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Best Setup for Mapping in Undeveloped Countries?
Floodimus asks: "My girlfriend lives and works in West Africa and on my next visit she has asked me to help her do some mapping of uncharted villages. I want to make this study really accurate and useful, so I am thinking about using high tech and low tech resources such as GPS and good old fashioned compasses, but I was wondering what the Slashdot crowd would recommend for GPS hardware (does GPS equipment from the US work over there?), field equipment, mapping software etc. I use both PCs and Macs and would like the software to run on the Mac, but it doesn't have to. What's the best, most rugged stuff you've used? Where are some resources that would help me out?"
does GPS equipment from the US work over there?
Ok, a quick explanation of how this stuff works is in order. GPS stands for Global Positioning System. The system consists of 24 or so satellites that provide nearly complete coverage of the globe at any given time. By capturing signals from more than one of these satellites, your receiver can calculate your position based on the last known position of the sats. Thanks to the precision and accuracy of modern electronic hardware, this calculation can be accurate to within 20 meters or less.
More info here
So to answer your question, of course GPS equipment can't be used over there! They use 220V AC and we use 110V AC. Where do you think you're going to find a charger? You need to get yourself a step down transformer, or you'll never be able to charge the equipment! Yeash, what are they teaching you kids these days?
Javascript + Nintendo DSi = DSiCade
And instead of rugged, think small. You can get a small GPS that you can plug into your laptop via USB for under $100US. Should outlast the laptop.
As for mapping software, if you truly want it to be useful, just save off the coordinates and wait until you get Internet access, then integrate with Google Maps using their recently released API and you'll be able to actually look at the villages from above, on your computer.
Actually, this is the perfect time to be doing what you're doing.
does GPS equipment from the US work over there?
No. We made sure to send Africa very very degraded signals. How much does a meter of accuracy matter in a desert or jungle anyway?
pooptruck
I travel in the US with a GPS in my laptop bag (Garmin GPS V), but depending on where you travel in the world, you may want to insure it doesn't violate any local laws. For example in (don't mod me funny) Ex-Soviet Russia it is illegal in most cases to have GPS equipment. You can be thrown in jail and it may not be pleasant.
unless you get the discounted Global -except West Africa- Possitioning System.
http://www.watacrackaz.com
To my knowledge, Trimble makes the best/most rugged GPS units available. They supply the military. They also have specialized equiptment for mapping. Here is the linkage: http://www.trimble.com/
There are also armored/waterproof cases and what not you can get for the more common off-the-shelf units.
As for software and compatability...I'll defer to someone else to post on that.
(does GPS equipment from the US work over there?), field equipment, mapping software etc. I use both PCs and Macs
1) GPS equipment, bought anywhere in the world, works anywhere else in the world, since GPS satellites cover the entire globe
2) All you describe is fine and dandy, but it seems to me that you're forgetting one crucial part of it: power supply. In the Middle of Nowhere, West Africa, you may not be able to find wall outlets everywhere to connect your laptop to everyday. What's more, if you do find power, your laptop might not like it (voltage spikes, bad frequency...).
So my suggestion is that you start designing around your power supply. Solar? Generator? how to conserve power? PDA or laptop? what size battery to you expect to need? etc etc... all that depends on the exact application.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
To use a GPS device in the southern hemisphere, (ie south of the equator) you have to hold it upside down.
My first thought isn't what equipment would be the most fun or powerful, but what equipment will work. How reliable will electricity be in the area you are going to be mapping? Since you describe these areas as uncharted, ,y guess would be "not very," so don't expect that Mac to always be available to you.
Now what are you going to do without that laptop? You're going to need a GPS device that runs for a *long* time on batteries, or you're going to need to bring a crate of batteries where you go. You're also going to need something that allows you to save and tag all this GPS data so that you can decipher it when you do get back to a computer.
Get that figured out, and if you have any money left over, THEN you can start thinking about buying that copy of ArcView.
http://gpsinformation.net/
Hope this helps
He who knows best knows how little he knows. - Thomas Jefferson
If you're looking for something compact, rugged and with a decent screen, the Garmin 60CS would be a good choice. I've had mine for two years and have put it through hell - backcountry hiking, sailing, flying, dousing it in mud, beer and water (it's waterproof.) The screen is small but readable in just about any lighting condition (great in direct sun!)
My only complaint with Garmin is the expense of the maps, but I've yet to see much serious competition as far as hardware goes.
I think that a handheld (Palm) would be more convenient for measurements than a laptop. Handheld and GPS receiver do fit in your pocket and they have less moving parts than a laptop.
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Good generic GPS info plus specific tips for mapping in Africa to be found here: http://www.gpswaypoints.co.za/
Don't invent the field of cartography from scratch. Study it before you leave.
