32056REVISED: TED--IR for DeLorme PN-20 GOS
- Mar 30, 2007I went over this morning and fixed a few glaring errors (they always
glare the following day).
DELORME EARTHMATE GPS PN-20 DELUXE BUNDLE
TEST SERIES BY EDWARD RIPLEY-DUGGAN
March 30, 2007
NAME: Edward Ripley-Duggan
LOCATION: Catskills, New York State
HEIGHT: 6' 1" (1.85 m)
WEIGHT: 215 lb (97.50 kg)
I enjoy walking in all its forms, from a simple stroll in the woods to
multi-day backpack excursions. Though by no means an extreme
ultra-light enthusiast, from spring to fall my preference is to carry
a pack weight (before food and water) of 12 lb (5.5 kg), more or less.
In recent years, I've rapidly moved to a philosophy of "lighter is
better," within the constraints of budget and common sense.
PRODUCT INFORMATION AND SPECIFICATIONS
Year of Manufacture: 2007
Manufacturer's Website: http://www.delorme.com
MSRP: US$449.95 for deluxe bundle version (regular price March 2007,
from manufacturer's literature)
The GPS unit
Contents of basic GPS package: GPS receiver, neck lanyard, manual, USB
cable, 2 AA batteries, plus Topo USA version 6.0 (see below) and
various notices etc.
GPS casing: IPX-7 waterproof, impact resistant [so stated by manufacturer]
N.B. The IPX-7 standard is defined as "Protected against heavy seas -
Water projected at all angles through a 12.5mm nozzle at a flow rate
of 100 liters/min at a pressure of 100kN/m2 for 3 minutes from a
distance of 3 meters." This is handy to know for sea kayaking!
Color: Yellow and black
Stated dimensions: 5.25" x 2.43" x 1.5" (13 cm x 6 cm x 4 cm)
Measured dimensions: My measurements are congruent with those of the
manufacturer, allowing for the awkward shape
Listed weight, without batteries: 5.28 oz (150 g)
Listed weight, with 2 AA batteries: 7.04 oz (200 g)
Measured weight, without batteries, including SD [Secure Digital]
memory card: 5.25 oz (148 g)
Measured weight, with 2 AA batteries, including SD card: 7.25 oz (206 g)
Measured weight, with supplied lithium-ion rechargeable battery,
including SD card: 6.75 oz (191 g)
N.B. The measured weights are subject to the approximately .2 oz (6 g)
tolerance of my scale.
Screen size, stated: 176 x 220 [pixels] daylight-readable TFT [i.e.
"thin film transistor liquid crystal display"]
Screen dimensions, measured: 1.7" x 1.4" (44 x 35 mm)
Batteries: 2 AA, or lithium-ion rechargeable battery
Memory: 75 MB user-available internal flash memory
Extended memory: Will accept SD (Secure Digital) cards to 2 GB
capacity in slot behind battery
Supplied extended memory: One 1 GB SD card, with USB 2.0 SD card reader
Manual: 83 pages, included
I have avoided quoting the full technical specs here, as to most
readers this is mere jargon (much of it for me too, I may add). For
those who wish to know details of the chipset etc., I recommend the
DeLorme website. However, the following are likely to be of general
Operating temperature range: -20 C to + 70 C (-4 F to 158 F)
Storage temperature range: -40 C to + 85 C (-40 F to 185 F)
Antenna: Built in [i.e. no port for external antenna]
Data storage: Up to 10 tracks (10,000 points per track), 1000
user-defined waypoints. 50 routes
Topo USA Version 6.0
Companion software, from plastic case containing the program on CD and
the US map database on DVD. Included is a certificate for the download
of up to $100-worth of De Lorme's Aerial Data packets (for up to 400
sq km, 154 sq mi). There's also a small correction slip, as the
packaging mentions the wrong figure for the area of the downloadable
data. This software and the downloadable data (USGS quads, satellite
and aerial imagery) come as standard issue with the GPS as offered by
DeLorme, both in its basic form and in the two bundled versions. These
are the "Travel Power Kit Bundle" and the present "DeLuxe Bundle,"
about which more in a moment. There is a manual in PDF (Portable
Document Format) form included as a file on the disk, but (other than
a folding sheet with a "quick start guide" to assist with software
installation) no separate printed manual for the software.
Contents of the Deluxe Bundle
In addition to the items noted above, the Deluxe Bundle contains the
following. I have (with the exception of the rechargeable battery) not
weighed these various peripherals. Most are power supply cords of
various kinds, plus the SD card and card reader. They comprise a
comprehensive but slightly confusing array, and are unlikely to be
carried on a backpack, when simple replacement AA batteries will suffice.
CR-V3 lithium-ion rechargeable battery
Charging battery pack for the battery, with both A/C and 12-volt
Special eight-pin-to-mini-USB connector for the PN-20, required for
charging the Li-ion battery inside the GPS
12-volt in-vehicle cables, which connect the connector listed above
LCD protective film kit with three screen protector films and one
1-GB SD card
USB 2.0 card reader
Black nylon ditty bag for storing all of the above
The DeLorme Earthmate GPS PN-20
The unit was received well packaged and in sound condition. The GPS
receiver, manual, software and two AA batteries were housed in an
attractively printed box, which lists many of the features (both basic
and technical) of the GPS unit and the software. One point of note is
that the box states that a certificate for 400 square miles of
downloadable imagery is included. This is an error, as is noted on a
paper slip included in the Topo USA box. The correct figure is 400
The "Deluxe bundle" was separately housed within the package. A very
convenient black nylon pouch is included with this, which holds all
the various appurtenances once they are unpacked. This is a good
thing. There are a lot of them, some of which are indistinguishable
from the various other chargers, cables etc. with which our lives now
seem festooned, so to have a container solely for these is a plus!
