View unanswered posts | View active topics It is currently 16 December 18 2:34 am



Post new topic Reply to topic  [ 10 posts ] 
GPS Readings 
Author Message

Joined: 26 April 03 11:29 am
Posts: 8
Location: Camden N S W
GCA Found:
GCA Hidden:
Post GPS Readings
We were out caching today, as all good cachers should do and the Lord and Master was getting mightily annoyed.
Why does the new GPS (Magellan Sportrak Map) jump around like it has ants in its pants? From the same spot we were constantly getting "it's over there, no it's over here, no it's up there, wait a minute, it's down there!"
Believe me it nearly went in the river. We spent 3 1/2 hours trying to find Team Chaos' "More" cache, for the second time I might add, all to no avail.
Does anyone else have this problem, or is it just us inexperienced cachers?
Your feedback would be very much appreciated. :(

Outlaws


03 May 03 8:46 pm
Profile E-mail
It's all in how you get there....
It's all in how you get there....

Joined: 28 March 03 6:00 pm
Posts: 2181
GCA Found: 0
GCA Hidden: 35
Post 
More, not a good cache to be learning the tricks on... that terrain can be tricky to get readings in. A GOOD tip is to let the gps settle for a while as you search, then look at it again, just place it on a rock or tree stump that is close to the ground zero. have a bit of a fossick then see what the gps is saying. you will find that this trick will be successful quite regularly. Also remember in a valley or under trees the signal reception is downgraded.


03 May 03 9:12 pm
Profile

Joined: 26 April 03 11:29 am
Posts: 8
Location: Camden N S W
GCA Found:
GCA Hidden:
Post GPS Readings
Hi there Swampy

Thanks for your prompt reply.

As soon as we read it we went "oh yea, that makes sense". Thanks for the tips, we're trying again tomorrow, so hopefully we'll have more success utilising your advice.

At least we got to see alot of the area, although we nearly ended up having a domestic, as the co-ords the Lord & Master converted from his new GSP for my old GPS were across the bridge & up in the bush (and I mean UP in the bush). About an hour later my GPS readings were spot on but not a cave in sight! Only to hear from across the river "I think it's here". As it turned out, the readings on his were correct (we think).

Anyway, still alot of fun, & very good exercise! (Though we probably won't be able to walk tomorrow!)


03 May 03 9:40 pm
Profile E-mail
It's all in how you get there....
It's all in how you get there....

Joined: 28 March 03 6:00 pm
Posts: 2181
GCA Found: 0
GCA Hidden: 35
Post hints and tips
No problem, we all help each other here.


03 May 03 9:45 pm
Profile
1550 or more caches found
1550 or more caches found

Joined: 11 April 03 12:34 am
Posts: 259
Location: Adelaide
GCA Found: 10
GCA Hidden: 6
Post 
Vertical surfaces (like cliffs and buildings) can cause sat signal reflections and consequently realy jumpy position info. If you leave your SporTTrak still (as Swampy says) it will start averaging to refine its positioning.
Another technique you can sometimes use in bad coverage areas is to move away slightly (say 20 metres or so) to a better signal spot and note the direction line to the cache - a compass helps, repeat this from a few other spots. The point where your direction lines intersect should be close to the cache.
But despite all this just accept that we all must have some purple :( in our lives!


03 May 03 10:37 pm
Profile E-mail
It's all in how you get there....
It's all in how you get there....

Joined: 28 March 03 6:00 pm
Posts: 2181
GCA Found: 0
GCA Hidden: 35
Post GPS readings
Another good point there Alex. Reflections from buildings and cliffs do play havoc with the signals, Took me ages to get lock-on in Sydney the other week when I was there. The manmade canyons don't help at all.

A compass will be a good investment as well, mind you a few cachers will say that you don't need one. I tend to now use my compass a lot less than when I first started out. BUT it is still part of my Sunday-go-caching outfit.

Oh and I forgot to add to my first statement, don't forget to pick up your gps after you have found the cache, you will do it as some stage, we ALL have and anyone who tells you different is bending their version of reality:wink:

Have Fun

Swampy


04 May 03 12:19 am
Profile
250 or more caches found
250 or more caches found
User avatar

Joined: 28 March 03 8:07 pm
Posts: 573
Location: Lane Cove,NSW
GCA Found: 16
GCA Hidden: 26
Post 
And your sunglasses... Five pairs and counting :-)


04 May 03 12:21 am
Profile E-mail ICQ WWW

Joined: 04 April 03 8:05 pm
Posts: 16
Location: Nanango, Queensland
GCA Found: 0
GCA Hidden: 0
Post 
Just checking....

Are both the GPSr's set for the same Map Datum (WGS84)...


04 May 03 5:28 pm
Profile E-mail

Joined: 26 April 03 11:29 am
Posts: 8
Location: Camden N S W
GCA Found:
GCA Hidden:
Post 
G'day Damian

Yep after a bit of confusion yesterday (I sent she who must be obeyed)
in the wrong direction.

We tryed waiting and letting the GPS settel down today and they both recorded the same readings even down to 0 meters to go when we were at GZ. so my faith in the black arts has been renewed.

Tony


04 May 03 7:24 pm
Profile E-mail
200 or more found
200 or more found
User avatar

Joined: 03 April 03 7:57 pm
Posts: 1267
Location: Crestwood, NSW
GCA Found: 21
GCA Hidden: 0
Post 
Apart from the usual averaging/triangulation tips mentioned already, here is an advanced tip:
Satellites near the horizon can often cause inacuracies (due to multipath distortion, scatter, antenna design etc etc), so it's handy to be able to get rid of these. Yes, sometimes you can have too many satellites!
Just look at your satellite tracking map, find the bearing and declination of any marginal ones on the horizon and position yourself behind a major object (tree, cliff, your head etc) that blocks only that satellite.
Only for the techno freaks and ultra paranoid, but it can help in some situations.

EcoDave :)


05 May 03 1:26 am
Profile E-mail WWW
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 


Who is online

Users browsing this forum: No registered users and 39 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Forum theme by Vjacheslav Trushkin for Free Forum/DivisionCore.