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My field
report detailed much of the functionality of the Magellan SporTrak Color
GPS receiver. For this Long Term Report I am focusing on some
specific observations I either did not notice before the Field
Report, or wanted to explore further before reporting on them. For
details on the functionality, buttons, and screens please see my Field
Report.
In this
report I focus on three major areas: Positional
Data, Basemaps and Topo Maps, and
Accuracy and Signal Acquisition.
Positional Data
There are
three types of positional data that can be used with the Magellan
SporTrak Color: Waypoints, Tracks, and
Routes.
Waypoints: Waypoints are individual single locations that
can be marked in the GPSr. Waypoints can be uploaded
via different types of software such as EasyGPS, MapSend Topo,
and National Geographic Topo. They can also be entered manually
when the unit is not obtaining a signal, or they can be entered with
all data filled in while standing at a particular location and having
a satellite lock.
Manual waypoint marking: I hit the mark button (the button marked with
a pushpin icon) and the mark screen pops up.
On this
screen I have a choice. If the unit is locked on, the coordinates
that are shown mark my current location. If I am on a hike and
want to mark a trail junction, campsite location, or any other
feature, I use this. The waypoint is given a default name in the
form of WPTxxx, but the user can edit this name to be anything.
I can choose an icon to denote the point when I am viewing the map screen,
and the coordinate system can be customized - in this case I
have it set to Lat/Long. In addition I can add the elevation
and any notes that are relevant for the waypoint. If I do not
want to mark the location where I am standing I can manually edit the
position to whatever location I like. After saving it the
waypoint is saved to the unit's database where I can access it
via menu features.
Uploading: A quicker way to enter waypoints, especially
when there are more than one or two, is via software. I have
used three different types of software to upload waypoints: Magellan
MapSend Topo, National Geographic State Series Topo: California, and
EasyGPS. Each software has a simple transfer process,
where I simply have to connect the GPSr unit to the computer using the
data cable, turn it on, and then click on a send button in
the software. Any selected waypoints are then uploaded to the
unit.
On the Magellan MapSend Topo software, uploading waypoints
will delete any waypoints already uploaded to the unit, so I have to
be careful to first transfer any waypoints I want saved from the GPSr
to the software, then upload everything including any new waypoints back
to the unit. Neither EasyGPS or National Geographic seem to have
this problem. Although manageable, it is tedious and I have
lost waypoints on more than one careless occasion. To be fair, the
software does warn about this before the transfer is okayed by the end
user. I use EasyGPS in conjunction with the geocaching
website. For any given geocache I can download a waypoint file
(.loc or .gpx). I then use EasyGPS to transfer these waypoints
quickly to the SporTrak Color. I prefer EasyGPS when transferring
large numbers of single waypoints because it transfers quickly and
the software is simple and quick to open because it is not a
mapping software, simply a tool for managing many waypoints.
For routes, the mapping software is more useful, but I am getting ahead of
myself.
Tracks: The SporTrak Topo records a track as
the unit moves. When the unit is turned off, the track picks back up
where it left off. This means that if I have the unit on in Phoenix
and then turn it off, hop on a plane to San Francisco, then turn the unit
back on, the track log will show a straight line between Phoenix and San
Francisco. This also means that when the unit is left on during a
hike, it will record the entire hike, including twists, turns, and
pauses. A track log can be reversed into a backtrack so that it can
be followed back to a trailhead. The level of detail can be set
using the Map Setup menu on the GPSr.
Routes: A route can be a very simple function
on the SporTrak Topo. I'm here and I want to go there. For
this, I use a GoTo route. This is a one-leg route that points me in
a straight line to the place I want to go.
However, routes can be more complicated than this. What if
I want to go to point A, but I want to pass through point B, C, and
D, which do not lie on a straight line between me and point A, on my
way? Well, the SporTrak Color has the ability to make multi-leg
routes with a bunch of waypoints. As the manual describes, think of
it as a bunch of one-leg routes strung together to form a larger more
complicated route. The use and management of these type of routes is
surprisingly easy using the unit alone, and even easier when combining it
with a mapping software. There is an option to save a recorded track
to a route, but due to the use of actual waypoints instead of temporary
nodes, it is not as accurate as simply viewing the track.
I've set up an example of the difference among the three
types of Data below. All images are screenshots from
the Magellan MapSend Topo program. The first image below shows
the loop drive through Red Rock Canyon, a popular rock climbing area
outside of Las Vegas, with the basic data contained in the MapSend Topo
software. Interestingly, a portion of the loop drive road
is missing from the map - the road should loop all the way around back to
Blue Diamond road. This part of the road is also missing from other
software consulted, including the National Geographic Backroads Explorer
also being tested by BackpackGearTest. No interaction with
the SporTrak Color occurs in this image.