As with most electronic devices, the DeLorme warranty is a bit more
limited than that for most outdoors gear. although in line with
warranties for most consumer electronics. If desired, the warranty can
be examined in full on the website (or in the manual), but the gist is
summed up in the first two paragraphs:
"DeLorme warrants that your Earthmate GPS PN-20 will be free from
defects in materials and workmanship for 1 year from the date of
purchase. If your Earthmate GPS PN-20 fails in normal use, DeLorme
will, at its sole option, either repair or replace the unit. DeLorme
reserves the right to either repair or replace the unit with a new or
refurbished unit at its sole discretion.
Such repairs or replacements will be made at no charge for labor or
materials; however, the customer will be responsible for any shipping
charges incurred to send the device to DeLorme. The repaired or
replaced product will be warranted for 90 days from the date of return
shipment, or for the balance of the original warranty, whichever is
longer. This warranty does not cover failures due to abuse, misuse,
accidents, or unauthorized disassembly or modification. Any repairs
not performed by DeLorme will void this warranty."
What is left a little unclear in the warranty text is how
out-of-warranty service is handled, and I'd love to see the manual's
text improved to clarify this. A GPS is a long-term investment, and I
would like to know details on out-of-warranty care.
While I was not an especially early adopter of GPS technology, I have
owned one for six or seven years, and I'm reasonably familiar with a
fairly wide range of handheld units. As to software, I've owned
another DeLorme product, 3-D Topoquads (now in version 2.0) for
perhaps ten years. I mention this because my perceptions of the
product will unavoidably be those of a fairly experienced user of both
GPS and basic mapping software.
I do feel that the controls of this GPS unit are well laid out. Even
if I did not have prior experience with similar units, it would prove
fairly intuitive to me, at least after I had read the manual and
mastered the basic concepts of GPS use. It is, after all, less
complicated than some advanced cell phones.
The PN-20 has proved easy for me to operate. In part this is because
of the way the firmware (the operating system for the unit) is
designed. There's not much functionality that's buried away below many
tiers of menus. An additional reason is that the controls have a
pleasing crispness to their operation. A button-press is accompanied
by a gentle electronically-generated click, which provides useful
auditory feedback. I have even used the unit wearing gloves (and not
especially light ones, at that). The clarity and resolution of the
screen display is excellent, as is the brightness, which is fully
controllable, another key factor in ease of use.
I had batteries loaded and my first GPS location fix within a
half-hour of having unpacked the unit after receipt. By the following
day I was using it to create a track with occasional waypoints, when I
took several hours off to do a backcountry ski jaunt. Certainly, for
anyone with some exposure to GPS technology, learning to use the PN-20
shouldn't be much of an issue.
At this point, let me sound a gentle note of caution regarding GPS
units in general. The GPS technology is revolutionary for wayfinding,
no ifs, ands or buts. Still, when I'm in anything approaching serious
backcountry terrain (which, the day of the ski tour I mention, I was
not), I navigate in the traditional manner: by use of map, compass,
cues taken from the terrain, and common sense. My GPS is usually with
me, and I may use it to track my progress for later examination, or to
mark (waypoint) the locations of anything interesting that I see so I
can return to those points in future. I'll certainly reach for it, if
it's handy, to help untangle a navigational error, but I do not rely
on it. The GPS is a powerful navigation tool, but I feel very strongly
that anything that can go wrong or lose power should never be the
sole, or even the primary method of wayfinding on difficult terrain.
It should not be the primary tool in circumstances where the
consequences of equipment failure could be serious. Here endeth the
The PN-20 is quite a bit chunkier, and marginally heavier than the GPS
I have been using. That's a black-and-white model, and the color
display (and brightness) of the DeLorme model were something I found
impressive from the outset. Unfortunately, owing to a defective
program installation disk I was unable to upload maps until I received
the replacement disk several days later, but even without that feature
operational, I found being able to see my track on the screen, so
easily discernible in color, distinctly useful. While I was out that
first day I saw a fisher, a very large member of the weasel family and
the first I'd ever seen in the wild, and it was a pleasure (and a nice
baptism for the unit) to waypoint the spot.
On a final note, the PN-20 was generally very much what I had expected
from DeLorme's literature about the unit (which I had, as an existing
customer, previously received by mail), and from their website.
Quality of instructions
As with any piece of electronic apparatus, the manual is key to
understanding how to operate a GPS. The PN-20 manual is, in my
estimation, well-written and comprehensive. There's a useful "Getting
Started" section, with the basics of battery installation and turning
the unit on for the first time. The functions of the buttons are
described here. There is, rather surprisingly, no diagram of the front
and back of the case, but as the buttons on the unit are generally
labelled or otherwise fairly obvious, this may have been deemed
unnecessary. although if I were a beginning user, I might consider
this a shortcoming. A labelled view of both front and back is shown in
this report. Various other basics of operation are discussed in this
introductory section of the manual.
After this, there's a section of "Scenarios." This is an excellent
idea. Before the nitty-gritty details, this shows how the GPS can be
used in three real-world settings. The activities selected are
geocaching, bird watching, and mountain biking. These examples of how
the GPS can enhance (or, in the case of geocaching, enable) these
pursuits was, I found, very helpful. This was particularly the case
with geocaching, which is an activity I have not pursued up until now,
and which I intend to investigate while I test the PN-20.
The balance of the manual describes the operation of the GPS on a
screen-by-screen basis. Using a book metaphor, DeLorme terms the
various operational screens "pages," pretty much standard terminology
with GPS units. The margin of the text in this section of the manual
provides screenshots as well as some helpful hints, highlighted in boxes.
