Implementing CBOSS
Sat, 2007-07-21 06:52 — hcroze
In the context of CBOSS (the Cell-Based Observational Sampling System), we need to get cracking on outfitting the team of Maasai Scouts with handheld GPS units and mobile phones. I've started looking seriously on the web, since the local Garmin dealer was quoting with a mark-up of 250% and seems to be uncertain about availability of models (says the basic eTrex will not be any longer supplied as of end-July -- no news of this at http://www.garmin.com/). We need 15 units (one each for the scouts, one for David Sitonik for training, one spare).
So, at least five questions we can address in this topic:
- Data scope and collection protocols: How can we make best use of the nascent CBOSS proposal to organise the scouts to gather systematic and reliable data on elephant occupancy of the ecosystem.
- Ideal GPS model: best combination of functionality (track capacities, waypoints), ruggedness, battery life, size, etc.
- Ideal mobile phone model: low cost, minimun feature set, possibility of GPS/GPRS tracking...
- Sourcing & Shipping: most efficient, cost-effective route to get the units here.
- Training & deployment: training the scouts and getting them reporting systematically.
If you have comments on any one of these four items, please click on its link and add the comment under the appropriate heading (they've come out in decending order - sorry about that). Thanks.
| Attachment | Size |
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| Garmin _ Compare_eTrex_toprange.pdf | 163.06 KB |
| Garmin _ Compare_eTrex_midrange.pdf | 173.46 KB |
| Garmin _ Compare_eTrex_lowerrange.pdf | 166.92 KB |
1. Data scope and collection protocols
To cover a number of data-related topics, for example: What is the breadth and depth of data that we can expect the Maasia Scouts to collect? How to we ensure a reliable sample frame? How do we account and correct for sampling biases? How can we expand the basic protocol (eles, signs) to include usage patterns such as trails as an input to ecosystem planning and management? And, I'm sure, many more.
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HC
GPS/GSM collars
One component of CBOSS will be advantitious deployment of GPS/GSM collars (see note below in reply to this intro). The National Geographic Society has provided us with a grant that will defray part of the costs. Iain Douglas-Hamilton has offered to help with some technical advise to get us back into tracking mode: we haven't put a collar onto an Amboseli elephant since the 1980s. Meanwhile, our Tanzanian colleague, Alfred Kikoti, has collared at least ten Amboseli eles on the other side of the border. Several meetings have been held with Alfred to discuss identities and data sharing.
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HC
Blurb on collars for Born Free
Winnie Kiiru asked for a couple of paragraphs of background information for a Born Free event in November 2007 in which wildlife artist Angela Chidgey will donate the proceeds of sales to AERP, specifically for elephant tracking collars. (Thanks, Winnie!)
Herewith a draft, based on the rather terse extraction from the proposal:
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HC
Trail data
There is a recently posted Ecosystem Forum topic on Trails & Corridors. Please add your comments there.
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HC
5. Training & deployment
We intend to employ a local Maasai as a consultant to coordinate the work of the Maasai Scouts for CBOSS. Hopefully one of our past Scout trainees, who have attended the courses coordinated by Norah Njiraini in working with scouts as part of the training component of ATE's Community Outreach sub-programme.
The substance and timetable of the workplan is being worked out.
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HC
4. Sourcing & shipping
If we opt to get the GPS units and/or the mobile phones from a supplier in the USA or Europe (Amazon, West Marine, Garmin itself, Nokia itself) then there is the issue of sourcing and shipping. Sourcing locally will obviously be more expensive, but then there is the goodwill for subsequent service. Depends on the price differences. Currently under investigation.
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HC
3. Ideal mobile phone model
We also need to get the scouts mobile phones for reporting to Sitonik and Soila, both for routine monitoring of elephant presence and signs as well as for 'early warning' and alterting to impending incidents in the ecosystem.
We need first to identify ideal models. Same considerations as with the GPS: basic functionality, ruggedness, possibility of GRPS/GSM tracking (see Specifications in comment below).
