I bought an old Garmin eTrex Legend C just to see if I needed a GPS.
It doesn't work well under trees, and since my main activity is
walking/running in forests, that's a bit of a drawback.

Do newer systems cope better, or is the problem intrinsic in the
frequencies used? Might the new European system fare better? Is it
ready, or close, yet? (Displaying my wealth of ignorance here).

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

Swifty wrote on Oct 23, 2010:

> I bought an old Garmin eTrex Legend C just to see if I needed a GPS.
> It doesn't work well under trees, and since my main activity is
> walking/running in forests, that's a bit of a drawback.
>
> Do newer systems cope better, or is the problem intrinsic in the
> frequencies used? Might the new European system fare better? Is it
> ready, or close, yet? (Displaying my wealth of ignorance here).
>
>

Yes, the problem is intrinsic in the frequencies used - tree foliage acts as
a very good screen. However newer systems do cope much better with weak
signals - they will not usually lose contact under tree cover, but the
accuracy is much degraded

--
Mike Lane
UK North Yorkshire
mike_lane at mac dot com

"Mike Lane" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) dia.com...
> Swifty wrote on Oct 23, 2010:
>
>> I bought an old Garmin eTrex Legend C just to see if I needed a GPS.
>> It doesn't work well under trees, and since my main activity is
>> walking/running in forests, that's a bit of a drawback.
>>
>> Do newer systems cope better, or is the problem intrinsic in the
>> frequencies used? Might the new European system fare better? Is it
>> ready, or close, yet? (Displaying my wealth of ignorance here).
>>
>>
>
> Yes, the problem is intrinsic in the frequencies used - tree foliage acts
> as
> a very good screen. However newer systems do cope much better with weak
> signals - they will not usually lose contact under tree cover, but the
> accuracy is much degraded

I think that it is that newer systems will track up to 12 satellites (the
maximum visible), whereas older systems only tracked the [best] 5. Under
tree cover the most easily visible satellites near overhead will jump in and
out of visibility, so with just 5 the fix is often lost altogether, whereas
with 12 the fix is maintained albeit with reduced accuracy.

>
> --
> Mike Lane

R. Mark Clayton wrote on Oct 23, 2010:

> I think that it is that newer systems will track up to 12 satellites (the
> maximum visible), whereas older systems only tracked the [best] 5. Under
> tree cover the most easily visible satellites near overhead will jump in and
> out of visibility, so with just 5 the fix is often lost altogether, whereas
> with 12 the fix is maintained albeit with reduced accuracy.

Garmin gps units have had 12 channel receivers for years - certainly long
before the first eTrex came out.

--
Mike Lane
UK North Yorkshire
mike_lane at mac dot com

On Sat, 23 Oct 2010 22:55:39 +0100, Mike Lane
<(E-Mail Removed)> wrote:

>Garmin gps units have had 12 channel receivers for years - certainly long
>before the first eTrex came out.

The GPS12XL, 1998?

--
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather

Alan White wrote on Oct 24, 2010:

> On Sat, 23 Oct 2010 22:55:39 +0100, Mike Lane
> <(E-Mail Removed)> wrote:
>
>> Garmin gps units have had 12 channel receivers for years - certainly long
>> before the first eTrex came out.
>
> The GPS12XL, 1998?
>
>

The first gps I ever owned

--
Mike Lane
UK North Yorkshire
mike_lane at mac dot com

On Sun, 24 Oct 2010 08:59:00 +0100, Mike Lane
<(E-Mail Removed)> wrote:

>The first gps I ever owned

Mine was a GPS40 which I bought in 1994. It still works but I prefer my
Colorado :-)

--
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather

On Sat, 23 Oct 2010 08:05:56 +0100, Swifty <(E-Mail Removed)>
wrote:

>Do newer systems cope better, or is the problem intrinsic in the
>frequencies used?

Thank you all for the answers.

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

"Swifty" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I bought an old Garmin eTrex Legend C just to see if I needed a GPS.
> It doesn't work well under trees, and since my main activity is
> walking/running in forests, that's a bit of a drawback.
>
> Do newer systems cope better, or is the problem intrinsic in the
> frequencies used? Might the new European system fare better? Is it
> ready, or close, yet? (Displaying my wealth of ignorance here).
>

My iBlue 747 Bluetooth GPS is very much better at receiving signals than my
Geko201 which I expect is similar to your eTrex. The iBlue will work under
trees, which is more than can be said for the Geko. The iBlue also gets a
lock very much more quickly. Tracks that I have recorded when under trees
have been good. The iBlue uses a 66 channel MTK chip.


--
Michael Chare

"Swifty" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>I bought an old Garmin eTrex Legend C just to see if I needed a GPS.
> It doesn't work well under trees, and since my main activity is
> walking/running in forests, that's a bit of a drawback.
>
> Do newer systems cope better, or is the problem intrinsic in the
> frequencies used? Might the new European system fare better? Is it
> ready, or close, yet? (Displaying my wealth of ignorance here).
>
> --
> Steve Swift
> http://www.swiftys.org.uk/swifty.html
> http://www.ringers.org.uk

It's a "satellite" BTW.