View previous topic :: View next topic |
Author |
Message |
goon525 Regular Visitor
Joined: Aug 25, 2005 Posts: 75
|
Posted: Sun May 03, 2009 4:09 pm Post subject: Some observations after intensive use |
|
|
Just back from a few days walking on the Isle of Wight, first time that my Satmap has been in use intensively for several days on the trot. A few observations:-
1 The rechargeable battery pack has proved just fine, full day walks ending with three blobs out of four still showing on the meter. This with machine and screen (at 60% brightness) left on all of the time. I don't know how accurate the blobs are, but I'd be pretty confident that it still had several hours left in it. A few hours recharging had it working fine next day.
2 As others have experienced, it can be sluggish getting first fix. Once it has the fix, it sticks to it come what may, but it's a bit embarrassing being beaten to it by a chep'n'cheerful early generation Garmin. It does seem to take ages after it's seen even eight or nine satellites to fix the position. This was a bit unpredictable though - at other times, it was perfectly fast. I suspect this could be fixed easily enough in firmware/software if Satmap wanted to.
3 Also as others have experienced, it consistently over-reads the distance walked. I got into a habit of hitting 'Stop' only for the longer lunch-break, not for five or ten minute stops. At the end of walks of between eight and twelve miles, I would say it had over-read by around 7%. Cheap'n'cheerful Garmins did better. Intriguingly, turning the track into a route at the end left one with pretty much a spot-on result. I don't know if this is a case of two errrors cancelling each other out, but again wonder if it could be fixed.
4 I've bought some spare covers, but not yet used the. Does anyone have any luck with materials to get rid of scratches on their top covers?
5 Notwithstanding the odd niggle, it's a great device which aroused a lot of interest and some envy amongst fellow walkers. |
|
Back to top |
|
|
BigPerk Frequent Visitor
Joined: Sep 06, 2006 Posts: 1618 Location: East Hertfordshire
|
Posted: Sun May 03, 2009 6:45 pm Post subject: |
|
|
Re (4) - thread "Scratched screen" may be of interest. I think there may be other relevant threads if you want to do a search. _________________ David
(Navigon 70 Live, Nuvi 360) |
|
Back to top |
|
|
mikealder Pocket GPS Moderator
Joined: Jan 14, 2005 Posts: 19638 Location: Blackpool , Lancs
|
Posted: Sun May 03, 2009 7:52 pm Post subject: |
|
|
Toothpaste or Duraglit silver polish can be used to polish out smaller scratches, if you manage to make a real mess of the outer shield screen it is replaceable - Three screens cost around £15 IIRC - Mike |
|
Back to top |
|
|
goon525 Regular Visitor
Joined: Aug 25, 2005 Posts: 75
|
Posted: Sun May 03, 2009 9:21 pm Post subject: |
|
|
Thanks, Mike. I've bought the set of three replacements but am quite keen to get a bit more use out of my first one first! Paid a bit less - around £12 at Amazon. I'll try the toothpaste idea - suspect Duraglit would cost me as much as a new screen. Thanks also to BigPerk. |
|
Back to top |
|
|
4ndynorfolk Regular Visitor
Joined: Jul 02, 2008 Posts: 237 Location: Norfolk
|
Posted: Sun May 03, 2009 9:55 pm Post subject: |
|
|
I have had success with DISPLEX mobile phone polish. I have used it for a number of years on mobiles and other lcd displays.
I had to order some more this weekend. Mobilefun have free p&p this weekend. |
|
Back to top |
|
|
djhpk Occasional Visitor
Joined: Jan 14, 2008 Posts: 28 Location: High Peak
|
Posted: Mon May 04, 2009 7:19 pm Post subject: Some observations after intensive use |
|
|
goon525 said
Quote: | Also as others have experienced, it consistently over-reads the distance walked. I got into a habit of hitting 'Stop' only for the longer lunch-break, not for five or ten minute stops. At the end of walks of between eight and twelve miles, I would say it had over-read by around 7%. Cheap'n'cheerful Garmins did better. Intriguingly, turning the track into a route at the end left one with pretty much a spot-on result. |
I beg to differ. If you put a track file from the Active 10 into Memory Map and check the track length you will find that it it agrees almost exactly with that given on the Active 10 itself. If you then convert the track to a route with Memory Map, you will find that the route length is reduced just as it is when you carry out the same operation on the Active 10.