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HC
Phone specifications
Rich Owings, whom I contacted through his blogs (see http://GPSTracklog.typepad.com and http://GPSTrackingSystems.biz), has asked for more clarity in our requirements. He says, "Are you looking for handheld GPS units or a cell phone tracking system or...?" So...
The cellphones are required for the usual phone functions, in particular to report to Soila or David if there is an incident that requires their attention (or that of KWS, the police, etc). It's to aid rapid response. If the GPS functions outlined above could be integrated into the phone, all well and good, bearing in mind the following:
Cost is obviously a consideration. If the units are less than around $200 each, we could probably squeeze out of the current budget. Otherwise, we would need donor assistance.
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HC
2. Ideal GPS model
The Garmin family first comes to mind, something of the ilk of eTrex or the GPS 60. I've downloaded some comparisons from http://www.garmin.com/ and will try to summarise over next few days. Although the local agent (Titan Aviation at Wilson Aerodrome) seems a bit disorganised, at least there is an agent). Magellan seems less promising, and I haven't found an agent yet.
Ideally it would be great if we could find a robust device that would have both mobile phone and most GPS functions (particularly tracking and waypoint recording), but no one seems to know if there is anything suitable out there yet.
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HC
GPS specifications
Rich Owings, whom I contacted through his blogs (see http://GPSTracklog.typepad.com and http://GPSTrackingSystems.biz), has asked for more clarity in our requirements. He says, "Are you looking for handheld GPS units or a cell phone tracking system or...?" So...
The basic GPS requirements the Maasai Scouts need are (a) waypoint recording (location, date and type), (b) tracking (primarily to create a periodic record of where the scout has wandered).
Concerning (a), the 'typology' would ideally be specialised, that is, instead of Golf Courses and Picnic Sites, it would include;
Obviously, if programming a specialised typology in the device would make it hugely expensive, then we have to devise a work-around, for example, a convention that would code the built-in iconography of the GPS to our own needs (Golf Course = dung piles, Picnic Site = broken vegetation, etc.
Concerning (b), tracking, we want to create a record of search effort expended by the scout, either by simple inspection of his trail as to where he went and where he didn't go or by creating kernel surfaces of probability using a suitable tool in ArgGIS. The idea is to distinguish between genuine nulls and no sample (i.e., were there no sightings in a particular area because there were no eles there or because the scout didn't visit that area?).
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HC
Tracking management system
The RiverCross BlueTrax system can ingest and export ArcGIS shapefiles, so the client's work area can be customized with topomaps, waypoints, etc. We currently have one unit on the new project Toyota Landcruiser and on elephant from the VA family, Vicky. More information to come...
GPS suggestions
First of all, I would definitely recommend a Garmin. GPS devices are complex, but Garmin has the most intuitive interface of any manufacturer.
Second, consider reception. If you are dealing with any areas of dense canopy or other barriers to reception, consider a unit with a high-sensitivity receiver, like the new Garmin eTrex H-series (http://gpstracklog.typepad.com/gps_tracklog/2007/05/new_garmin_etre.html). A pricier solution would be the 60Cx.
Third, is there value in tracking / recording elevation? If so, a unit with a barometric altimeter may be useful. This can always be estimated from lat/long if good enough topo maps are available.
Hope this helps.
Garmin it is, then...
The consensus is clear: Garmin. Certainly would appear to be the best choice with regard to local support.
We have no real canopy issues in the Amboseli ecosystem -- mostlyopen bushed grassland. Also, we are not really interested in elevation: the ecosystem is generally flat and there are good topo maps at 1:50k.
The eTrex H looks fine, particularly with regard to price. Just talked to the local agents (Titan Avionics). They don't have the units in yet: two weeks. They are quoting $200 per unit, which is quite a markup. They muttered something about a 10% discount if we buy 15, but are putting the question to the new boss (Raju). I wouldn't mind a reasonalble markup for shipping, clearing, support good will etc, but 100% is a bit steep.
