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Post by cabintom on Nov 11, 2014 16:51:37 GMT -8
When I return to Africa I'd like to do so with a GPS unit in hand... problem is, I don't know what I should be looking for in such a device. I'm thinking of using it to keep from getting lost, keep tabs of location/altitude of catches... that sort of thing.
Any suggestions?
Thanks,
Tom
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Post by africaone on Nov 11, 2014 23:32:03 GMT -8
The mots useful information are the coordinates and altitude. Of course a name of village or something like that is necessary.
Is your question relied to making label or just keeping datas ?
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Post by lepidofrance on Nov 12, 2014 2:00:12 GMT -8
GPS is, of course, very useful on the ground. That said, thanks to Google Earth, we can easily retrieve data collection (altitude, geographical coordinates) for the preparation of labels.
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Post by nomihoudai on Nov 12, 2014 2:30:25 GMT -8
I would go with something sturdy, some small waterproof Garmin. Forget about the altitude, a good working altimeter that doesn't need much calibration costs several $100. Not worth it when you can just look up the altitude afterwards with the coordinates. All the small Garmin can just track your path and you can save way points to find them back. There is no topological information whatsoever but I have just been fine so far using them. The base maps also just show major cities but this is also fine for the price in my opinion. Nowadays you could also just opt for a waterproof smartphone but I doubt network coverage where you want to go.
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Post by jshuey on Nov 12, 2014 6:20:09 GMT -8
When I return to Africa I'd like to do so with a GPS unit in hand... problem is, I don't know what I should be looking for in such a device. I'm thinking of using it to keep from getting lost, keep tabs of location/altitude of catches... that sort of thing. Any suggestions? Thanks, Tom It sounds like you want to be able to display a head-up map with your location on it. The deal is that you can spend a lot of money on a unit that does this and more. At work – we currently use the Trimble Juno – which lets you zoom in and out of maps, take geo-referenced notes, and so on. These puppies cost about $1,500 a pop! Over the next year, we are transitioning to “cell phones”! A good phone can work as a GPS unit even with no cell-phone signal (in fact, you will run up your bill if you are using data in the field – so this gets turned off – otherwise the phone dynamically uses on-line maps and runs your bill way, way up!)). You have to download all the maps you are interested in upfront of course (which is how a typical GPS works as well), but once you are in the field, you can have maps up, and GPS on. You can zoom in and out of your maps – and most importantly, see where you are located. You can also record any and all info you want for a set location. Plus it’s a phone (in theory)! John |
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rjb
Full Member
Posts: 187
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Post by rjb on Nov 12, 2014 6:31:27 GMT -8
I use a garmin gps wherever I trek, mostly to record how far I hiked and to avoid getting lost. Also if I collect detritus or anything for later processing, I record the location/elevation. The gps often loses satellites in deep canyons and was useless under the canopy in the Amazon. If I search the web before travel, I often can download free topos of the area I will visit. For example Iceland has a freely available detailed map. To avoid getting lost, I always carry spare batteries, other maps, and a compass. Anything electronic might fail.
Rick
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Post by cabintom on Nov 12, 2014 8:06:53 GMT -8
The mots useful information are the coordinates and altitude. Of course a name of village or something like that is necessary. Is your question relied to making label or just keeping datas ? Yup, for determining label data and to keep myself from getting lost. |
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Post by cabintom on Nov 12, 2014 8:13:06 GMT -8
GPS is, of course, very useful on the ground. That said, thanks to Google Earth, we can easily retrieve data collection (altitude, geographical coordinates) for the preparation of labels. Initially I wanted to rely on Google Earth to retrieve data. Unfortunately, at the moment our internet connection in Bunia is so slow we can't load Google Maps in a reliable way (it'll sometimes eventually load, but waiting half an hour for the imagery to load is not ideal.) |
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Post by cabintom on Nov 12, 2014 8:17:25 GMT -8
Over the next year, we are transitioning to “cell phones”! A good phone can work as a GPS unit even with no cell-phone signal (in fact, you will run up your bill if you are using data in the field – so this gets turned off – otherwise the phone dynamically uses on-line maps and runs your bill way, way up!)). You have to download all the maps you are interested in upfront of course (which is how a typical GPS works as well), but once you are in the field, you can have maps up, and GPS on. You can zoom in and out of your maps – and most importantly, see where you are located. You can also record any and all info you want for a set location. Plus it’s a phone (in theory)! John I hadn't realized smartphone GPS technology had progressed that far. Is there a particular GPS application you are using? Tom |
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Post by exoticimports on Nov 12, 2014 8:38:40 GMT -8
The problem with using a phone for GPS is that if you are out of GSM signal area the phone tries energetically to find a signal, and eats up the battery, possibly in just a couple hours.
Like rjb said, many GPS won't work under canopy. You may want to test a few units before you buy.
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Post by jshuey on Nov 13, 2014 5:20:14 GMT -8
I hadn't realized smartphone GPS technology had progressed that far. Is there a particular GPS application you are using?
Tom
So - I talked to our GIS gal and here is the low down. So we started with 15 Trimble Junos and after 4 years only 10 of these still work. Given the cost of replacement - we are going a cheaper route.
I’ve been told that either of two options will work for us and that we will probably mix and match. Both systems create files that can be downloaded into GIS systems. Everything we do in the field gets moved into an Arc Map system.
Android-based cell phones are ok – but then, many people already have them so they are almost free. The downside is that they have limited memory, and will only hold so many maps. Our staff that go this route will have to download specific project area maps each time they work at a new site if they want air photos and topo maps for a heads up display. (Note that we use WiFi, not data plans to move data with phones to save money). If all they need to do is record way points at a site or make geo-referenced notes - then you don't really need to have a map to look at.
The other option is to use a GPS enabled IPad. This has the advantage of larger memory and larger display size if you really want to use it as a map. It is more likely that you can download a set of maps or air photos that will work for a larger area. If we go this route – we will probably look for used IPads to save money and they will essentially be dedicated as GPS data units. The field life of our equipment is pretty short – and we suspect that a new versus used IPad lasts about the same amount of time when dragged around by our field staff.
With both systems, you have to either access geo-referenced maps and air photos, or geo-reference them yourself. I don’t think this is all that hard to do, but then I have someone who does it for me!
I just looked - and our airphotos and topo maps for the state of Indiana take over 17 gigs of memory.
John
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Post by cabintom on Nov 13, 2014 10:11:47 GMT -8
Tom, From personal experience, I can recommend you to get one of the handheld outdoor Garmin GPS units – they are real sturdy and weather proof (certainly needed in D.R. Congo!). ... Personally I would recommend the Garmin Dakota 20 GPS Receiver for any serious researcher that still has a budget frame. Thanks for the recommendation and the advice! I really, truly, appreciate the time you put into this! Tom |
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