GPS recommendations, anyone?

I’m going to be buying a GPS receiver in the next few months, and am fishing for comments/recommendations/etc.

I’ll be using it for field work (which entails hiking off the beaten path for the most part), and I’ll need to have 2-3 m horizontal resolution (sub-meter would be overkill). I’ll have about $5,000 max. that I can spend.



This GPS receiver… should it attach to a PC Laptop, PDA, or Mac Laptop or simply be a stand alone unit?

Are you driving off the beaten path, or literally hiking there as your post implies? How far off beaten path, and what sort of battery life are you going to need?

What geographic area are you needing it in?

From what I’ve seen, you can get by way under $1000 with a Palm OS PDA (cost depending on which model you go for) and GeoDiscovery™ Geode™ GPS Module (Price: $289.00 U.S) which claims.

Which may suit what you’re looking for, from the desciption of your needs posted so far. I’ve never used one, but it’s on my “investigate and buy” list.



I suppose a stand-alone unit is fine, as long as I can import the data into a GIS database later. I’ll literally be hiking - we’re going to be locating prehistoric quarry sites in several undeveloped areas in the northeastern US (although for the future it would be handy to take the GPS elsewhere in the US, too). A regular field day for me usually entails about 8 hours of work away from whatever vehicle I’m driving, so the battery life ought to be at least 12 hours at a clip.

As you can probably tell, this is all new to me, so if you think I’d be better served by downloading info into a laptop on the fly, etc. please tell me. I’m all ears. :slight_smile:


I’m not familiar with GIS databases (Geoscience Information System?), so I’m not a lot of help there. As an all around computer geek, I don’t see any reason you can’t download readings from a palm or laptop to any other form of computer and get it into the format you need it to end up.

How much is weight a factor? Are you hauling a lot of other equipment, so 7 pounds of laptop would be a big factor, or are you usually carrying a minimal load of other equipment so that carrying a laptop in a backpack would be of little concern?

I am still leaning towards recommending the PDA & add on I recommended earlier, though that may be because I just yesterday purchased a Visor Deluxe by Handspring and am feeling somewhat evangelical about them. (So do feel free to take this with a chunk o salt)

If you do go the PDA route, I strongly recommend a very sturdy case (I was pointed to this one in another thread when I was asking for PDA opinions: Rhinoskin Aluminium Slider) as most PDAs main weak point is their screens.

So, how are you expected to get this information into the GIS Database? (That might help point in a helpful direction for what sort of GPS Receiver is a good bet.)

I’m hoping that someone with actual experience using a GPS system, and maybe even knowing about GIS databasesand how they get GPS information into them stops in soon :wink:

Otherwise, the resident expert may soon be you.


You don’t need a PDA for GPS, but you may want one if money’s not too important, or you already have one.

I’ve got 2 gps receivers, both should be available for about $100. My handheld one is a Magellan 315, and the one for my car is the RandMcNally receiver only (useless without a computer).

Any GPS receiver you get today should provide sub-10-meter accuracy, since selective availability has been shut off. If you’re really really going for accuracy, you need to consider DGPS. Differential GPS recievers use the normal satellites as well as ground based correction stations to provide a very accurate fix. If realtime coordinates are not incredibly important, then you can use post-processing of recorded normal GPS readings to get DGPS accuracy.

Any modern handheld receiver should allow you to up and download waypoints and routes, and record/playback positions. Garmin and Magellan are very good brands. All you have to do is decide how many waypoints and other things you want to be able to store, then find the receiver that meets those qualifications.

My dad has a more expensive receiver that has a slot for map cartridges so he can actually have a moving map display on his receiver. The same can be done with the various PDA gps units (handygps, geode, magellan has one).

Bottom line is that most commercial receivers will probably do just fine for you.

Oh, and check out for some fun.

Thanks, guys!

dublos, as long as data are georeferenced and in one of the common GIS (Geographic Information System) file formats (ArcInfo, MapInfo, etc.), you can import the data as a separate layer in a GIS database (so that you end up with a map that has multiple layers of information that can be displayed on command). Real-time plotting of the info isn’t crucial for me, so if I can stay away from toting a laptop in the field I’ll be happy. A PDA might not be a bad thing to get, considering the other things I could do with it as well.

TheNerd, thanks for the info on specific models - it gives me a good starting point. Maybe once I’m more proficient I’ll start cache hunting, too. :slight_smile:


Ok, what you said just raised all sorts of red flags and set off warning bells.

You will definitely want to do further research into this. Those are very specific file formats, and I do not know if a consumer market GPS receiver which is really just designed for home/navigational use will automatically be able to give you the data in one of the file formats needed for GIS.

You absolutely do not want to spend a penny on this until you’ve researched the entire data path from the GPS receiver to the GIS database. I assume that, worst case, you have a way you could manually enter the coordinates that a GPS receiver gives you into software designed to add it to the GIS database, but I think you and everyone else involved would be happier not to have the additional possibility of human data entry errors getting into the data.

So… do you have any technical resources on the GIS database side who can tell you about software available for the PC or a PDA which can import, lets say a tab delimited file? Are you looking for latitude, longitude, and comments (i.e. what’s at this location that you took the reading for), or are you also needing altitude?



As I understand it, it is possible to take tabled data (as in a tab-delimited text file) and bring it into the GIS. But you’re right - I need to do some more digging, because as I mentioned before, this is a new process for me. Your comments (and TheNerd’s) are giving me some basis from which to consider the possibilities, and I appreciate that.

FWIW, I have some experience working with a GIS-compatible plug-in for Adobe Illustrator that allows you to display geo-referenced data; ArcView is going to be a new beast to tackle. I don’t really need altitude - just lat, long and comments for each site. And I definitely do NOT want to have to manually enter the coordinates for hundreds of individual sites. :wink: