to choose a 4th digit when entering coordinates, pick a five cuz it's in the middle.  This I get. Everything else is over my head. ?

[+ecanderson]

Adding 0.0005 doesn't make any more sense than subtracting 0.0005.

For example, if the coordinates in question are N40 08.683, arbitrarily calling it N40 08.6835 isn't any better or worse than calling it N40 08.6825.

Since you don't know which way the actual error runs between your fix and the location, you're just as well off using 0 and calling it N40 08.6830, and the 0 is likely already filled in.

[+Hügh]

3 hours ago, ecanderson said:

Adding 0.0005 doesn't make any more sense than subtracting 0.0005.

For example, if the coordinates in question are N40 08.683, arbitrarily calling it N40 08.6835 isn't any better or worse than calling it N40 08.6825.

Since you don't know which way the actual error runs between your fix and the location, you're just as well off using 0 and calling it N40 08.6830, and the 0 is likely already filled in.

Ah, makes sense. Thank you!

[Boseducoaching]

Thanks for the answers and sorry for not finding the earlier topics.

 

I got my answer, so the topic may be closed as far as I am concerned.

[+SamLowrey]

17 hours ago, ecanderson said:

Adding 0.0005 doesn't make any more sense than subtracting 0.0005.

For example, if the coordinates in question are N40 08.683, arbitrarily calling it N40 08.6835 isn't any better or worse than calling it N40 08.6825.

Since you don't know which way the actual error runs between your fix and the location, you're just as well off using 0 and calling it N40 08.6830, and the 0 is likely already filled in.

Heh, you changed my mind back.   At first 0 sounded reasonable, then 5, now 0 again.  This could be a topic for Numberphile or Mathloger.  Mathlogger always makes me think of that character in Big Lebowski "Knox Harrington."

[+TorqueMaster]

On 7/24/2020 at 5:19 PM, ecanderson said:

Adding 0.0005 doesn't make any more sense than subtracting 0.0005.

For example, if the coordinates in question are N40 08.683, arbitrarily calling it N40 08.6835 isn't any better or worse than calling it N40 08.6825.

Since you don't know which way the actual error runs between your fix and the location, you're just as well off using 0 and calling it N40 08.6830, and the 0 is likely already filled in.

 

Agreed.  Make the last digit a zero. 

 

*IF* the device had 4 decimal resolution, and rounded the display to 3 digits,  0 would fall in the "middle" of the possible coordinates.   Say N40 08.6825 through N40 08.6834 gets rounded to N40 08.683.  If it truncates, make it a 5.  No way to be sure, so just use zero.  This is all pretty moot since those 4th digits are only  going to change GZ by 8ish feet at most. We're geocaching, not surveying.

 

 

[+ecanderson]

Every 0.001 is worth about 4.7' E/W (at my latitude) and 6.1' N/S everywhere (e.g., 0.002 difference in N/S coordinate is 12' difference).

 

[+fizzymagic]

On 7/24/2020 at 10:08 AM, Hügh said:

 

Wouldn't making the last digit(s) 5's be "more" accurate (probably not by much... perhaps it's not even "worth it"?)

 

EDIT: seems like it's discussed in the other thread. Will read when I have time.

 

Short answer:  no.

[+ras_oscar]

ok, my take away from reading this thread, there is a new system available in some areas that uses the 4th digit. Garmin has added the 4th digit to their newer units to be compatible with the future. When the new system becomes available area, all existing gpsrs that only support 3 will by default be using a zero as the 4th digit.

[+ecanderson]

15 hours ago, ras_oscar said:

ok, my take away from reading this thread, there is a new system available in some areas that uses the 4th digit. Garmin has added the 4th digit to their newer units to be compatible with the future. When the new system becomes available area, all existing gpsrs that only support 3 will by default be using a zero as the 4th digit.

Nope.  The 'systems' don't create the numbers.  The GPSr does that based upon signal timing and known satellite positions, and toss in any correction data being supplied by ancillary SBAS systems (e.g, WAAS or EGNOS) or new generation birds that manage that without 'outside assistance'. 

 

No commercial/consumer satellite/receiver system is being suggested at this time (or at any anticipated date) that will provide the positional accuracy necessary to make the 4th digit after the decimal useful.  At this time, the THIRD digit isn't typically dependable (+/- 0.003 is a reasonable expectation in many circumstances), and the FOURTH digit is noise.  For now and into the foreseeable future, he only way to get 4-digits-after-the-decimal accuracy (better than what you currently see in the field) is to set up a ground based reference system (see articles on GBAS/DGPS).

 

Think about it.  If the THIRD digit were always good, you'd be assured of a 4x6 foot box to work in (give or take, depending upon latitude). 

 

Edited August 10, 2020 by ecanderson