Two technical issues with the eTrex H. One is that it doesn't seem to have a USB interface. Not a terminal condition, but it means we'll need to use serial-USB converters. The other is that the battery life is listed as 17 hours, which is a bit low compared to the 22-32 hrs rated for other units (GPS60, 28 hrs!). Again, perhaps not a terminal excluder, since it's somewhat better than the low value of 12 hrs I've seen for others.
The GPS 60 was also the next on my list of possibilities. Long battery life, USB interface, rugged. It is pricey ($194 on the Garmin website, $475 (!!) quoted by Titan. I shall write the director about a possible discount on that one, too.
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HC
PS: This just in. Titan has quoted $140 for the eTrex H, Four week delivery time.
eTrex vs. GPSMAP 60C
That's a mapping GPS (I own its brother, the 76C, same electronics in a different case), and meanwhile obsolete through the newer Garmin GPSMAP 60Cx.
But since we don't need mapping (no loadable maps available for the area), it is actually not the right device.
Haven't looked at the eTrex model range, but isn't there an eTrex that does exactly what we need, including a USB port?
17 hours is plenty, particularly since the device doesn't have to be on all the time. I guess that would last almost a week in normal operation.
Hans-Georg
eTrex family of GPSs
Good point, Hans. To get a better view of all the eTrex's, I made three compare sheets (attached above under this topic intro) from the Garmin website, for the lower, middle and top range units. It's not till you get to the middle range and the over-$200 territory that there's a USB. You also start to get overkill of features, including compass, micro SD card slot, that sort of thing.
Need to study further, but looks like, if we can live without a USB interface and ensure a ready supply of batteries, then the basic xTrex H looks best for the money. If we really can live without a USB interface and battery life is an issue, then the Summit or Venture would seem best. If USB is essential, then the Venture Cx would be the choice (given that the Venture HC, also a USB, only has 14 hours of endurance). The USB would basically cost an extra $100 per unit, whereas, I think I have a USB-serial cable lying around here somewhere. Anyone know how seamlessly the cable works?
See what you think.
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HC
More eTrex considerations
Several more things to consider:
If you can live with the serial interface and monochrome screen, the basic eTrex H looks like it could be the best unit for you. Maybe you can get one and try it out before buying all of them.
Serial connection, etc.
I know from own experience and reports that not all USB-to-serial adapters work with the Garmin receivers. But I have used one myself, and that worked very well. We may have to test and try one or two. Fortunately they are not expensive, and once they work, they always work.
Mapping is probably not needed, as the researchers know the area very well. I've looked into map-making, but as you say, it's not for the faint-hearted.
The is a funny organization that sells you the special Garmin plugs. I've used them myself to make Garmin cables. But in our situation this is probably not a good way to do it. Fortunately we need only one or two of these cables, if I'm not mistaken.
I agree with the eTrex H choice. I suppose it can record the track, but am not absolutely sure.
Hans
eTrex H
My experience with serial:USB adapters is that the name brands tend to work fine.
You're right; you don't need a cable for each, unless each unit will be used with a separate computer at a separate site. Otherwise, one or two would do fine.
The eTrex H will record up to 10,000 track points and 10 tracks. It will also record 50 waypoints.
HTH
Tracking
A little ambiguity crept in here. The word tracking is often used for systems with the capability that the GPS device can be tracked down (particularly against the knowledge and will of the bearer). One technical solution for this is that the GPS receiver is combined with a mobile phone or satellite transmitter and reports its position that way.
For now we don't need that, particularly since such tracking devices are much more expensive, although it would be nice to stick such a device onto an elephant.
What we need, and where the word tracking comes in, is that the device stores its own track for later offloading into a computer. That's all that was meant when the word tracking was used here. Most handheld GPS receivers do that anyway.
Hans
HGM on batteries
In an email, 21-Jul, HGM writes:
"One afterthought: if you order GPS devices, think of a few quick-chargers and enough Sanyo "eneloop" rechargeable cells.
