Colorado 300, mapping error and cliff

[+emptyaddress]

Hi,

 

I have a curiosity with a Garmin Colorado 300 and it’s insistence that I was half way down a cliff.

 

Specifically, I parked near Ladybower, grabbed a brew and planned to walk over the Alport Castles.

 

I power the unit on, let it gain a signal and after a couple of minutes set the car as way point 1.

 

Knowing the route I did not check it again for a few miles until climbing up towards Alport.

 

The mapping screen at 0.3 miles and every resolution below insisted I was in a gully (I was not) that I had crossed a river (nope) and after a short distance told my wife and I with a degree of surprise we were over the cliff edge (pretty sure not).

 

So, I turned the unit off, left it a minute, powered it back on, and the position was correct, our path correct and luckily it now told us we were at the top of the cliff.

 

So, having a look at the track on the PC, (after the power on it started a new track), the unit from the car park was consistently 200-300 feet out (for 2.5 miles I was apparently walking on the water of two reservoirs)?

 

So, what did I do wrong as with the odd exception of velocity spikes on an old eTREX Summit, I’ve never seen such a consistently wrong track (the route was right and following the real track all the way unit the restart, just in the wrong location).

 

After the restart it did not miss a beat.

 

Any pointers well received.

 

(GPS 2.6, App 2.4)

 

Regards,

 

Neil

[+emptyaddress]

Without wanting to bump a post, the waypoint I had set at the car park, was in fact 37.2 miles away from were we really were.

 

Strange day indeed.

[+Evshro & son]

Perhaps calibrating the compass would help???????

[+emptyaddress]

Sorry, should have said, compass and altimeter calibrated on site, must have been "one of those days"

[+g-o-cashers]

I notice significant error in my position at times with the Colorado. I first posted about it here weeks ago and I continue to observe it. I'm actually surprised that more geocachers haven't reported it but I had given in to thinking maybe it was something specific with my unit. Your issue sounds similar to mine in some respects.

 

Description is pretty much as I noted in my first post:

 

- At some point I notice that my position is off by 100-300' and that GPS accuracy is off (usually EPE is >60-70' but not always). The Colorado seems to get stuck with this obvious position error.

- If I stop and power cycle the Colorado my position jumps immediately back to where I think I should be and accuracy is way back up again.

- I've verified in multiple cases using satellite prediction software than PDOP was good at these times.

 

I think that this occurs after the CO starts cold and is exposed to difficult reception conditions. Many times I turn the unit on in the morning after being off all night and go immediately into the woods where reception is difficult. It almost feels like to me that some error in my position is getting averaged in when reception is difficult but when I have good reception again it takes a very long time (10-20 minutes sometimes) for the GPS to flush the error back out unless I power cycle. My 60cs would be much more likely to lose signal under these conditions but when signal did return I could trust it to be pretty good -- very seldom off by hundreds of feet for any length of time.

 

GO$Rs

[+emptyaddress]

Thanks for the reply, your conditions sounds exactly the same.

 

When the unit was switched off then on, it took me exactly to where is “should” be.

 

I spent a while trying to interpret the onscreen maps to fit the local geography, but being over the cliff was a dead (sorry for the pun) giveaway.

 

On this particular occasion, it was powered on during a snow storm, 40 miles away from home under the cover of trees in a valley where there is not even mobile phone reception, so holding a signal was good, but once we moved to the summit for the view I would have hoped that the track would improve.

 

Would turning on EGNOS help?

 

Regards,

 

Neil