Just Bought My Gps - Help Me - Is This Performance Good?

[pluto2se]

Hi!

 

I just bought my first GPS - a bluetooth GPS module for my symbian phone, a xaiox 32channel instantfix, bought it on ebay from dealcat.de. It does not have EGNOS/WAAS support but has 32 channels and is advertised to do <5 M accuracy under open sky 90% of the time. That's why I choosed it over a EGNOS capable receiver since I've read all too much about EGNOS not making a noticable difference in europe.

 

I'm new to GPS and haven't got too much experience yet of the GPS system. My question is therefore, is the performance I'm getting good, or bad? or just average? I feel somewhat concerned about it.

 

I've done some geocaching, visited about 5-6 caches so I'm starting to get a feel for it and my gps device.

 

Under an open sky my GPS usually points me to a position within 2-7 meters of the cache spot. Not quite the "<5m 90% of the time" specified.

 

The real problems started when I went into the woods here. The device was pretty much completelly unable to sense my movement and give me a course. If I stood still for a long time it could sense my position but of course not give me a course. This was a real anticlimax, I don't know if I could have navigated out of the forest like this if I wouldn't know where I was, which I did thank god. The forest was pretty dense but not extremely dense. It got better when I got to an open spot within the woods but except for that place msot of the time it wouldn't sense my movement at all.

 

Another situation: A cache in the city, by the wall of an old castle (stone walls). Everything pointed fine until I got close to the walls, then things got bad, there was no real way of getting a direction and the gps only sensed my movement at certain spots. Perhaps the signal bounced on the stone walls, I don't know. Once again an anticlimax. I had a feeling for where the cache was, and I was right, butwithout that feeling I would probably have a search radius of at least 20-40 meters or so!

 

Finally I find the gps pretty "slow" on sensing my movement. Say I have a fix and start walking, it takes quite a few seconds before it senses my movement and gives a course and it takes even longer before the course is actually pretty correct. If I stop and walk the opposite direction it once again takes quite some time before it senses the change.

 

What do you think of this experience? Did I get a bad brand or model of my gps receiver or is this just "the way it is"? I'm quite a perfectionist perhaps but I expected abit more. Should I have bought a EGNOS capable receiver instead? (despite the fact I've heard alot of that it doesn't do a big difference in europe)

 

Please give me your reactions and experience on this! Can I get better results from another device?

 

regards,

Kristian Tigersjäl

[+briansnat]

Under an open sky my GPS usually points me to a position within 2-7 meters of the cache spot. Not quite the "<5m 90% of the time" specified.

 

2-7 meters is pretty good. Accuracy at the cache of up to about 15 meters is very common and nothing to worry about.

 

The real problems started when I went into the woods here. The device was pretty much completelly unable to sense my movement and give me a course.

 

All units have some degree of reception issues in the woods. Leaves block signals. That said from what you say, your unit seems to perform worse than most other units under trees. Even an eTrex Legend, which doesn't have a great rep for reception under trees, will keep a lock (albeit weak) most of the time under trees. When it does lose it, it will usually get it back within a matter of a few seconds.

 

A cache in the city, by the wall of an old castle (stone walls). Everything pointed fine until I got close to the walls, then things got bad, there was no real way of getting a direction and the gps only sensed my movement at certain spots. P

Cliff sides and tall buildings give all GPS units fits. A small wall shouldn't.

Depending on how high these walls are, this may or may not be an issue.

 

Finally I find the gps pretty "slow" on sensing my movement. Say I have a fix and start walking, it takes quite a few seconds before it senses my movement and gives a course and it takes even longer before the course is actually pretty correct. If I stop and walk the opposite direction it once again takes quite some time before it senses the change.

 

How many seconds are "quite a few"? Most units I have will take anywere from a few, to about 30 seconds to sense a change in direction. If its consistently more than that you may have a problem.

 

What do you think of this experience? Did I get a bad brand or model of my gps receiver or is this just "the way it is"? I'm quite a perfectionist perhaps but I expected abit more. Should I have bought a EGNOS capable receiver instead? (despite the fact I've heard alot of that it doesn't do a big difference in europe)

 

I don't think you got a bad brand, but you might be asking a bit more of it than it was designed for. I don't think these cell phone units are really meant for use in the woods. They're more for finding your way around cities and towns. One way to help with reception is to make sure its always positioned in a manner where it will get best reception. This depends on the kind of antenna in the unit. You can experiment with your unit to figure this out. Also, make sure it has a clear view of the sky and isn't inside your pocket or pack, or even very close to your body (e.g. on a belt clip), as your body can block signals.

[+briansnat]

Moving to appropriate forum