etrex 30 - ordered

Should have it mid next week.

Will report on its performance and how it well integrates GLONASS.

The leaves in the nearby forest are all down, however, so won't get a
feeling for acquisition in the woods until summer.

I also look forward to seeing how well the mag compass performs.

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On 11/19/2011 1:48 PM, Alan Browne wrote:
With the 2-axis compass, you just rotated the GPS to "calibrate" it. I
wonder what it done for a 3-axis compass?

Hint: You look a lot less silly twisting the GPS around in your hand to
do the cal then rotating your body. ;-)

I still use a real compass (Cammenga lensatic). It is far easier to fix
on the target when you have a sighting slot.

If you decide to get a Cammenga, the phosphorus version is fine for
civilian use. You just "juice it" with your flashlight. Given the price
of these compasses today, I suspect they are still made in the USA. The
phosphorus version will outlive you. The tritium version has a 12 year
half life. I'm not sure how long people keep them before deeming them
too dim to see at night. It has an electromagnetic damping scheme, so
there is no fluid inside it to deteriorate over time.

The GPS compass is useful only when you are moving so slowly that the
differential GPS reading is not accurate. When I first got the GPSmap60,
I did some testing before I considered it trustworthy. Basically just
navigation to a point. I found the compass was terrible. There is a
setting in the GPS to determine at what speed you allow the compass to
be used instead of differential readings (i.e. virtual compass). I set
it up so the compass was never used. The only time your movement on foot
is slow enough to need a compass is when climbing at a steep angle
(huffing and puffing), poor footing (slipping backwards), etc. For most
navigation, the differential location scheme is fine.

On 2011-11-19 21:34 , miso wrote:

I have an orienteering compass which is great for aligning on where to
go and less good on taking bearing lines to fix ones position.

I'd like to buy a thumb compass for orienteering. Not even any bearing
markings, just a rotating bezel. Smaller. No strings. Fast.


One day perhaps for long hikes.


Good points. However, the weakness of the GPS is that it determines the
track along which the receiver is moving. It is not relative to the
case of the receiver. So working with a map is tedious. Of course a
real compass is best for working with a map.

Neglected to mention I also look forward to using the baro alt on the etrex.



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wrote:
e

Actually, when navigating the sailboat, I more interested about where
I'm actually going rather than which way I'm pointing. I'm not saying
my compass isn't useful for sighting plotting bearings or steering to
a nearby destination getting close enough to see it. But I often quip
the 'compass is overrated' just to start trouble with the 'Old Salts'.

--- CHAS

On 2011-11-20 15:15 , HIPAR wrote:

As a pilot heading v. track is a very important distinction, esp. in a
crosswind approach.

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