This reduction is simply a consequence of using less data points to define the shape of a "wiggly" line. The more data points that you have, the more accurate the length estimate will be (unless all the data points are on a great circle).
So, the question is "why is the Garmin under recording the track length?" and the answer is probably that it is not recording track data points as frquently as the Active 10! |
|
Back to top |
|
|
goon525 Regular Visitor
Joined: Aug 25, 2005 Posts: 75
|
Posted: Mon May 04, 2009 8:12 pm Post subject: |
|
|
Sorry, but I can see the Satmap adding distance when I am standing absolutely still. As I said, the value of this over a longish walk seems to be about 7%, though I can't prove this scientifically. I'd be interested to walk a measured mile somewhere with it on, though!
My conjecture is that the effect of this over-reading roughly equals the 'cutting corners' under-reading when you turn a trail into a route. Two opposite errors are roughly cancelling each other out. |
|
Back to top |
|
|
philpugh Lifetime Member
Joined: Dec 28, 2005 Posts: 2003 Location: Antrobus, Cheshire
|
Posted: Tue May 05, 2009 2:10 pm Post subject: |
|
|
goon525 wrote: | Sorry, but I can see the Satmap adding distance when I am standing absolutely still. As I said, the value of this over a longish walk seems to be about 7%, though I can't prove this scientifically. |
There is always a little 'wandering' when stationary with GPS receivers. The better the fix (ie more sats and good spread over the sky) the less this will be. Unfortunately this does affect walking more than cycling/driving/flying in that order as the distance of the wandering is usually quite small (possibly a couple of metres each log interval but often less). If you are stopping for a significant time (eg lunch) then it is probably best to stop logging - but short stops (or "view breaks" as we older walkers call them ) shouldn't be too troublesome.
Now I'm prepared to be shouted down here but I believe that most GPS units calculate distance in 2D - that is they don't take into account ascents/descents - but that is the same if you measure the distance on an OS map with one of those little wheel thingies (they must have a name but I have forgotten it). So a walk with a lot of steep ascent/descent will be under measured for distance over the ground for those sections. If GPS units do take into account changes in height then there is a bigger problem - their altitude accuracy is appaling and would render distance calculations irrelevant. _________________ Phil |
|
Back to top |
|
|
Not_lost_yet Occasional Visitor
Joined: Apr 26, 2009 Posts: 16 Location: Nottingham UK
|
Posted: Tue May 05, 2009 2:37 pm Post subject: |
|
|
4ndynorfolk wrote: | I have had success with DISPLEX mobile phone polish. I have used it for a number of years on mobiles and other lcd displays.
I had to order some more this weekend. Mobilefun have free p&p this weekend. |
Based on this post I have done the same whilst P&P is free. Thanks for the info |
|
Back to top |
|
|
cosmiccowboy Occasional Visitor
Joined: May 20, 2008 Posts: 22
|
Posted: Wed May 06, 2009 11:52 am Post subject: |
|
|
Not_lost_yet wrote: | 4ndynorfolk wrote: | I have had success with DISPLEX mobile phone polish. I have used it for a number of years on mobiles and other lcd displays.
I had to order some more this weekend. Mobilefun have free p&p this weekend. |
Based on this post I have done the same whilst P&P is free. Thanks for the info |
Ditto.
I hope you're on commision.
Thank you.
cosmic |
|
Back to top |
|
|
|
Posted: Today Post subject: Pocket GPS Advertising |
|
|
We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?. Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!
|
|
Back to top |
|
|
|