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Outdoor Products |
GPS Sat Nav Review of the Garmin etrex LegendJust before our Dorset holiday in 2005 we purchased a
portable Global Positioning System (GPS) Satellite Navigation receiver
(Sat Nav). We figured that such a gadget was a useful
accompaniment on our walks. Here's our review...
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We try it on the steam train |
We try it on our walks
We used the Sat Nav unit on our Hardy's Monument walk to see if it
could get us back to the cottage by using the TracBack feature.
This works by saving the breadcrumb trail we left on the outward
journey and selecting 'TracBack' from the saved track menu. The
time and miles to destination are shown by default on the navigation
page with a compass, we customised the display to additionally show the
ETA and To Course on the display, the latter shows how many degrees to
turn to maintain the correct direction. It worked brilliantly, we
purposely walked past a point where we should have turned right and the
Sat Nav unit compass arrow swung round to show the correct direction in
an instant. The ETA was within 1 minute too, not bad when the
trip computer has to work this out by constantly updating our speed
computation, including stops for a swig of water and a pee (Mike)!
However, we found a problem using GPS on our
walk along the South West Coast
Path at Lyme Regis. As the walk was mainly in dense woodland,
the Sat Nav unit had trouble picking up the satellites signal. It
needs to receive at least three to work, the trees blocking its view of
the sky and the resultant trail was very patchy. We didn't try
the TracBack, but we expect it would have had trouble following such a
broken trail.
On our Fleet walk,
also along the S. W. Coast Path, the trail was complete as the footpath
was well out in the open. That was good for the Sat Nav unit, but
not for us in the hot hot sun! This was a circle route and the
GPS really came into its own when, having been forced along some
twiddly bits, we came out to a little road and our sense of direction
said to turn right. The GPS showed the start of our trail (where
we had parked the car) to be to the left, thus saving us from going
completely in the wrong direction!![]()
An issue that manifested itself on our walks was with having to hold the Sat Nav unit in your hand all the time in order to receive a signal. This became a bit tiresome and sometimes awkward when needing both hands to cross a style, for instance. We tried carrying it in a bumbag and at the top of Mike's (why do I always carry all the stuff) backpack, but in both cases the GPS signal was too poor, even in open country.
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We try it in the town |
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Some subsequent tests we did in Brighton showed us to be just north of the main A259 coast road when we were out at sea at the end of the quarter mile long pier! This inaccuracy rather makes it superfluous of GPS being capable of an accuracy to, typically, 12 meters and certainly doesn't enthuse us to buy the MapSource CDs to give street level mapping. Would it ever show us in the right street? Come to that, would it receive enough satellite signal in town anyway??
Batteries
We've added this bit as we experienced problems in this area
too. The Sat Nav receiver takes two 'AA' sized batteries, either
dry or rechargeable cells. We used modern Nickel Metal Hydride
(NiMH), convenient for us as our digital camera and MP3 player use the
same cells. We found that fully charged batteries barely lasted
the day out using the Sat Nav unit from, typically, 10am until
6pm. There's a battery saver mode which did extend battery life,
but the trade off was less frequent satellite signal checking,
resulting in even more patchy trail drawing. We tried
setting the backlight to the minimum too, to conserve power.
However, we needed to carry spare cells (fortunately a battery change
doesn't loose data as it's stored on internal flash memory) to ensure
continued operation all day. Keeping enough batteries charged for
a day's walking became a logistical challenge with only one charger
able to charge a pair of NiMH's for 8 hours at any one time. Some
nights Mike (why me!) was changing batteries in the middle of the night
to provide enough for the next day (yawn!). Of course, the easy
solution is to buy another charger, they're cheap enough after all, but
surely if mobile phones can easily last in excess of one day on a
charge then so should a little GPS Sat Nav unit.
Other features briefly
The Sat Nav receiver also has a calculator, area calculator
(eg. walk round a field and calculate the acres), distance calculator,
hunt and fish calculator, calendar with notes, sun/moon set/rise times
(can be projected for different locations and days), a favourites store
and a find feature, eg. find a town which it then describes.
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Good Points... |
Bad Points... |
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Our overall
conclusions
The Garmin etrex Legend GPS Sat Nav unit we used does have
some very useful features for walkers, such as its ability to get you
back to your starting point or to guide you to a pre-determined
point. It also provides reassurance that you're going in the
right direction when otherwise you'd have no idea.
We do have some serious concerns regarding its ability to correctly
show the position on the Basemap, plus its ability to receive a
consistent satellite signal in wooded and built-up areas. Not all
walking is done along open paths!
We suspect the same situation here as experienced with cell phone
technology in the late 1980s. The system was initially designed
for vehicle use, using an external aerial. Cell coverage would
drop out with early handheld portable phones. The situation will
surely improve with satellite strength and coverage, making handheld
GPS a better proposition in say, a few years time. There's also
the new Galileo navigation system in development, see links
below. An early adopter of technology is often disappointed.
For now, by all means purchase a handheld GPS Sat Nav receiver, but
beware of its limitations and be sure to take an old fashioned paper
map with you too!
Left. The trip computer page showing trip and total miles, moving and stopped time and max and average speeds. The 'speed' field on the left only registers when moving.
Check out our updates
to this review in following years.
You may also like to see how we use Sat
Nav for Geocaching.
You can find the Garmin International
website at: www.garmin.com
Other brands of Sat Nav include TomTom and Magellan. Also there's GPS software
available for mobile devices.
GPS related website resources and RSS feeds:
GPS: The New Navigation - explains how GPS works via an online game
or computer app.
OS Net - resource for the precise GPS user in
Great Britain.
GPS
Receiver Information - reviews and information on GPS receivers.
GPS
training - UK training courses in global positioning systems.
Geocaching - all about the worldwide treasure hunting GPS hobby.
Galileo
- new European navigation system in development which
uses 30 satellites to drastically improve signal availability and
positional accuracy.
What is Galileo - BBC's Q&A on Europe's
Galileo project (and further links).
Please inform us if you find deadlinks or dead RSS feeds above.
© micbinks 2005. Please ask permission if you wish to reproduce any of this content in full or in part.
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