First "new Hide" Question ??

[gridlox]

Started working today for the actual planting of my "first" hide.

 

I'm using a "Magellan Sport Trak Map" GPSr.

 

I went to the location that I'm wanting to hide in and placed the GPSr on the ground and left it there and let the unit do the "averaging" for about 30 minutes while I drowned a few worms close by. (well they were already dead - plastic )

 

I picked up the unit and logged the mark into the database and then loaded it as my "GoTo".

 

It immediately showed me I was 27ft away!!

I didn't move a bit from where it was laying, other than picking it straight up.

(It wasn't actually "laying". I had it propped straight up on a small rock.)

 

As I walked away North it showed me getting closer.

5 more feet and I would have stepped of the bank into chest deep icey cold water!!

 

Is this normal?

Or is it possible I have done something wrong?

 

(Going back in the morning to see how close I come this time)

 

Thinking that the GPSr readings might have been off a bit, on my way back home I went by a benchmark that I found earlier and the GPSr was dead on.

Just as it was when I found it the first time.

 

Benchmark = Extremely clear view of the sky on top of a hill.

 

Hide Spot = In a relatively clear park, with a few trees but right now they are all bare. Next to a river, but readings were took from the top of the bank, not down on the bank. The far river bank is probably 50-60 yards away, so I would think bounce signal shouldn't be the cause of the off reading.??

1.5ft diameter Oak tree was about 2 foot away.

 

Do you think I need to spend more time letting the GPSr average?

Or maybe a few more times drowning worms, is in order?

 

Thanks for any help!!

 

D-man

Edited January 21, 2005 by gridlox

[Tahosa and Sons]

Its close enough, place the cache and let them find it.

[+blindleader]

On the ground is the worst place to get a reading. The higher the better. About five hundred feet above all nearby terrain would be nice but five feet is infinitely better than zero. And don't bother to stand there and average for half an hour. That's just a waste of thirty minutes of your life. Better to take a few fixes when you know the satellites are most favorable. You can search the forums for the carcass of that particular horse. If you dont' want to go through the trouble of planning for good satellites, a check of the EPE when you're taking the fix gives you a fair idea of how good it is.

Edited January 21, 2005 by blindleader

[gridlox]

On the ground is the worst place to get a reading.

 

Didn't know that. Thanks!

 

Got a buddy that has a crane service. Think anybody would notice if I rolled in and used one to get a bit higher?

 

Yeah! I thought so, too!

 

And don't bother to stand there and average for half an hour.

 

But I like drowning worms!!

 

Seriously, what is a good average time to let the GPSr average?

 

D-man

[+JohnnyVegas]

Your Magellan GPS is going to be averaging anytime it is turned on. Just leave it on while you are on the way to the cache location is all you need to do, when you arrive at the cache location just save that waypoint and you are done. Anything around 20 feet is fine. If you are really concerned about the accuracy just add a hint regarding the cache location. Most cachers are going to start looking when they are within 50 feet for anything that might make a good hide location.

Just have fun and don't make it to complicated.

[+briansnat]

Is this normal?

Or is it possible I have done something wrong?

 

Yes it is. Your GPS is only accurate to 15-25 feet under most conditions.

[+1100f]

It may also be that if the visibilty of the sats are in a line, due to say a "canyon" type effect, this can throw the gps out sometimes, as it is generally better to have a wide sky view.

[+Birdsong-n-Bud]

Only the military will get their GPSr's to give them an accuracy reading to within a foot. We mere civilians have to be happy with the 12-27' foot accuracy. It beats the 100' accuracy we had years ago!

 

There was a geomeet activity once. The spot of a waypoint was marked with a post in the ground. Each member of the meet was asked to take their post and mark it where their GPSr said 0'. You would not believe the huge circle of posts that developed after each person did it.

 

You'll also find that when looking for something, one minute you'll be 1' from it, and the next minute, dayum....you are 22' from it, lol. Plays tricks with your mind! But that's what makes it a treasure hunt. Otherwise it'd just be a treasure-find!

 

Don't be afraid to take an average of the waypoint 3 times, and make sure you have reception from at least 3 satellites for the clearest reading. Also, I always use fresh batteries when marking a cache waypoint. I seem to notice that when my batteries get low, the accuracy gets wishy-washy.

 

Have fun!

[+Kit Fox]

I went to the location that I'm wanting to hide in and placed the GPSr on the ground and left it there and let the unit do the "averaging" for about 30 minutes while I drowned a few worms close by.

 

Meridian Gold user here, when you set the GPS down flat on the ground, you partially blocked the antenna. I have better luck averaging by getting my GPS as close to vertical as possible. I have used pieces of wood, or rocks to prop my gps up. So I coul average better. I have even wedged it pnto the top of a bush to take coords for a cache.

 

When I average waypoints, for new caches, I spend no more than five to six minutes averaging. To this day only on person has said anything in a log about coords being off. His accuracy was within the margin of error, so I didn't bother re-averaging.

Edited January 22, 2005 by Kit Fox

[+Night Stalker]

The GPS SporTrak Line gets a better signal if it is vertical then horizontal. When I set a cache I leave it in one spot in a vertical position for around 5 minutes. As long as it is not moving it will average. I also log the mark without moving the GPS. I have had pretty good luck doing it this way.

 

[+AtoZ]

27 feet is with in standard error of 10meters or 33 feet. When I set a cache I take a reading let it average for 30 readings and then stop it. This is a stastical number of readings. Then I do it tow more times. But I have gone back and been off by 20+ feet on a differant day differant conditions. The satelithts move and depending up on the configuration you get diffeant readings. The GPS is NOT accurate to with in a few feet, but to be 10 feet off is acceptable for most non commercial usage.

cheers

[+Kealia]

As far as how long - it's up to you.

 

THere are some here who will tell you to average 30 minutes like you did, or take X amount of averages, etc.

 

I use a Magellan SporTrak Pro, live amongst the Redwoods in the mountains and usually only average for 1 minute or less. STill have no complaints about the coords being off - although MANY logs saying "...lost signal under the trees...."

[+BilboB]

Did you recently replace your batteries? I have a Vista and I have to calibrate the compass and altimeter every time I change the batteries. 27' does seem a good enough average though. Just a thought...

[gridlox]

You musta read my mind...

 

Put in a fresh set of batteries before I went out yesterday morning.

 

Got new set of coordinates than on the previous visit.

Set my mark.

Walked about 100 yards away and came back and it put me within 8ft of the spot.

 

Went back by late yesterday afternoon - 15ft off.

 

Stopped by this morning on the way to a Saturday morning breakfast buffet - 4ft!!

 

I think the latest ones are good to go!

 

Now I just gotta finish the cache to place it!!

 

Thanks guys!

 

D-man