I found the manual useful in answering a number of questions. The only
caveat that I have is that it isn't as well indexed as it might be.
However, it may also be downloaded from the DeLorme website in PDF
form, and it can then be completely searched on any word using Adobe
Reader's search functions. I've saved that to my desktop.
While the contents of the Deluxe Bundle are mostly pretty obvious, I
felt the documentation to be a little skimpy, but overall adequate.
There is a printed sheet identifying the various components of the
Travel PowerKit, together with instructions on how to insert the
charged lithium-ion battery, and how to use the charger itself. This
did leave me unclear on a few points, for example whether there is
there any reason why the plug prongs on the charger unit can't be used
instead of attaching the AC adapter? However, this is hardly crucial,
and the documentation is sufficient.
As the installation CD for the Topo USA software proved to be
defective, giving me CRC errors galore and preventing me from
installing the software, I had to call DeLorme's technical service for
a replacement. I was quickly routed to an operator. The subsequent
wait for a service technician turned out to be almost twenty minutes.
With a new product and a probable high volume of calls, this delay was
not unexpected, but the response would ideally have been swifter. The
technician, once I got through, was very helpful and courteous. I was
not able to disguise the fact that I was with BGT, as I needed to give
an invoice number. Having said this, he was perfectly obliging
beforehand, so I have no reason to think this revelation had any
effect on the outcome of the call! I received the new disk a few days
later. I have since had a couple of other occasions to contact
customer service, and the technicians have been unfailingly helpful.
If they read this, thank you.
Operation and Features
It's beyond the scope of this test to provide comprehensive
instruction on the operation of this GPS, or a description of the
technology of GPS in general. For the first, I recommend the PDF
version of DeLorme's manual. For the second, there's a wealth of
information on the Web on all aspects of the technology, from Antennas
to WAAS (I tried to think of a GPS term beginning with "Z," but
failed). Still, I do want to familiarize readers with the basics of
operation of the PN-20, so I can intelligently discuss my experiences
with the instrument. The controls of the unit, its buttons, pages and
menus, are not that different from many models of GPS, although (in my
estimation) the PN-20's ability to take on board maps and imagery puts
it in a whole new category.
First, here's the front panel of the GPS, with labels that briefly
describe the functions of the buttons. Bear in mind that the function
of some of these varies slightly according to the page/screen that's
Front panel of GPS
To power the GPS on, the small red "Power" button is held down for a
moment (the manual states for 1.5 seconds), and then released. The
DeLorme boot screen shows briefly, followed a few seconds later by the
Satellites page. The GPS immediately starts to acquire satellite
signals. Once on, if the "Power" button is held down for about 2
seconds, a slider bar appears, which enables the screen brightness to
be altered. If the button is just pressed briefly once while the
unit's on, the "power down" screen shows. When the Enter key is
pressed subsequently, the GPS will turn off. This two-button shutdown
seems to me to be a good idea, as it prevents accidentally shutting
the unit off. Holding the key down for 7 seconds resets the GPS.
Details of back of GPS
Above are two views of the back of the GPS case. On the left, the back
is shown held in place with two D-rings. These are attached to brass
screws, and turning the rings clockwise fastens the back tightly. Once
the back is screwed in place, the D-rings fold down flush and are
retained in position by two small projecting plastic ribs. To install
the AA batteries (or lithium-ion power pack) and the SD card, the back
must be removed, to expose the battery compartment (image on right).
To install the card, press on the small bar marked "PUSH." This
releases the SD slot, which then swings up (it is shown deployed in
this fashion in the right-hand image). The card slides into position,
with the contacts going in first and facing the interior of the GPS
(i.e. with the label on the card facing towards the user). Holding the
battery release ribbon out of the way (it tends to get in the way) the
slot is then pushed down until it clicks into place. The batteries may
then be installed (polarity as indicated in the diagram). The back is
then replaced using the screws attached to the D-rings, which are
folded then folded flush. The GPS is now ready for operation.
When I turned the GPS on for the first time (using the two supplied AA
cells, as the lithium-ion battery was not yet charged), I was quite
surprised at how quickly the unit provided an accurate first fix on my
location. I confirmed the accuracy in a mapping program, by punching
in the coordinates (the Topo USA basemap for my area was not yet
loaded because of the defective installation disk). A card laid into
the manual states that the process may take up to ten minutes the
first time used. I had a solid fix in about forty seconds, a figure
closer to what the manual states is normal for a warm start, i.e. with
much information (ephemeris, almanac, approximate time, partial
position) already present in the unit from previous use. It's possible
that the unit was tested in the factory, which would have resulted in
a faster first fix.
This speedy start may have been an anomaly, but I have been
consistently impressed, during my preliminary use of the PN-20, by the
speed of signal acquisition. It's generally capable of getting a
location swiftly even inside a building or in dense brush. As yet,
there are no leaves on the trees, but based by the quality of
satellite acquisition I am able to get on the ground floor of my
house, I shall be surprised if the heavy woodland canopy of the spring
and summer Catskills will cause any significant problems with
reception. I'll report on this, as this is an important consideration
with any GPS in the woods of the eastern US and elsewhere.
In order to give a sense of what it's like to use this GPS, what
follows are a list, with comments, of the main pages of the GPS,
together with a description of their layout and function.
The satellite page is shown displayed in the first image above (that
of the front of the GPS unit). This is the screen seen after the GPS
has booted. Unless the GPS location function is turned off from the
Setup menu (this can also be done by using the Menu button directly
from the Satellites page), the top section of this page shows a
circular view of the sky with superimposed directions (North up), with
approximate satellite positions. Below is a graph showing which
satellites are available, and the signal strength and status of each.
