Slashdot Mirror
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?"
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.
Well, we use 120VAC, rather. 100VAC-230VAC AC-DC adaptors are common with equipment these days, however. You may want to look for equipment that comes with such an adaptor instead of trying to step it down. Heck, even my cell phone came with one that can do 100-230.
-- dieman - Scott Dier
Even fairly basic GPS receivers come with built in compasses. Never hurts to have a back up though.
Don't blame me, I voted for Durga.
It's supposed to be funny. Laugh. :-)
Javascript + Nintendo DSi = DSiCade
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.
APRS could be your new best friend.
mstyne: real name, no gimmicks
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.
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
I think the parent poster Floodimus meant 'developing' countries instead of using the term undeveloped or underdeveloped countries, which implies an inferior society with archaic and anachronistic practices. 'Developing' country a better term to use and doesn't sound pretentious.
Bad Panda! No Bamboo for you! In matters of importance ACs will not be responded to. Want to say something critical,OK
Well, sort of. Don't depend on GPS 100%.
Infact, a hi-tech solution is nice, but the low-tech is going to be orders of magnitude more use to you. As long as you have a basic geological/terrain map, it it quite simple to put an ink based red mark and write about something you find interesting. This will be more robust than:
As for the GPS equipment? Take 3 hand held sets, tested to be rugged for terrain use: carry 1 yourself, 1 for your partner (incase you get seperated), and 1 spare in your vehicle if yours gets over doused in mud.
On all the above, I assume you're planning a reasonably independent trip, with 1-2 guides, for around 3 months. If you're going in a party of 20 with masses of guides, well much could be unnecessary.
Do your homework. GSM stands for:
Groupe Speciale Mobile
Maybe my French is rustier than I thought, but I believe that traslates (roughly) as Special Mobile Group.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
Honestly, you'll be lucky if you get the thing past customs without it being 'confiscated.' They take what they want. This happened to my friend who went to Kenya to help set up a network for his missionary friends. They just up and took a router and other bits of hardware that looked interesting to them and told him to move along. Luckily, he only had one CD of software that he kept in his pocket. He knew this was a possibility, but didn't think it really happens. It happens.
If you're going to bring a GPS device over there, get a compact one that will fit in your pocket.
"There are no such things as mutual fantasies. Yours bore us and ours offend you."
- Bill Maher
I've had a very good experience with MacGPS Pro from James Associates. It's reasonably priced ($40) and you can even find free maps and such. I used it in combination with a Garmin eTrex on a recent trip to the Okavango Delta (Botswana) and it worked just fine. No, I do not work for either company.
1. Different countries run different power. There are quite a few countries in Africa.
2. Quite a few modern pieces of electronic equipment already contain the necessary transformers to work in different parts of the world.
3. IT'S A JOKE! WHERE THE HECK IS YOUR SENSE OF HUMOR?
Yeash. You'd think the whole explanation of GPS as a setup would have tipped people off.
Javascript + Nintendo DSi = DSiCade
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
Actually, africa does not have augmentive correct signals. So in comparison to accuracy in the US they have signficantly degraded accuracy.
google for WAAS or EGNOS
Hmm...
Were you present at all these ethic cleansings all over the continent? Or was all this new found "knowledge" from your one of your CNN fed binges?
I'm African. I am in the United States and it gets really tiring hearing all these "corrupt, cleansing, wars" stories. Jesus! There was a bombing in London last week, you obviously watched it wherever you are. Now will you say there's a war there now? There are wars, like the ones in the middle east, yes but not all over the friggin continent!
Get the facts right before you make your comments. Take a trip over to Africa (which is actually made up of 54 countries and not a single entity like live8 would have us belive), observe, then you can sit on your three legged pedestel and say your favorite words - "corrupt, cleansing, wars".
Damm!
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.
Most of these posts are not going to help the submitter much at all, mostly because nobody here seems to know a damn thing about GIS. First things first, what sort of mapping are you trying to do, what information do you want to gather? Hydrology? Land use? Topology? Classification? Next most of the consumer grade stuff is crap if you want any kind of accuracy, if you want really good data, you'll need to get a base station set up and look into dgps, that means you need a better sort of GPS unit such as something from Trimble. Next, GPS compasses, be they electronic, interpolated, or what not are crap. BRING a GOOD compass. You'll probably also want a separate barometric altimeter, and a clinometer, if you don't know how to use and calibrate this equipment, then I must agree with the earlier post that amateur cartography might not be for you. As for software, again really depends on what you are trying to do? orthorectify photos? network analysis? etc...
In short, good luck.
BTW, I have SOME qualifications, a GIS minor, and my Msc thesis(in progress) is about robotic terrain mapping.
"Have fun, don't leave electronics (or anything plastic) on your dashboard - it will melt, and good luck with spelling the village names! It sounds like a fun project."
No, it won't melt. It will get stolen looooong before it can melt.
