Fourth Place Digits

[South-Eastern Lights]

Fellow Geocachers,

I often read co-ordinates from other geocachers and geocaching websites that have four digits after the decimal point. My GPS displays only three digits. Are there units that display in four digits? Are they more accurate? Somebody fill me in!

 

The Lights

[Kerry.]

Assuming you are referring to decimal minutes No, not many can display to 4 decimal minutes but many are now able to output 4 decimal minutes to other software packages.

 

Technically more precise due to the extra significant decimal but not really any more accurate as the accuracy is a function of the overlying system, SPS accuracy specifciations and the limitations of the general recreational receiver.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[+Renegade Knight]

The third decimal corresponds to about 6'. On average a GPS is accurate to about 20'. A 4th Decimal can take you to a greater degree of accuracy than 6' but only if you have a GPS that can locate something to that same degree of accuracy. 3 decimals on a modern hand held GPS is as accurage as the GPS can get.

 

Wherever you go there you are.

[+ErSamin]

If I follow the original post, this is what I'm wondering, too. but maybe I am more lost than I think.

 

Example: a cache is posted on the website with the coordinates - N 34 03.827 W 118 00.347. My old Blazer 12 can only receive N 24 03.82 W 118 00.34

 

In my mind, (or in my GPSr) should I really be thinking N 34 03.83 W 118 00.35?

 

How does one with an old unit such as this report coordinated for their hidden cache?

[+The Merman]

Put a zero on the end?

 

I woke this morning and my boat was not rocking...for one horrid moment I thought I lived in a house!

[Shnde]

When I was using a Megellan GPS 2000 with only 2 decimal places, I used the 4/5 rounding so I would also round up over 5. But if the third decimal is only 6', I do not think it would make much difference. I am often 10 to 20 meters, even 30 meter off on the GPS while sitting at the cache site. So the last digit never played much in the whole scheme of things, now accurancy, receivability and quick averaging did and I ended up with a number of no finds at first, very fustrating. Better now with my present GPS and would most likely be the same if I rounded and left the last number 0. Most times the GPS gets you to the area and then you search from there, better to have a 10 to 30 meter search area then a 100 meter search area as the 2000 went to 0.1Km and my newer one goes to 0.01Km. Have not tried one that gets down to the meter. Ran into one fellow with an etrex tho on the weekend, at the cache site he was 7meters off and I was 0.01Km or 10 meters off, not much once you factor in the accurancy and inherent error. He used the hint to find the cache, I just asked for the log book when he was finished. Only the second time I have run into someone else at a cache in 56 finds.

 

Car37