A blank means that the satellite is not yet being received. Red
indicates that it is being tracked, but no data has yet been received.
Green indicates that the satellite is being tracked, ephemeris data is
being received (one of several data streams from the GPS satellites),
and the satellite is being used for navigation.
Blue means much the same, but indicates that additionally the
satellite being tracked is providing WAAS correction, a technology
that enhances the accuracy of GPS position fixes. I have found that
the mere fact that the WAAS satellite (marked as satellite 138 by the
GPS, here on the East Coast) is shown as being tracked does not,
apparently, mean that WAAS correction data is being received.
According to DeLorme's manual, when WAAS correction is in operation,
the letters "WAAS" show at the top right of the screen, something I
have not often seen so far. When it works, almost all of the satellite
strength bars in the chart turn blue. The increase in accuracy that
I've noted is not especially dramatic. It increases from (say) +/- 40
ft (12 m) to perhaps +/- 15 ft (5 m), the latter being about the best
fix I've seen so far. This is a worthwhile improvement for some
purposes, but for general navigation (rather than identifying a very
specific location) it may not justify me enabling WAAS all the time.
The satellite page also shows the quality of fix (what DeLorme refers
to as 2-D and 3-D, which depends on the number of satellites
monitored), as well as the accuracy, expressed (as noted above) as a
tolerance: +/- [distance in feet or meters]. The font used to display
accuracy and fix type is, to my mind, badly chosen. It's an outline
font, which for those of us with less than 20/20 vision is generally
harder to read, especially when it's in a small point size.
Fortunately, much of this information can also be made available in
the Trip Info page, if desired, but it would be really helpful if
DeLorme would use a more legible font for this data.
The bottom of the screen has a bar that indicates battery strength.
For this to be accurate, it's critical that the correct battery type
is selected in the Setup page. If the wrong type is set, the battery
life shown is highly misleading. For example, if the indicator is set
to "lithium-ion battery" and a pair of standard alkaline AA cells are
used, the battery life will be shown as almost exhausted from the outset.
This is the heart of the GPS, its raison d'être. The Map page has an
extraordinary wealth of options, not all of which I am able to touch
on here. All of the configuration is done via the Menu key, which
provides access to three page-specific items: "Show info fields,"
"Measure distance," and "Map setup." The GPS has a pre-programmed
world highway base map (I'm using DeLorme's designations for the
various map types here). This is hardwired into the unit, and provides
only the most basic data. Shown are major cities, coastal outlines,
and main roads. For the US, only Interstates are labelled on the map,
but the names of other main roads are displayed if the map cursor is
"panned"moved using the arrow keysover the road, whereupon the road
name is displayed at bottom left. This map is useful only for the most
rudimentary kind of navigation, primarily city-to-city.
All remaining types of map data must be uploaded to the GPS (or, more
accurately, to the SD memory card, which is where such maps are
stored). It's far quicker to copy map data, prepared in the Topo USA
program, directly to the SD card using a card reader plugged into an
available USB slot. The alternative is to upload using the GPS unit's
USB-port cable, which is slow as molasses. This is much better suited
for download of tracks, routes, and waypoints to the computer from the
Even so, for large map files, this can be a slow process, but this
limitation is largely inherent to the type of storage: writing to SD
cards is not especially fast. However, they are cheap, and they have a
conveniently small form factor. I moved about 900 KB of map data to
the card using the appropriate screen in Topo USA. It's also possible,
and maybe a bit faster, to use the Windows "drag and drop" method of
file transfer. As it was, the process took over an hour. However, this
transfer gave me all the USGS quads for the Catskills, as well as the
DeLorme Street and Topographic map, an enormous amount of map data.
Clearly, though, if I'm going to have maps and imagery for several
such extensive areas, it's going to be most convenient to purchase a
number of high-capacity SD cards (the unit will handle up to 2 GB),
and swap these in and out as my travels dictate. Such cards are now cheap.
The Topo USA software package offers two types of map that may be
uploaded. These are regional routable maps (part of DeLorme's Street
Atlas USA dataset, designed primarily for automobile navigation) and
DeLorme Street & Topographic, a high-resolution contoured map,
suitable for serious navigation. The remaining three supported types
of map data are USGS 7.5-minute quads, DOQQ (USGS Digital Orthoimagery
Quarter Quadrangles) aerial imagery, and satellite imagery ("Sat 10
data" i.e. with 10 m, 33 ft resolution). These last three types are
available for a fee, and also require Topo USA for purchase and
preparation. While a certificate for $100-worth of downloads is
supplied with the PN-20, after this has been used up such map imagery
must be purchased. I was pleased to find that my existing data
purchases from DeLorme, collections on CD of USGS 7.5-minute quads by
state, may be easily uploaded to the PN-20.
I'm not aware of any other handheld GPS that currently has the ability
to show USGS maps, let alone aerial and satellite imagery. I find this
an exciting development, in part because I usually use USGS sheets for
backcountry navigation, and it's handy to have the same map on the GPS
as I have in my hand! Most GPS units that display maps provide rather
basic offerings, at additional cost. Whether I will find the aerial
and satellite imagery useful for navigation is a question that I'll be
examining over the course of the test, but it is (at the very least) a
nifty and intriguing feature. I'll unquestionably find plenty of use
the USGS quads (and the DeLorme Street and Topographic maps).
