What is the most accurate GPS device?

9-29-05 | delphinium

[Delphinium]

I know this is a personal matter but I am waiting for Garmin tech support to answer. I am wanting to buy a GPS device that is accurate atleast to 2 meters.

I know there are many high tech and high intellectual folks of Freerepublic, so I decided to ask.

[Red Badger]

If you marry my ex-wife, she'll tell you where you are going to be before you even think about going there.......

[Sam Cree]

"I use a map and a compass. No batteries needed."

A watch is mighty handy too.

[caver]

I have an older copy of Corpscon.

Does it convert from legal descriptions(quarter-quarter) to lat-long or UTM? If it does, I was not aware of it.

[M1911A1]

Those ARKON units look slick, and if I was going to use a unit primarily in a vehicle I'd be sorely tempted.

I AM sorely tempted. Darn that gadgetitis, anyway.

[Hegemony Cricket]

waypoint

[jaydubya]

The surveyors used a GPS device to locate my property corners. I'm curious, as the earth's surface moves(ever so slightly) in relation to the satillites in orbit, wouldn't the corners of your property change with these movements?

[antaresequity]

I use a Garmin iQue M5 GPS(WAAS) PDA running windows mobile. The M5 is also BlueTooth enabled. (I have also used a Socket GPS BlueTooth with my Palm TREO, though you have to hack/flash the BIOS of the receiver to enable WAAS/SBAS.)

The best accuracy I have gotten is about 5-7 Meters with WAAS. I use the device for golf, so I am constantly returning to the exact same spots (Tee Boxes). I have constantly found that the GPS is not accurate enough to determine distance for the purpose of playing golf.

Civilian GPS doesn't tell you where you are...it only tells that you are located inside of a circle with a diameter that averages 60-70 feet.

For getting out of the woods its fine. But for mapping accuracy its totally inaccurate.

However there is an excellent program available for about 39 bucks that allows you to upload an aerial photo. Once the photo is in the software, you record index or calibration points. Ideally you record the 4 extents, and a few points in the middle.

The next time you use the GPS/Photo map, the accuracy is very very good because the software uses averaging algorithms to extrapolate your position on the map given the current fix, cast against the previous index points and taking into to consideration the derived scale of the image.

The mapping software is called GPS Tuner and can be found here

Info on the Garmin iQue M5 can be found here.

[FLCowboy,]

What other uses do FReepers have for GPS?

I use my Magellan Meridian Gold when traveling. It has a built-in data base of cities, so we can pull up the city we are approaching, and learn how far away we are from the city.

[antaresequity]

A watch is mighty handy too

Given a line of sight to the sun, an analog WATCH IS A COMPASS.

Not considering Daylight time, If you take an analog watch, hold it like a sun dial (flat) and point the hour hand at the sun, then HALF WAY BETWEEN THE HOUR HAND NOON IS DUE SOUTH (without magnetic deviation of course).

[JeffreyH]

Unless you are in California - there isn't much movement of the earth surface. We do get what you call frost heave and/or soil creep - so an iron pin rebar placed as the corner may shift by less than an inch or so... We even seen a few hit by mowers or pulled by neighbors and reset...

The coordinates were also based on other evidence found in the field (fences, other pins, neighbors lots, etc.) and then based upon your deed of record.

[antaresequity]

What other uses do FReepers have for GPS?

Golf

[yarddog]

Just out of curiosity, after reading this post, I got out my little GPS unit and turned it on, inside the house.

I just noticed it is reading four satellites and claims accuracy at 18 feet.

This is a tiny inexpensive Garmin etrex.

[Plutarch]

Anyone have any experience with wristwatch GPS, such as the Suunto X9i ?

[jaydubya]

Thanks. So, I guess that property I bought on the polar ice cap may not be at the same location as when I last visited. :)

[JeffreyH]

Kinda like the Bob and Tom show where the caller called in about losing his cabin he bought for ice fishing, eh?

Not sure how much movement on the ice cap is - I suppose depends on the temperature... :) Sure would be difficult finding North at the north pole... (which moves year by year as well).

[jaydubya]

I have a good friend whose a surveyor. It sounds like a pretty interesting occupation. I didn't realize all the legalities involvled in it until I had to survey my own property.

[JeffreyH]

Very few people do understand it... one of the least understood (and underpaid) professions. Sometimes the client sees us in the field for a few hours measuring and think thats it. Before going out - we do tons of courthouse research (deeds, plans, right of ways, easements, etc.) - then measure it in the field, then the tough part - reconciling what was found and how it matches the records. I tell people we get a mix of law (big time), measurement, archeaology (digging up called for monuments from the 1900's), botany (finding a 24" black locust that was the corner in 1910), mathematicians (of course), and lastly artists...

I love to solve the puzzles given to me and render a professional opinion, and show it on a clear but detailed plat map.

[Skeeve14]

The GPS system that is used was established by our military. What we use today is +-10m without a 'fill' used in our Mil. PLGR.

That is why China wants to establish their own GPS system so if we ever fought they couldn't be cut off.

[Conspiracy Guy]

Yep. If it is a sunny day I don't need anything.

[Proud Conservative2]

"What other uses do FReepers have for GPS?"

To keep track of an old man out riding in thousands of acres of wilderness alone on ATV. Cell phone can't get out and I want to be able to locate him if need be.