I don't know what "mapping" means in your case. Are you trying to show where each village is or are you trying to create street maps of the major towns? In any case, find out what maps already exist, then go get yourself the best satellite photos you can find, and when you get there, prepare to rent small aircraft for some aerial photography. Trying to map West Africa on foot from scratch with a pocket GPS device would be a fool's errand.
And be VERY CAREFUL. People who make maps are often considered spies by people who carry guns. You'd better be very sure you know what you are doing and have the necessary permission from whoever (official or unofficial) controls the guns in the region you are mapping.
"Those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded."
You should also be careful of the impression you make on local police or military personel. I don't doubt that many of them would be suspicious of an American (since you asked about U.S. equipment) wandering around with electronic devices to map villages or roads.
Never mind that if the military or intelligence agencies really wanted to know where things were, satellite images would be even more accurate than a cheap/rugged GPS. Many West African countries make it illegal to photograph airports, military bases, police stations and the like.
I'm not saying don't do it, just be careful who sees you. No reason to give excuses for an anti-western, self-important jerk with an automatic rifle to harrass you.
latitude, longitude, elevation, time
*Everything* else is interpolated from that info, and if you lose satellites, you lose everything. Even if you stand still, GPS won't tell you where north is; you have to be moving so it can triangulate.
A GPS has some capabilities that overlap with a magnetic compass, and vice versa, but it is extremely risky and potentially hazardous to substitute one for the other.
That being said, I don't know what the OP was planning to do with a compass for mapping villages anyway: a compass doesn't tell you where you are, it only tells you what direction you're facing.
KeS
Bad Panda! No Bamboo for you! In matters of importance ACs will not be responded to. Want to say something critical,OK
I'm sure many others will cover equipment, power charging and such - I'll cover how you should do this. Well, since I taught in a developing country for a few years, this is my suggestion of how...
Developing countries generally have a huge surplus of labor - it's one of their biggest resources. They also, like a lot of the world, tend to have lots of kids who are eager to learn new stuff.
What you need to do is take several GPS receivers with you and hook up with a local teacher who can integrate GPS ideas and geography in with their lessons. The teacher could even make it a special project working with trustable students to map their own village(s).
The key here is to push as much onto the students as possible so they do the work and they learn. You'll help the teacher, help the students and help make more than just maps.
I travel in and out of Africa about once a month on business, hitting about 15 countries on average each year. I can tell you from experience that it is VERY dangerous to be seen using a GPS near Military installations, railroads, shipping, and anything the locals consider of strategic value. This generally means about everything. You should be extremely circumspect when using the GPS. You may have it confiscated, or you may end up in a cell somewhere with arabic graffiti on the walls. Not good. Your best bet is to make sure you contact your local embassy in the country, and ask their communications personnel about local sensitivities to GPS. You could always ask the Regional Security Officer (RSO) also, but be forewarned that they often err on the side of safety, have a poor understanding of much tech, and could very well say not without a moment's hesitatin to avoid having to retrieve you from your cell when you are snagged. Best bet; use it for quick position fixes, then put it away. It is also not safe to display an item that costs more than most locals make in a month of hard labor. Good luck!
73 SK
HOWEVER, many handheld GPS units, especially slightly higher end ones DO come with built in compasses, and can tell you which way is north even when you're in the basement of a building with absolutely no satellite reception and you're not moving. (My Brunton MNS falls under this category)
Bottom line, you should know what you're buying and what features it has before you get it.
On a somewhat related note, having a built-in compass can be extremely useful, as it will tell you how far away and in what direction a mark is even when you're not moving - it will tell you relative to the orientation of the GPS. Many units without a built in compass only tell you in what direction a mark is relative to direction of travel - so this can be very confusing if you're standing still or haven't oriented the unit in the direction of travel. Hope this made at least an inkling of sense.
While GPS works everywhere, the Wide Area Augmentation System (WAAS) is only useful for the Continental US. WAAS units will work elsewere but they will only have the resolution of standard GPS. If you need better than standard C/A code accuracy use Carrier Differential (CDGPS) mapping using two Garmin recievers and a copy of GRINGO (http://www.nottingham.ac.uk/iessg/gringo/).
The Garmin Rhino units w/ integrated FRS Walkie Talkie units are vaery rugged and may be handy for survey. Additionally, to quote the Operation Iraqi Freedom
PEO Soldier Lessons Learned report:
Commercial GPS: As is widely known, many soldiers purchase their own GPS systems rather than use the PLGR. The Rhino was provided to the 82d as part of the rapid fielding initiative. Overall, soldiers were very appreciative of this addition to their MTOE. The Rhino was a vast improvement over the PLGR because of the weight, volume, power consumption and performance - the Rhino consistently acquired satellites faster than the PLGR. However, the soldiers stated they did not use the communications capabilities of the Rhino, at least not extensively, because it was not secure and consumed batteries too quickly in this mode.
If it survives the front lines in Iraq, West Africa should be a cake walk.
A compass, if you know how to actually use one with a map, can tell you a great deal about not only what direction you're headed, but where you are and, more importantly, it can do something that GPS Just Plain Cannot Do, namely, it can tell you where that unknown landmark is, which in Western Africa is an incredibly useful skill. The last thing in the world a foreigner should do is wander into an uncharted village. Best to get an intersection on it from range, record the position, and move on. Now, this doesn't mean that you shouldn't use GPS. In fact, GPS can be used in conjunction with the intersection technique in order to give you your 'known points'. But don't rely on a single piece of equipment to find your way around some petty warlord's backyard.
For most of 2003 and 2004 I was working in rural Madagascar on a reef conservation project (as Diving Manager, Scientist and general tech guy).
We primarily used handheld GPS units (Garmin, Magellan) for mapping the outlines of the reefs. This was accomplished by attching the GPS in a waterproof bag to a float and towing it behind a diver. It was fairly effective, and provided data good enough for GIS work.
We also mapped the roads (read: dirt tracks) and trails in the local area, but the part that seems most approprate to this discussion was mapping the local fishing villages for socio-economic research.
We mapped out the main roads, the major buildings, and all of the houses that we interviewed people at so that we could build up a full profile of the village for input into our GIS work.
For most work, the most basic GPS units were fine (eg. Garmin Etrex, and 7x series - we also used a couple of Magellan and Silva units). Use rechargable NiMh batteries as although they don't last as long as alkalines, you can use a solar recharger to give you an endless supply. (As an aside, only the Garmins were able to run on the crappy local batteries).
As an idea of where we were - the nearest phone line was over 200 miles away, and the only reliable method of communication was satellite phone (radio messages could sometimes get through via several mission relays, but if the weather was off then no chance).
I used a couple of fairly old (P2 233) Toshiba Satellites as my data machines as they could take a beating and keep working (and were free). (Win 98 on both and a dual boot to RH 9 on one)
Hope this helps...
Dan.
Hardware:
3 .pdf
Get a Garmin handheld GPS with a 12v adaptor & download cable, and probably a crate of AA batts.
Stick with consumer stuff. Buying a spare or 3 is cheaper than buying a Trimble survey grade and they all work well enough.
GPS Software:
Download GPStrans &/or GPSbabel.
http://gpstrans.sourceforge.net/
http://www.gpsbabel.org/
You can load the GPS waypoints/track/routes into a mapping format with GRASS GIS's v.in.garmin or gpsbabel+anything.
Mapping software:
Use QGIS. http://qgis.org/
Use GPS plugin.
Data:
Start by downloading SRTM elevation data and VMAP0 digital chart of the world data. Best there will be publicly available for Africa.
Instructions for converting into a usable format here:
http://grass.ibiblio.org/newsletter/GRASSNews_vol
Import and crop with GRASS GIS (r.in.srtm and v.in.ogr modules) and either use with QGIS directly or export into a secondary more popular format for use with other software.
GRASS works well on a Mac. http://grass.ibiblio.org/
GPS interface programs should work on a Mac, GPStrans is command line only so with some hacking and GPSbabel is well maintained so there should be a Mac port by now.
SRTM: http://www2.jpl.nasa.gov/srtm/
VMAP0: http://www.mapability.com/info/vmap0_index.html
~.~
I'm a peripheral visionary.
Since you're talking about charting villages in Ghana, worst case is you'll have a 100 meter uncertainty in their locations, which is probably still much better than you have now. More likely you'd have a 5-10 meter uncertainty, and you'd have a similar uncertainty with nearby landmarks (so if the village is next to the river, they're both uncertain by 10 meters but you can see where the river is.)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Something I've seen missing from the discussion so far is much focus on understanding maps and navigation.
If you don't know how to read and use a map, it'll be much harder to make one that's even remotely useful. Get familiar with topographical maps, at bare minimum, and preferably other types you think might be appropriate. Study some cartography. Go out on a compass navigation training course - with not a single gadget on you.
I mean that about the training course, too. You'll learn much better that way, and learn things properly. Don't just think reading a book cuts it, you need to go out and get experience where you still have someone to pull you out or ask questions of.
Get the permission of the local authorities. Others have outlined why that's a very good idea.
I'd also suggest going on a few multi-day bushwalks before you leave. On at least one of them, preferably with someone experienced, leave your GPS unit at home. Why: (a) Bushwalking is fun, especially multi-day trips (b) it'll make you more confident in your ability to handle navigation and the work involved, and (c) you'll appreciate the practice.
Now, I've made some big assumptions about the sort of territory and environment you'll be working in. Even if you don't need the skills outlined above, though, they're darn good to have, darn fun to acquire, and it never hurts to be prepared.