Various information fields may be displayed on the map page, according
to the type of navigation that's being done. What's displayed may be
chosen by the user. I'll discuss this aspect, and my experiences with
uploading and using all types of maps, in the Field and Long Term
reports. Based on my preliminary experience, I do have some minor
concerns with the speed at which the screen is initially drawn
(especially with high-resolution raster maps such as USGS). The speed
at which it is redrawn when "panning" across a map is not especially
fast either. Panning is not an especially crucial operation, but there
are occasions (such as when creating a waypoint at a new location on
the fly on the GPS screen) when the slow redraw speed may prove
awkward. I'll be reporting more on this also.
The map's orientation can be altered using the menu key. So far, I
have generally selected "North up," much as I would use a paper map.
Other options are "Heading up," with the top of the map oriented in
the direction of the current bearing, and "Course up," used when
navigating a route, with the finish point always at the top of the
screen. One other tool of interest, accessible through the Menu key,
is the "Measure tool." This may be used to measure distances and areas
on the GPS.
I have one significant area of concern, connected in part with the Map
page. The direction of travel is indicated, as with most GPS units, by
an arrow-like pointer displayed on the map. The PN-20 determines
direction solely from GPS information. There is no built-in electronic
compass, unlike the majority of GPS units I have used. This means that
when I'm stationary, examining the map, if I turn to face a feature in
the landscape, the pointer will not move, as my change in orientation
can't be calculated from the received GPS satellite data. If I walk a
short distance in the direction of the landcsape object in which I'm
interested, the GPS pointer reorients correctly.
This also means that if the GPS has been carried in a pocket (at
least, when using my favored "North up" setting) the direction of
travel indicator will not be correctly aligned with the landscape I'm
moving through. It's certainly true that I can easily work around this
limitation with a compass, which I'll be using in any case, but if
(for example) I'm trying to identify a landscape feature just for fun,
this lack of response is a nuisance. Still, electronic compass cards
do have their own limitations, I've found. They need to be calibrated
regularly, for one thing! Even so, the combination of bearing
information from both the GPS satellite signals and the compass do
generally make establishing orientation much easier. I'm a little
surprised that this feature is not present in what's otherwise a unit
of exceptional sophistication.
Other important menu items control which uploaded maps display, and in
what order. These functions are found under "Map setup": the "Data
Layering" and "Data management" tools. Suffice it to say for now that
these are critical to the way that uploaded maps display.
This shows a graphic resembling a traditional compass. How this works
depends on whether I'm tracking (keeping record of my trip) or
navigating (which DeLorme defines as following a previously programmed
route). The same caveat I mentioned in the previous two paragraphs
Trip info page
This is a fully customizable page, whose data fields can easily be
altered to suit whatever activity I'm engaged in. For example, on my
ski trips, I was curious to know my maximum speed, a statistic that
I've never measured. Therefore, I set the GPS (with the Menu button)
to display those settings. I was rather surprised to see just how fast
I was going on some of the downhills, though slightly disheartened at
the fairly low average speed. Clearly I'll never be a cross-country
For hiking and backpacking, I'm able to set sunset/sunrise (and
moonset/moonrise), useful for obvious reasons, especially for
backpacks. The same screen can simultaneously show position (UTM/UPS
or latitude/longitude), elevation, maximum elevation etc., etc. I've
already used this page a lot. Resetting the data is easily
accomplished through the Menu button, and it's possible to reset some
fields without resetting them all.
This may if enabled in Setup) be reached by cycling through the pages
using the Page button, but it can most quickly be reached via the Find
button. There are a variety of categories of information, and two find
options: "Find Near Map Center" and "Find By Name." The first orders
the list according to distance from the position indicated by the GPS.
Available via Find are waypoints, points of interest, natural
features, addresses, coordinates, cities, and streets/trails. This is
a powerful tool. It's enabled by the type of base map loaded into the
unit. Not all the listed categories are available for all basemaps.
Options (as in most pages) are reached via the Menu button.
As with the Find page, this can be reached by "leafing through" using
the Page button, but is most quickly available via the Make Waypoint
button. A wide selection of waypoint symbols is available, and the
waypoint can be labelled and commented (using the "virtual keyboard"
which is accessible when the cursor is in certain fields). I have
created a variety of waypoints, and have found the procedure
straightforward and the results accurate. A rather nice feature is the
"Average Waypoint" on-screen button which takes a succession of
position fixes at intervals of about one second for additional
accuracy. Another on-screen button creates a route to a given waypoint
that can then be followed in the Map or Compass pages. Waypoints can
be viewed using "Find Near Map Center" and "Find By Name." They can
also be selectively deleted.
This may be reached via the Setup key, or (if enabled in setup) by
moving through pages via the Page key. I have not yet used this
extensively, and will comment more in my future reports.
I have used this page frequently, and find it very straightforward. It
is reached in the same manner as the Routes page. Generally, before
creating a track, I use the Menu button to set the option that alters
the recording interval settings. There are two types of interval, time
and distance. I generally use time. Also programmable is the recording
interval. The default is rather short (two feet or two seconds, as I
recall), which may be useful for making a highly detailed map but
seems overkill for recording the average trip. Also, since the track
is limited to 10,000 points (position readings) it means that with
such a low setting the track log (remaining capacity is shown by a
percentage progression bar) will fill faster. With a two-second
interval, the track log would fill in about 5.5 hours. By using a
longer interval, tracking may be continued for a full day, or even
several days, depending on the setting selected. Once a track is
completed it may be saved (up to ten tracks may be stored on the
machine) or discarded. If it is saved, the distance of the track is
briefly displayed. Using the Follow (virtual) button converts the
track to a route, which means that it can then be renavigated using
the Route page. Saved tracks may be edited (for color etc.), hidden,
viewed, converted to routes later, or discarded.