This second image shows the track that was recorded as we
drove the loop, uploaded to the MapSend software from the
SporTrak. It fills in the missing part of the road, and over the 13
mile (21 km) journey it recorded 85 track nodes (a term used by
the MapSend software). These nodes are not recorded in the database
as waypoints, but they make up the track. Using the software I can
delete any nodes I wish to from the track, however I do not have this
management ability directly in the SporTrak. In this example, I
hadn't cleared the track since being in the Grand Canyon the day before,
so the entire track included 130 nodes and spanned the South Rim of the
Grand Canyon to Red Rock Canyon. I deleted the nodes up until the
one at the beginning of the Red Rock Canyon loop. The tiny loop on
the right side of the image is a visit to the restroom at the Visitor's
Center where I kept the SporTrak on.
The third image shows the track
converted into a route, which is done on the SporTrak Color by going
to the Track menu -> Save Track to Route. The route is made
up of waypoints rather than nodes, and I can access each waypoint
individually within the unit's database to make notes or changes. On
this particular image, the route built from the track is made up of the
waypoints that are named T01Pxx, the default which shows that this route
was built from a track. There are far fewer waypoints in the route
than nodes in the track. For details, tracks are more useful than
routes. The other waypoints in this image, all beginning with GC,
are geocaches that I had uploaded to the unit using the EasyGPS
software. They appear in the MapSend software because when I upload
waypoints from the SporTrak to the software, I cannot pick and choose
which ones I would like - it uploads all of the waypoints in my GPSr.
Basemaps and Topo Maps
The road coverage in the installed base maps is
disappointing at best. I have often been on major roads that do not
exist on the basemap.
One example is the intersection of Page Mill and
Foothill Expressway just down the road from my office. The
basemap shows Foothill coming to an end where it intersects Page
Mill. Unfortunately, Foothill Expressway does not actually end
at this intersection as the base map shows, and actually continues
for several miles with the name Junipero Serra. Junipero Serra
is a two-lane paved road in this area (Foothill Expressway is a
four-lane divided road), but it has existed for years and is a major
access road for Stanford University. This is not the only case of
missing major roads I have noticed, but it was the first and most
surprising one.
I have found that if I want more comprehensive road data for
any area I must upload the topo of the region from the Magellan MapSend
Topo software. This software package includes a larger amount of
road data, including the type of road data that is truely useful to
me.
Now, I'll use an example to compare the missing
major road in a populated area from above with the information
provided in the MapSend Topo software. This
example is in the Modoc National Forest in northern California,
in an area where I have uploaded the topo map to the GPSr. Modoc
National Forest is spotted with lava tube and ice caves, and
surrounds Lava Beds National Monument. Over the July
4th holiday weekend my husband and I headed up to Lava Beds to
explore some backcountry caves. Prior to the trip we used the
National Geographic State Topo software for the state of California
to mark and upload the waypoints of caves. I used the Magellan
MapSend Topo Software to upload topo maps for the region.
Many backcountry caves are accessible only by driving down
progressively smaller and less-cared-for roads. The last few
miles are usually on small two-tracks overgrown with brush that leave
lovely scratches along the side of my truck. Knowing what I know
about missing major roads on the basemaps, I didn't expect to have
these small 4WD roads show up on my SporTrak Color. I actually
didn't even expect to see the roads once I had uploaded the topo data
either. I was surprised to see that they were there.
Because there are so many unlabelled logging and access
roads scattered throughout the area, finding the correct turnoff to a
backcountry cave isn't easy. I had uploaded the National Geographic
Topo routes to the SporTrak Color prior to the trip, but
several didn't get transferred (I still don't know why). I
learned the lesson to always check to see that my upload was
successful before driving several hours into the middle
of nowhere. Unfortunately I was left without route info, but
was very surprised to see the backcountry roads on the topo map, some
even labelled with forest road numbers. While my husband drove,
I turned on the unit and watched our progress through the labyrinth of
backcountry roads, saving a track for backtracking, and being able to give
useful instructions like "the turnoff we want is 0.2 miles up on the
left" and "turn here, we are at the correct intersection" instead of
the normal "it might be the next left, but there might be roads that
aren't on the map, so maybe it isn't the next left - or maybe
it's the road we just passed a second ago" that we usually have to
deal with when using poorly labelled national forest maps. I
was able to navigate solely based on the map screen and watching the
little arrow icon move with us.
Signal Acquisition (including WAAS) and
Accuracy
Without a doubt, the most positive feature of the Magellan
SporTrak Topo is its ability to gain and hold a signal. It
locks on extremely fast and I never have to wait more than a few
seconds for a lock. As an example, a couple of months ago I
travelled to Michigan from California. While sitting as a
passenger in a car on the freeway I turned on the SporTrak Topo.
