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In Search Of The Perfect Fieldwork GPS



So I’ve been following GPS Tracklog’s coverage of the Consumer Electronics Show last week in Las Vegas, and been underwhelmed by the handheld GPS announcements:

  • Magellan announced nothing new.
  • deLorme announced their PN-60 model; while it adds an interface with a Spot Satellite Communicator, the GPS capabilities are essentially the same as with the earlier PN-20/30/40 models.
  • And Garmin announced the Oregon 450 and 450T, which join the Oregon 200, 300, 400, 400T, 400i, 400c, 550, 550T. They all pretty much offer the same GPS functionality with minor option tweaks (electronic compass, barometer, camera, built-in map sets).

At the same time, I keep getting asked by field professionals what the best handheld GPS is for serious field work. I have to tell them that there isn’t a single model currently available that does everything I’d like to see in such a unit, so they have to make some compromises. While professional-grade units are available from Trimble and Ashtech (formerly Magellan Pro), they tend to be much more expensive than consumer units, less rugged, have shorter battery lives, and run Windows Mobile (aack). And while they’re good at data recording, they’re nowhere near as good as standard consumer GPS models when it comes to navigation and map display.

There must be tens of thousands of field workers out there who would be a ready market for a reasonably-priced GPS that met their needs, like geologists, biologists, archaeologists, etc.. I’ve put together a list of what I’d like to see in such a unit; feel free to add your own suggestions in the comments. And it’s not like the requirements are all that difficult to meet; in one form or another, you can find most of the following features already present in at least one commercially-available consumer-grade model.

  1. High-sensitivity, high-speed, high-accuracy GPS chipset.
  2. Galileo/GLONASS support for higher accuracy.
  3. Readout of the Dilution Of Precision, plus a graph that shows you the DOP for the rest of the day so that you can choose times of lowest DOP to get the highest accuracy with your GPS measurements.
  4. A high-gain, omni-directional antenna. Many units these days come with just a small ceramic patch antenna, and tend to have less signal gain and be more orientation-sensitive than the “stubby” quad-helix antennas found on models like the Garmin 60CSx and the Garmin Colorado series.
  5. A decent-sized screen that’s easily visible in direct sunlight. 2.6” diagonal is a bare minimum, 3” is even better. Many recent models have higher resolutions and greater color depth than older models, but sacrifice daylight visibility as a result. I’d rather have a unit with fewer colors and lower resolution that you could use in daylight than a sexy high-tech screen where you can’t see anything on it unless you hold it in the shade with the backlight on.
  6. An easy interface for adding text. If it doesn’t detract from screen visibility, a touch screen is fine, but a slide-out keyboard would work as well.
  7. Buttons with programmable functions. One of the big problems with touch screens is that you sometimes have to dive multiple menu levels into the interface to access a needed function; the ability to call up such a function with a single button push would make life a lot easier.
  8. Decent battery life, at least 15-20 hours.
  9. Rugged and waterproof.
  10. More waypoints, tracks and trackpoints. Some models currently sold allow only 1000 waypoints, and 10,000 trackpoints, to be saved. I’ve never had to have more than several hundred waypoints myself, but I’ve hit my unit’s limit of 20 tracks and 10,000 waypoints many times.
  11. The ability to add your own GIS map data, like point/line/area shapefiles, for display on the unit, preferably with at least some attribute data.
  12. Loadable vector maps, from the manufacturer and/or custom maps created by the user or others.
  13. Raster imagery like topographic maps or aerial imagery, both standard mapsets (like USGS topos) and your own custom imagery.
  14. A tri-axial electronic compass that works regardless of how you hold the GPS.
  15. If you have a tri-axial compass, you have the electronics necessary to determine the angle of orientation of the GPS with respect to the ground. This would be useful for geologists (dip and strike), archaeologists (site maps), geomorphologists (ground slopes), botanists (calculations of tree height using angle), and presumably others as well.
  16. Some means for recording additional data associated with a waypoint. Standard waypoints are limited to about 30 characters in the note field, and expanding that to a larger size to add more info would be helpful; another option would be audio recording capability that’s linked to the waypoing.
  17. A built-in camera with both automatic geotagging, and automatic tagging of the direction the picture was taken in. 5-megapixel minimum, with autofocus and a macro mode for closeups.
  18. Bluetooth NMEA serial output so you can use it with a laptop or PDA.

It’s unlikely that any of the current manufacturers of consumer-grade GPS models will someday decide to create a “prosumer” model with a reasonable subset of the features above. But a guy can dream ….

… and he can also try to put together an affordable field-ready PC with GPS and GIS functionality. More on that soon.





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12 Responses to “In Search Of The Perfect Fieldwork GPS”


  1. 1 Terry

    While we’re at it, can I get 3 Ferraris and a river of beer?

  2. 2 ChrisMcGinty

    Curious what you think a reasonable price (or what would you be willing to pay) for a unit with all of these features might be?

  3. 3 Tom

    I actually think that something like this might be lucrative for the GPS makers out there. The old consumer GPS market is rapidly losing ground to the cellular telephone. Who wants a separate GPS when your iPhone has one already built in?

    If Magellan, Garmin, and the others want to stay in business, they’re going to have to come up with something new.