Tracks taken while the GPS has only a 2-D fix display in yellow on the
screen. Tracks taken with a superior 3-D fix display in green. Any
hiatus in GPS reception is indicated in red. So far, I have seen all
green, no red!
This gives the moon's phase, moonrise/moonset, sunrise/sunset and the
position of the sun and moon in relation to a compass. Not a major
page, but a very handy one!
This provides tide information, both at the time to which the GPS is
set and at a future or past time. It does so for a number of tide
stations, sorted by proximity to the GPS. As I kayak both on the
Hudson River (which is tidal) and at sea, this is a feature I like
very much indeed. I have not yet verified its accuracy, and will do so
(both in practice and with a set of tide tables).
Device Setup page
This last page is key to correct operation of the GPS. From here, the
system may be modified, by disabling the GPS, setting it to power
saving mode, or using it in the default mode. WAAS may be turned off
and on (since it consumes some additional power to have WAAS enabled,
it's a good idea to disable it in an area where WAAS corrections can't
be received). Battery type is also set from here. Display, interface,
sound, page order, time and units are all controlled from this page.
The Units sub-page bears special mention, as this is used to set
coordinate type (latitude/longitude in various forms or UTM/UPS), the
datum, whether the bearings shown are true or magnetic, whether ground
measure is imperial, metric or nautical, etc. The range of available
datums is impressive, although I did find the list scrolled jerkily
with the up and down button. In changing from WGS84 to NAD27 (ConUS) I
managed to miss, twice.
I've attempted to summarize the operation of the GPS in this section,
but it must be understood that without (in effect) writing my own
manual, with a tool so rich in features it's impossible to do more
than just outline the wealth of available options. My main focus in
the coming four months will be on how well they work.
GPS power use
I've found the strong backlighting of the GPS is sufficient to make
the GPS easily read even in bright sunshine, but at higher brightness
settings it depletes batteries quickly. The extent of battery use can,
to some extent, be controlled. Probably the most effective method of
doing so is to set the unit to "Power Saver" mode in the System screen
of the Device Setup page. This sets the backlight to 10 percent
intensity and sets the backlight time (the duration that the backlight
is brightly on after a button press) to 15 seconds, the minimum period
that may be specified. It does leave WAAS on, and as previously noted,
this creates a small power drain, so this too may be turned off. If a
trail is being created, setting the time (or distance) interval to a
larger value may also cut down on power drain, although this will also
reduce the accuracy of the trail, so this is a trade-off that needs
I have found that the lithium-ion rechargeable batteries are good for
about one day of hiking, using a moderate backlight setting. I intend
to experiment to find the best setting for longer (e.g. multi-day)
trips. Of course, the easiest way to save power is to turn the GPS off
and to take only occasional readings, which is my usual pattern of
use. However, it is interesting and enjoyable to create a track during
a hike and export it to the mapping program.
The GPS can be powered directly via the USB port (clearly, an option
that useful in the field only if a small laptop is also carried). It
will accept standard alkaline, lithium and NiMH cells, or the
rechargeable lithium-ion battery pack that DeLorme cells as part of
its Travel and Deluxe bundles. Whatever cell type is chosen, it needs
to be specified in the "System" screen in order that the power meter
to correctly estimate the rate of depletion.
My preference, for economy and performance, is the rechargeable
lithium-ion battery pack. This is good, according to DeLorme, for
between 300 and 500 uses (presumably complete charging cycles). It
does, of course, entail a higher initial cost but to me this is a
sensible choice for both economic and environmental reasons. (Even
taking the minimum figure of 300 charges, one lithium-ion battery
likely replaces 600 AA alkaline cells.) Recharging time for a
completely depleted pack, using the AC adapter, seems to be
approximately five hours, on average. Charging is complete when the
yellow light on the charger goes out and is replaced by a green light.
The pack may also be charged via the USB port of a computer, or in the
GPS when correct to a USB port (rather like an IPod). I have not, as
yet, compared the useful life of the various battery types in the
field. I will try to give an idea of battery life during the balance
of the test. Since there are so many variables, this will be, at best,
a rough figure.
The manual suggests that batteries should be removed from the unit
when it is in storage. To quote"Because the Earthmate GPS PN-20 has a
real-time clock which requires power even when the device is powered
off, your batteries are constantly in use. If you use your Earthmate
GPS PN-20 sporadically (e.g., more than a month between uses), it is
suggested that you remove the batteries for long-term storage and then
reinsert them when you want to use the device."
Preliminary field experience
While preparing the initial report, I used the PN-20 in a variety of
settings, so I could familiarize myself with its operation. This
included two cross-country skiing excursions. One of these was
backcountry, in woods, fields and hills within a few miles of my house
in the Catskills in New York State. The other ski trip (probably the
last of the season for this area) was in the vicinity of the Mohonk
Mountain House in the Shawangunks, on groomed carriageways. I've also
used it while snowshoe bushwhacking Panther Mountain in the Catskills.
On all of these occasions, the temperatures were quite mild, generally
Elevations ranged to 3720 ft (1134 m). I compared elevation readings
with USGS quads on the second and third trips. The high point on my
ski trip is shown by the USGS topo for the area as within the 1260 ft
(388 m) contour. The maximum elevation shown by the GPS was 1217 ft
(371 m), a reasonable agreement. On the Panther Mountain excursion,
the elevation at the summit was read as 3712 ft (1131 m), taken using
the waypoint averaging feature, and this was an excellent match to the
known highest contorur of 3720 ft (1134 m). There's no USGS benchmark
for that location, unfortunately.
On each of these trips, I logged a track, which I saved. My GPS was
generally stored in a pocket, or in the top of my daypack, with no
special care as to how the unit was positioned. The tracks appear to
have no gaps: the GPS was able to maintain a location fix throughout.