General rule of thumb: Anything that won't fit in your backpack, will get stolen and if you let your backpack out of sight for 0.000001 seconds, then it will get stolen together with everything in it.
Note that for protection, it is a good idea to carry a hunting knife, but since some places object to knives, consider carrying a small axe instead - there are no laws against axes and it will ensure that you'll be a very popular guy whenever you set up camp and need a fire...
Oh well, what the hell...
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.
They work all right, but depending on the model you might need to fork over extra money for the maps. You get the maps either on disc as a separate purchase, or they are already on the unit and need and unlock code.
Simple Lat/Long models without mapping work fine though.
Somehow I doubt there will be maps of undeveloped countries. One word of warning though - GPS are illegal in some countries. I would check before bringing one.
I tried every decent and legal way I could think of to resolve the issue w/the business before I rented the chicken suit
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.
I work in remote, undeveloped countries (doing IT, if you can believe it) and I can confidently say that your biggest problem is going to be power.
Do yourself a favour and:
Crumb's Corollary: Never bring a knife to a bun fight.
I seem to recall that its fairly simple to vastly improve accuracy of GPS by keeping it still for an extended period (days and weeks perhaps). Since the "noise" drifts around your precise location, after an extended period you can average out the noise and get an answer accurate to inches if I recall. Geologists use this trick to detect movement of tetonic plates of less than an inch, though I'm sure they are far more patient than the questioner...
My other car is a Popemobile
Wow, I would never have thought that particular experience would be something to post about on /., but here it goes.
I have actually done exactly that, some charting mission in West Africa with a GPS system (a good old Thales Scorpio).
If you need any sort of precision that requires differential GPS, your main concern is finding altimetric reference points. Those are HARD to find. Some knowledge of hydrography helps.
If a vertical incertitude of the order of the meter is good for you, your life is going to be a lot easier. No need to set up a differential station, etc.
To gather data, you can simply attach the GPS antenna on a 4x4, collect data on one of those rugged Husky hand computers, then transfer it all onto a laptop as circumstances allow, for processing. A professional-grade GPS system will come with its own processing software, so that's a non-issue.
The hardware held surprisingly well during our mission, but you will probably want a spare laptop handy.
If your needs require differential GPS, you will probably want to hire someone on the spot to guard the station while you're roaming the zone to gather your data. Wandering cattle pushing your station over can mean a day of work wasted.
If you end up using maps instead of a software, be aware of the datum http://en.wikipedia.org/wiki/Geodetic_system used in the map. Because the earth is not a perfect shape, different countries use different projections, called map datum. You should set your GPS to the same datum as the map you are using.
I was going to let this alone and perhaps let the geocaching or other GPS gadget freaks answer it, but some of the discussion regarding durability and suspicious behavior by westerners leads me to throw my US$0.02 in.
It depends whether you're going to be walking or driving. I have had very good car-based mapping experiences using an older Mac, namely a G3-500 Pismo. I have found the Pismo and similar Lombard/Wallstreet units to be cheap, very functional, unobtrusive, and very durable -- almost to Panasonic Toughbook standards. Though I use both Mac and PC on a regular basis, ease of use pulls me to the Mac for GPS tools. I use mine with a remote usb-connected-and-powered Deluo GPS unit, which mounts on the dashboard or on the roof of the vehicle using a magnet on the bottom. The Deluo has no display or blinky lights to advertise its presence; it's just a 3cmSq bump with a cable. Get a car charger to keep the Mac powered up, use the nifty Control+Alt+Apple+8 to switch the display to "7337 mode" (inverse greyscale display), and you'll be about as unobtrusive as you can get. Less obtrusive than simply being a western guy in rural west Africa, anyway.
On the other hand, if you're going to be on foot, I heartily recommend ditching the laptop and taking an eTrex Voyager or similar model. It's very durable, gets good reception, fits in your shirt pocket out of sight while still receiving a signal, and runs all day long -- thanks in part to its black and white screen -- on two AA batteries. Make a list on paper of waypoints you expect to see, mark them on the eTrex unit using the little joystick when you get to each spot in sequence, and then put it back in your shirt pocket without making a scene. Take a few sets of rechargable AAs and a solar charger, and leave the computer at home for data dumps at the end of each day.
Better yet, take two or three eTrex units (US$60-90 used), and consider them disposable -- expect to have them all eventually stolen from you or seized by various police or military. You may face less hassle and risk if you appear only mildly irritated that a trinket is being taken, as opposed to hyperventiating over someone taking all your data. Eventually you can take the downloaded data and correlate the traces and waypoints using satellite maps or other starting points.
J
I think not...(*poof*)
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.
Landsat-7 is available freely and cover the whole world, but it's only 15 m (panchromatic) and 30 m (multispectral)
ASTER L1B is also free but the cover is not complete. It's very good data with 3 bands in VNIR. 15 bands total.