  4. 4 Leszek Pawlowicz

    Well, the Garmin model that comes closest to meeting all these requirements is the Garmin 550, which sells for $429 at Amazon. I would guess that hardware modifications would result in the largest cost increase, while software modifications would be relatively cheap. Here’s what you would need to do to make the Garmin 550 meet my requirements:

    1. Nothing – already has a high-sensitivity chipset
    2. Has a ceramic patch antenna, but the very similar Colorado series had a quad-helix antenna, so adding it shouldn’t require any major engineering.
    3. Has a 3″ screen, and successive generations of Oregons have had better sunlight visibility, so this shouldn’t add much more to the cost.
    4. Nothing – has a touch screen.
    5. Minimal hardware cost, plus software.
    6. Nothing – already has this kind of battery life.
    7. Nothing – already waterproof and reasonably rugged.
    8. Memory is dirt cheap, so the only significant cost impact would be in modifying the software.
    9. Given all the freeware programs that can do this now, it shouldn’t be that expensive.
    10. Nothing – Garmin has vector maps, and there are free/cheap programs that let you create your own maps already available.
    11. Nothing – the Oregon lets you upload your own raster map imagery. Could use better software to do this, plus the ability to upload more maps and select between them.
    12. Nothing – already has this.
    13. The software required for 12 automatically extracts out the angle, so this is a minor software upgrade.
    14. Audio recording would add something, but text notes would be a simple software upgrade.
    15. Probably the most expensive upgrade, but given the prevalence of standard stand-alone digital cameras, I’d be willing to sacrifice this upgrade to pay for the other ones.
    16. The Oregon already has the capability to exchange waypoints wirelessly with other Oregon units, though I don’t think it’s Bluetooth. Swap out the current wireless for Bluetooth, and you’re there.

    Drop the camera to save money, and I’d guess you could sell such a model for somewhere in the range of $500. Expensive, but professionals might be more likely to pay that kind of money for a tool useful for work.

  5. 5 Silas Toms

    I’ve begun creating something like this by integrating a Garmin 20x receiver and Dell Mini netbook. The advantage is having a full hard drive and screen, plus WiFi and a decent battery life. The downside is configuring a Python module for reading the Garmin proprietary output. Anyone have any ideas on that front? I’ve found PyGarmin and will try to update it for use with the 20x. Has anyone done this yet?

  6. 6 Leszek Pawlowicz

    I guess I could add that the Magellan Triton 2000 has all the hardware needed except for the digital camera (it’s only 2.2 MP) and the omnidirectional antenna. It was built based on the Magellan Pro Mobile Mapper 6 platform, which runs applications that do most of what’s needed. They ran into huge problems by replacing the standard interface with an incredibly buggy “consumer-grade” one. If they went back to the professional-grade version, and added a better antenna, they’d pretty much be there. The model currently sells for $400 at Amazon. The Triton 1500 with no camera and compass but otherwise identical to the 2000, sells for $237; add the compass and a better antenna to the 1500, skip the camera, fix the software, and I think it could go for less than $400.

  7. 7 Wolfgang

    Hi!
    The biggest problem we have with consumer GPS units here in Germany is with projections. A unit (the GIS software) has to be able to convert the GPS coordinate to several national projections with an accuracy of at least 1 meter. In my optinion professional fieldworkers can do their work only with professional software, i.e. ArcPad, Digiterra Explorer or something similar. An then we are committed to Win Mobile units such as MobileMapper 6. In fact in my opinion the MM6 is the most suitable model for professional, not too expensive field work. The accuracy is amazing – we’ve tested it in forests with and without postprocessing. The Trimble and Garmin units in this price segment are not a quarter as good.

  8. 8 Mats Elfström

    Hi!
    I absolutely agree with all the above, and as all the components are existing technology it would only be a matter of putting it together in a rugged shell. I definitely think there is a ‘prosumer’ market for this product, seeing what some high end units cost already.
    I have serious doubts about the camera, though. I think that would add bulk to the unit and be susceptible to dirt and damage.
    Geotagging if images is a great thing, but it would be better to build this into real cameras, perhaps with a NMEA bluetooth receiver.

  9. 9 Getiem

    What is also nescessary is a GPS that doesn’t interpolate between waypoints. In a heavy building area they tend too lose sight on satellites. When going around a corner some GPS calculate their position from the last known point and guess where you are.. Very smart, but unwantable..: Walking around a square building, you get a track with rounded corners

  10. 10 Rich

    I agree whole heartedly with the general needs of the community. Unfortunately, the scientific world is often torn by the complexity of the needs of their projects. In some cases, cm level accuracy for surveying is needed and in other times several meter accuracy is “good enough”. In all cases, ease of use and reliability turns out to be the most critical when collecting data. Like another reader, we have been Magellan’s MobileMapper for this. Unfortunately, Magellan (or Thales or now Ashtech) have to develop a good hardware solution and stick to it. I have an old Ashtech (SCA-12; now 13 years old) which works great even though it is no longer supported, but the 3 year old MobileMapper5 we invested in is now close to a paperweight due to end of life and lack of software support.

  11. 11 tlove

    using a Nokia N810 with Maemo Mapper really opened my eyes to what is feasible today in the market and what a prosumer field GPS would look like. this is is very feasible; Arm processor, mobile linux distribution like Maemo, 4.5″ to 5″ screen at WVGA, lots of NIMH batteries (lithium is expensive), transflective screen or pixelqi screen, reasonably rugged, good GPS chip and antenna, all for less than 800$ more likely down to around 500$. this would not be precision gps but it would allow for a wide variety of GIS in the field applications. check out the GPS apps for UDIG and the new one for QGIS, ArcPad is great but its days are numbered as are the units garmin keeps pushing out. the cost, size, and power consumption on on all of these parts has been dropping so rapidly i will be surprised if we dont see some solutions along these lines in 2010.

  12. 12 Justin

    as always, very useful information that i will pass along to my fellow members at Land Surveyors United. we always appreciate the valuable information on your blog. Thanks!

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