I also saved several waypoints, and found the procedure to create and
label them very straightforward.
So far, the PN-20 seems to work equally well held vertically or
horizontally. If there is a bias for one orientation over another I
have yet to notice it. Most previous GPS units I have used work
optimally only in one orientation, either vertically or horizontally,
depending on the antenna type within the unit. I am very impressed by
the PN-20's ability to pull in satellites in just about any position.
It seems that antenna technology must have improved a lot recently, to
judge by this! I did not have to to resort to rotating the GPS in the
direction of a cluster of satellites, or holding it overhead so my
body doesn't block reception, commonplace manoeuvres for most users of
older GPS models.
In the months to come I will be using the GPS in a diverse range of
settings, from deep backwoods to open water (I kayak, both sea and
inland waters). I don't want to dwell on these preliminary experiences
too much, as I'll be assessing the PN-20 carefully over time. These
are simply some initial observations, and are subject to revision
according to my field experiences.
I did check the DeLorme website for any updates to the firmware for
the GPS, and downloaded the current version, about 14 MB. When I ran
it, the update software reported that I indeed have the current
version loaded. This attempted firmware upgrade went smoothly
otherwise, and based on this experience I wouldn't anticipate problems
with future upgrades.
Topo USA Version 6.0
The accompanying software is available optimized for use with the
PN-20 GPS (it opens with a hint screen stating that this is the PN-20
edition of version 6.0). It is absolutely essential for uploading maps
to the GPS and downloading data from the GPS to maps. It contains the
Internet tools for the purchase of additional map imagery, and has a
host of powerful functions. The interface will be reasonably familiar
to users of some DeLorme software. This is a relatively powerful and
complex program, not a simple utility.
It does have abundant onboard help. Not only are there many hints
associated with actions (these can be turned off if they become
annoying) but the help button, in addition to giving access to a
standard Windows-style help system, also brings up an extensive manual
in PDF format.
The program comes on two disks, one standard CD and the other, with
the program data, on DVD. These are housed on a single spindle in a
plastic case. After some teething pains due to both a defective
program disk and an "iffy" data disk, I was finally (once a
replacement program disk arrived) able to install. This proved quite
straightforward. I had to call customer service for problems with the
data disk as well. They had a workaround, and sent me a replacement
for that also. The computer must be running Windows XP or 2000 with
Service Pack 3 installed, 256 MB RAM is recommended (I have 1 GB), 700
MB of hard drive space must be available, along with a 3-D capable
video card with 32 MB of VRAM. Previous versions of the software may
be retained. The Earthmate Image Tagger program (for linking photos
taken on a trip with the locations recorded by the GPS by reading the
time tags on the images) was also installed.
A screenshot of a typical screen follows:
The program started, and opened a spectacular map of Mt. Washington,
in the White Mountains of New Hampshire. While I love Mt. Washington,
I was more interested in my immediate environs. I went to the tabs
along the bottom of the map screen (visible in the image above) and
selected "Find," the second from left. Using the "QuickSearch" form
(there's an Advanced version that's much more powerful), I typed in
"Olivebridge, NY." Above is the screen that opened, after I divided
the view window. The left hand pane (which can be fully expanded, or
completely closed) is a view of my typed location as shown on the
appropriate USGS 7.5-minute quad. The right hand pane is Topo USA's
view of the identical area. Note that, using the pull-down menu at top
left, I could also have selected other types of available map imagery,
satellite or aerial, for example, assuming I had them available for
the area in question (I do).
At bottom right is a small map of the region, with a rectangle showing
the section of map I'm viewing in the context of the surrounding area.
If I want to examine an adjacent section of either map pane, I move
the cursor to the edge of one of the frames, whereupon it turns into a
hand icon, and I hold the left mouse button down and slide the map in
the appropriate direction. I am also able to scroll the map using the
directional arrow pad on the top of the right-hand vertical tool bar
(see screenshots). Above that (directly under the Topo USA 6.0 logo)
are the controls for scale, so I can zoom in or out on the map region.
The increments range from 1 to 17, with intermediate zoom levels (e.g
11.4) available. 1 is, in essence, a view of the world. At 16 or 17,
details are extremely magnified. Aerial data is borderline-useful at
One interesting feature of the software is the ability to examine a
map view in 3-D. The controls for this feature are also on one of the
tabs along the bottom (although a 3-D view can also be opened by
simply changing the small box next to the map type pull-down menu to
3-D). This creates a "bird's eye" view; the vantage etc. can be
controlled from the 3-D tab.
The tabs at bottom (left to right, refer to image) allow access to map
files; find (already mentioned); printing; provide a set of draw tools
for various purposes such as creating exportable waypoints; control a
GPS attached to the computer (this more for mobile laptop users);
create a route for export to a GPS; create an elevation profile for a
map feature or a draw feature; provide the 3-D controls; provide info
on any map feature the cursor is on; operate NetLink, allowing the
purchase of map data and the updating of the software; and Handheld
This last tab (part of the functionality of this tab may also be
reached by a button at the top of the screen) is central to use of the
program with a GPS. This permits the uploading of various kinds of
data, including map imagery, and the download of tracks, waypoints and
routes. I have found it easy and fairly intuitive to operate. Below is
a screenshot of a map with a downloaded track, from that first
cross-country skiing trip.