Since the last time I had acquired a signal I had been in California, I
went to the Initialization screens and reset my location to
Michigan. This is not necessary, but it can speed up the
satellite acquisition process. I held the unit up to the
window, and it locked on and gave me a position within 30 seconds, and
this was from within a vehicle moving at approximately 70 mph.
Similarly, I did this same process on a recent trip to
Arizona. Again, it took only seconds to lock on. I then drove
up to the Las Vegas area, but it was close enough that I did not
reinitialize the unit to Nevada. It still locked on
quickly.
On one occasion I had some trouble getting a signal. I
was out geocaching at a local park under clear skies with no trees in my
way. I had the unit displaying the map screen, and instead of the
little position-indicating arrow, it was only showing the hourglass icon
after several minutes. The hourglass icon indicates that it is not
locked on and is trying to obtain a position. I went to the
satellite status screen and nothing was there - there were no satellites
listed at all. I had no idea what was wrong and decided to
re-initialize the unit to California. It obtained the signal quickly
after that, and I have not had that problem since. A quick glance at
the FAQ on the Magellan website reveals that they know about this issue,
and what I did was one of the solutions listed.
Something I did not touch on much in my Field Report is the
WAAS satellite acquisition. The SporTrak Color GPSr is a WAAS
compatible GPS receiver. What is WAAS? It stands for the
Wide Area Augmentation System, but that doesn't help without further
description! The important thing to know is that WAAS greatly
improves positional accuracy by providing small corrections to the
standard GPS satellite signal due to things such as errors in satellite
orbits and atmospheric disturbances. Often it results in an accuracy
of under 3 meters (9.8 feet). There are two WAAS stations
in the United States - one on each coast - which relay correction
information to two (soon to be three) geosynchronous WAAS
satellites. The Magellan SporTrak Color has the ability to
obtain the correction signal from the WAAS satellites and therefore obtain
better positional accuracy than from GPS satellites alone.
Currently WAAS signal correction is only available in the United
States.
Most of my GPSr use has been in Northern California, from
San Jose north. I normally only see one WAAS satellite when I
lock on. Similarly, in Michigan I only obtained a 1-satellite
WAAS signal. I can see if I am locked on to WAAS satellites by going
to the satellite status screen where any WAAS satellite is marked in
red. However, down in Arizona and Nevada I almost always locked
on to both WAAS satellites. In addition, I would lock on to
about seven GPS satellites, easily putting my positional accuracy
at under 3 meters (9.8 feet). Being in the wide open desert
helps positional accuracy a lot!
The signal accuracy declines under heavy tree cover or when
I am deep in a canyon. However, I cannot think of one occasion
where the signal simply dropped, even in some tough conditions.
When the unit is on and first obtains a signal it is very difficult to
lose it without simply turning the unit off. As an example, I will
refer to some of my geocaching adventures. In some local (San
Francisco Bay Area) parks, I have searched for caches under heavy
redwood tree cover. Upon locating the caches I have been 'off' by
as much as 90 feet (27 meters) in positional accuracy, with an
average of about 30 feet (9 meters). Of course, the accuracy
depends greatly on the person who hid the cache and initially obtained the
position, but I tried to pick caches that had been found and positionally
verified several times for this little experiment. Doing the
same thing in wide open areas - the open desert, open fields, etc.
- the positional accuracy is usually well under 10 feet (3
meters), especially when the GPSr sees both WAAS satellites.
Conclusions
In order for this GPS receiver to be truly useful for a
backcountry navigator, it must have the topo maps uploaded. In fact,
I think the topo maps must be uploaded even to navigate basic city
streets, since I have seen several cases where major roads are missing
from the base maps. The color screen really shines when displaying a
topo map, and it is at these times that I am happiest with the
unit. Unfortunately, the Magellan MapSend Topo software does
not come with the SporTrak Color (it does come with the SporTrak
Topo) and must be purchased separately, adding a large chunk of money
to an already pricey unit.
As for the waterproof and rugged claim by Magellan?
Well, I have dropped the unit several times. It has been sprinkled
and dripped on a few times. I use the Magellan neoprene carrying
case (available on the Magellan website) and although the case is showing
some damage from repeated tossing into packs and dropped on the rocky
ground, the GPSr looks as good as new, I am happy to report. No
problems at all!
The Magellan SporTrak Color has many, many positive
features, including the satellite acquisition abilities, the feel of the
unit in my hand and convenience of the buttons, and the lovely color map
display. However, I cannot really trust the maps and still am
careful when following them. Overall I would recommend the SporTrak
Color to anyone looking for a good backcountry GPS receiver, but I would
do so with the caveat that they should also pony up the cash for the
MapSend software. I think the unit would be much more hiker-friendly
if the software were included by default, as with the SporTrak Topo
unit.
I must admit, this has been one of the most interesting,
fun, and difficult tests I have done. I have learned more than I
ever thought I would and am now a GPS junkie. Thanks a lot,
Magellan! |