SRTM-DEM, for topography, is also great and free. 3 arc-second of horizontal resolution and about 5 m vertically (relative, not absolute). It really is useful data for topography, and it's free.
Where to find this data? Start on my Remote Sensing Table http://www.matox.com/agisrs/arsist
As for software, yes, GRASS GIS works fine on MacOS X, *but*, the learning curve is very steep. I don't know MacGPS Pro. See the two other comments http://ask.slashdot.org/comments.pl?sid=155849&cid =13067619 and http://ask.slashdot.org/comments.pl?sid=155849&cid =13067710
If I were you, I would try to ask somewhere else than /.. Nothing against the /. crowd, it just doesn't hurt to have a second opinion, especially if it comes from GIS/RS experts. You can try the Applied-GIS-RS mailing list http://www.matox.com/agisrs but there are a lot of other groups of GIS/RS specialists. Good luck!
Animoog.org
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
Illegal meaning the country being visited might consider a GPS to be "military equipment". The US and most if not all Western countries don't care, but 3rd world countries may. Checking with the local consulate of the country being visited should clear the matter up.
Check here.
I tried every decent and legal way I could think of to resolve the issue w/the business before I rented the chicken suit
Not undeveloped, you insensitive clod!
WARNING: Smartphones have side effects--most of them undocumented.
Most standalone GPS's these days, except for the very cheap ones, do have PC cables as well as built-in user interfaces, so you can get the best of both worlds, but I don't know if they can run on USB power or if you'll need to mess with lots of rechargeable batteries.
Of course, if GPS is important, you need a spare one anyway, so you might as well bring both. They're fairly cheap here, so you may consider leaving one behind as a gift if it doesn't get broken, stolen, etc. while you're using it.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Be aware, however, that DEET eats plastic stuff--so keep the concentrated stuff away from your GPS equipment, as well as any synthetic clothing and such.
~Idarubicin
I only skimmed through a few of the posts, so don't blast me for being repetitive. (Like you could ever hurt the feelings of "Anonymous Coward" anyway...)
As a co-op for a nearby municipal power company, I am currently involved with a program that involves GPS. The relevant part is that we are recording GPS coordinates for every location where we have equipment - poles, pad-mount transformers, and so on.
Two major concerns were cost and accuracy. We didn't need the best accuracy possible, and it was out of our price range anyway. On the other hand, the inexpensive units would only guarantee accuracy to within several meters. That was not nearly accurate enough - we wanted something that promised accuracy of about 1 meter. From what I read and what I was told, to get that level of accuracy you need more than just a single receiver - you need at least one receiver at a known reference point. The stationary receiver should be located where you already know the exact coordinates, and it should be relatively close to where the roving receiver will be recording - say within 50km or so. At the end of the day you would download the recorded data from both receivers, then a program can analyze the data, usually resulting in sub-meter accuracy. We were somewhat lucky in that the county operates a [CORS] receiver that is plenty close enough, and the data is publicly available on the web.
There are a couple of other slightly different options for improving accuracy, too. Instead of downloading the data to a PC at the end of the day, the receiver may be able to receive a signal that is broadcast from a nearby reference. The receiver can use that signal to improve its measurements on the fly. Depending on where you are in the world, the signal is broadcast differently, but it achieves the same goals.
The last - but most important - thing to note about accuracy is the terrain. To obtain really accurate readings, the receiver needs a clear line of sight to several satellites. At least three are required to get latitude and longitude, and at least four are required to get altitude as well. More satellites means better accuracy, in general. Also to be considered is the satellites' positions. If the satellites the receiver is tracking are all in one part of the sky, the accuracy is less than if they were spread out. (I expect that most Slashdotters could figure this next part out, but I have decided not to assume anything.) What this means is that receivers work best in an open field. Near buildings or in dense vegetation the accuracy can degrade quickly.
-
I am not here to plug brands - I could care less - but I will share what little I know. I noticed one recommendation for Trimble - they are supposed to be good, but the receivers I saw were pricey. The unit we eventually settled on is Thales Navigation's MobileMapper. As long as you are not actively trying to destroy them, they work great. The PC software leaves a bit to be desired, in that it's not always easy [or even possible] to get it do what you want. As far as accuracy is concerned, after processing the data on a PC, almost all of the points have accuracy estimates less than one meter. A very few points have had terrible accuracy estimates, but those can usually be attributed to nearby buildings. Overall, we have been pleased with the results.
5. Get your shots. The night-time masquitos carry malaria. The daytime versions carry yellow fever. I might have that backwards, but really, does it matter when you contract which disease? ;~)
There are some pills that decrease the chances of getting malaria, and a shot for yellow fever (two shot series, if I recall correctly). Malarone is what I was provided for malaria 'prevention', and was told by a gal I met in the plane (who looked like hell, as she had just been in the clinic BECAUSE OF malaria) that it was the best (and she wished that she had had it).
I'm sorry, but the pc (political correct) term is "Developing Countries".
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.