Screen shot 2
The track is shown in red, with one waypoint where I saw the fisher
(at bottom right). I didn't turn the GPS on until I was some distance
from home, so the outbound track is slightly incomplete. This is a
good demonstration of the high quality of track that may be generated
with the PN-20. The map on which the track is displayed here is a USGS
quad. Using the "Profile" tab I am able to click on the track, and
learn that (among other things, I skiied 6.35 mi (10.2 km) with an
elevation gain of 555 ft (169 m). Not exactly an epic adventure, but
good to know the trip statistics!
The quality of Topo USA's basemap is very good indeed. I will be using
these for navigation as well as my usual USGS paper quads during the
test, for comparison. The contour interval changes as the map is
zoomed in, down to a resolution of 20 ft (6 m), equivalent to the
usual USGS quad interval. The maps show an extensive range of
features, including woodland, roads, rivers, etc. Using the "Info" tab
I can click on any given item and find out what it is. In addition, in
the "Options" screen (reached from a button at the top of the screen,
I can selectively hide particular features. Shading may be added to
both the Topo and the USGS maps to better demonstrate relief, but I
prefer to work without it, relying on reading the contours.
This is the merest summary of the workings of a sophisticated and
ingenious program, which I will be reporting on further as the test
proceeds. I am pleased with the ease at which data can be exchanged
with the GPS, and maps uploaded. The installation issues seem to have
been the result of a bad set of disks, rather than any defect in the
Aerial Data Packets
The procedure for purchasing these, from within Topo USA 6.0, using
the NetLink tab, is fairly straightforward. I pressed the "Datasets"
button with the map zoom set to 11 (this is the minimum for this
process), selected about US $30 worth of imagery for my local area
(satellite, aerial and USGS come bundled together), selected "add to
list," then used DeLorme's purchase feature. The data is not instantly
available, but I received an e-mail within five minutes (there's also
notification on the NetLink tab) that my maps were ready for
collection. The total file size for download was about 25 MB. I have a
high-speed Internet connection, and that would seem to be well-nigh
essential for downloading map imagery, given the file size of any
significant amount of information. Download was extremely swift, and
it seems DeLorme's servers are fast. It is possible to purchase ADPs
in CD form and thereby avoid downloading, although not with the free
certificate I was provided.
Once downloaded, I viewed the maps in the left-hand pane of Topo USA
(I found that for some reason I had to restart the program first),
confirmed that they were what I had ordered, and used the tools on the
"Handheld Export" tab to save a map package of the aerial and
satellite data (only, as I already had uploaded the USGS quads for my
region). Processed for upload, the total was 47 MB, and as this was a
fairly small chunk of data (though also a small chunk of terrain) I
uploaded these to the PN-20 via the USB cable, which slots easily into
the back of the unit. In the interim, I went on with this report.
Transfer to the GPS from Topo USA via the USB cable is rather slow,
and in future I will probably copy the files to the SD card directly.
I used the "Options" tool to set the zoom range for this data to the
maximum (N.B. zoom range for uploaded maps is controllable).
Having uploaded these to the GPS, I inspected them. The imagery was
interesting, but the ability to zoom in was restricted by resolution
issues. At the 0.5 mi (0.8 km) scale I had an interesting bird's eye
view with the satellite imagery, at 0.25 mi (0.4 km) the quality was
still borderline acceptable, but at 640 ft, 195 m (the next step)
blurring was a nuisance. This is probably the highest zoom level
that's likely to be of any conceivable field use, and indeed an
"overzoomed" message shows at bottom left of the screen at this from
the 0.25 (0.4 km) mile resolution on in.
If the DOQQ data layer is also enabled (using the GPS map setup, the
layering options), when the satellite map data overzooms, the aerial
map data displays instead, and this is of a substantially better
resolution. The presentation, on the small TFT screen, is surprisingly
adequate. While the ability to display this data is extremely
exciting, I will be curious to see whether the satellite or aerial
data is useful for field navigation. I do think it likely that the
aerial data, at the least, may be useful for spotting potential
camping areas and perhaps for avoiding heavily overgrown or rough
terrain. Panning ahead of the location is a bit like getting a preview
of the country ahead, although not enough to spoil the pleasure. I
like the concept.
My initial impression of the Earthmate GPS PN-20 has been very
favorable. While I have a few minor reservations above about the way
certain features have been implemented (such as the lack of an
internal compass and its effect on the ability to display accurate
headings) these really don't detract significantly from the
extraordinarily rich features of the device, not to mention the
quality of the accompanying software. My hope is that these will prove
to be minor matters, and I'll learn to work around them.
In circumstances in which I have been able to check accuracy, the
PN-20 seems to be extremely accurate (certainly within the specified
tolerances at the time the reading is taken) for position, andbased
on my past use of altimetersit is at least as accurate as a
calibrated wrist altimeter for elevation readings. It's also capable
of maintaining a good fix on location over a substantial period,
making tracking a breeze.
The speed with which the TFT display for the unit redraws sometimes
seems a little slow. Even when navigating lists of options, there
seems to be a certain lack of responsiveness. This is not a major
issue. A little more troublesome is the slow initial display of maps,
especially USGS 7.5-minute sheets, and aerial and satellite data (Topo
USA maps generally display much faster). While this is of some
concern, it remains to be seen if in practice, over time, this proves
to be an inconvenience. Still, the very fact that the PN-20 is capable
of loading and displaying such complex imagery is a massive leap in
handheld GPS technology, one for which I have been waiting for a long
time. It wouldn't be an exaggeration to say that I see this as the
harbinger of a new generation of GPS units with greatly enhanced
Please check back in two month's time for my field report, and two
months after that for my long term report. I sincerely thank DeLorme
and Backpackgeartest for the exciting opportunity to test this GPS.
This report was created with the BackpackGearTest.org Report Writer
Version 1. Copyright 2007. All rights reserved.
- Next post in topic >>