"I recommend to buy a few good ultra-quick chargers. Even though they are more expensive, they'll redeem some of their price by not needing double sets of batteries and by being able to fully recharge batteries during the limited times of electricity.
I think you need only buy as many batteries as the devices can hold plus very few spares, maybe two sets, if they are all kept in a centralized place like [ERH]."
Solar battery chargers
The Sanyo eneloop batteries (where did they get that name?) certainly appear to be among the best batteries around. A charger in the office at ERH would be only a partial (and necessary) solution. The Maasai Scouts are out in places with very few plugs in walls (actually, with very few walls at all). For them, we really need solar chargers. Need to search for a source of AA solar chargers.
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On 14-Aug-07, Steve Gold wrote:
"...your question of eneloops, I have no experience with this so I referred it to Bruce. He says:
" 'I did a quick web search and it appears that these are NiMH batteries (standard sizes AA, C,etc). The difference seems to be a lower self discharge rate. This would be useful to allow longer storage in a charged state. Solar charge regulators are by and large designed to work with Lead Acid Batteries (flooded and sealed). I am not aware of any commercially available solar charge regulators that are designed for other types of batteries. Bruce Roush, VP Technical Services, Solar Depot, 707-766-7727, xt 114.'
"There may be a way of charging these, but it might take some digging around. Perhaps Mark Eddy has some knowledge of this. You are charging the Nicads at higher voltages, so you might try one battery..."
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Did more searching and found at least 4 solar chargers taking off from treehugger (seems a good site, but the way), ranging from ca. $20 to $170(!). Guess we will invest in a number of the lower-priced one for the Scouts.
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HC
eneloop
A little technical background info:
eneloop accumulators are modified NiMH (Nickel Metal Hydride) accumulators. Although they have a slightly higher voltage than ordinary NiMH accumulators, they can still be charged with any normal NiMH charger. Don't fall into the trap to buy expensive "eneloop chargers". (eneloops, like any NiMH cell, cannot be charged with a NiCd charger, except for slow chargers—see below.)
You probably want a more expensive quick charger that charges them in around two to three hours. Be very wary of time-controlled chargers, which will destroy your rechargeable batteries soon.
The other, very cheap solution is always a slow charger. When the charging current is low enough that a full charge takes 10 hours or more, the rechargeable batteries are immune from overcharging, so in that case you can use very cheap chargers, and the combination is totally idiot-proof and can be left connected in places where generators are switched off and on. I actually recommend that, but the charging times from totally empty to totally full can easily exceed 24 hours with many types of cheap, slow chargers. It's still nice to know that you can't destroy the accumulators that way.
Solar chargers are more of a problem. Very small ones that fulfill the 10 hours condition are cheap, but it would take two full days or more of sunshine to charge the accumulators from totally empty to totally full. Still this could be a good solution, if the users recharge one set of accumulators every day while using another. Assuming that the accumulators are still half full after one day of use, they could be recharged to full in one day with a cheap, weak solar charger.
The downside is that you need two sets of accumulators, if you want to use the GPS every day. If you need the GPS only every other day, the cheap solar charger would be the way to go. My only remaining worry would be high temperatures when you put such a charger out in the sun on a day with no wind with the accumulators inside. The accumulators will begin to take damage when their temperature goes above some limit, perhaps around 60°C, I don't know exactly.
Hans
HGM on devices
Email from HGM, 21-Jul:
"Personally I don't know such devices, but I'm pretty sure they exist. Motorola used to have one (based on some version of Linux, by the way), and other manufacturers surely have them too.
"They would not have the same rich functionality as the better Garmin receivers, but they may still have all the functions we need. That would have to be checked carefully.
"Note also that receivers that just track and take waypoints are very cheap, small, and light, like the eTrex family from Garmin. Some are worn like a watch, like the Garmin Foretrex (https://buy.garmin.com/shop/shop.do?cID=144 ).