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| Subject: | [gislist] Chris or Bill? |
| Date: |
07/06/2005 01:05:01 PM |
| From: |
Mark Martens |
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Chris and Bill:
Sorry, I appear to be getting you and Bill Diaz mixed up. I can't tell which one of you wrote what...
Either of you live anywhere near Washington DC?
Mark
Bill Diaz <william.diaz@comcast.net> wrote:
Chris,
See below:
>-----Original Message-----
>From: Chris 'Xenon' Hanson [mailto:xenon@alphapixel.com]
>Sent: Wednesday, July 06, 2005 11:11
>To: Bill Diaz
>Cc: 'Mark Martens': gislist@lists.geocomm.com
>Subject: Re: [gislist] How about tracking a group of Hikers in
>real-time?
>
>Bill Diaz wrote:
>> Your biggest challenge would be to design a system which
>would provide
>> coverage over the entire area.
>> Hiker Equipment considerations:
>> Must be low weight, low volume.
>> Must have battery capacity for more than 24 hours.
>> Must be water proof.
> Seems like you might have to cobble something together yourself.
> There are a number of radiomodems out there of varying
>capability. Operating in the HF
>or HAM frequencies you could get decent range. Couple this
>with some sort of embedded GPS
>device and a small microcontroller to poll the GPS and
>transmit to the radio and you're
>good to go. Wrap it all up with batteries and seal it up and
>dive into the brush. You can
>use similar radio modems on the receiving PC.
These all require skill levels and resources not usually available to event
organizers with limited budgets.
> Of course, it never works that easily, but rolling your own
>may give you more
>flexibility than trying to use someone else's gear.
> Another possibility is to use shorter-range radios, but use
>a repeater in a chase
>vehicle to collect and retransmit the data to home base. This
>would allow for smaller
>radios and antenna on the hikers as long as you had bigger
>antennas (and receiver
>amplifiers) on the relay vehicle.
This would require considerable resources and technical assistance at each
event.
> I have a couple of old Metricom 900Mhz radio modems
>(formerly from the Ricochet
>wireless ISP network) that can be set into a mode called STRIP
>(StarMode Radio IP) where
>they form a virtual relay network -- any node receiving a
>packet of data relays it to the
>other nodes who haven't gotten it yet. This allows a node to
>communicate from A to B to C
>even if node A can't reach node C directly.
> You can find old Metricom modems very cheap on eBay. If you
>want to play with a couple,
>I'll sell you the ones in basement for whatever the going eBay
>rate is, I'm done with
>them. They are smaller than a paperback book (a little bigger
>than a pack of cigarettes)
>and have an internal battery that they can run on.
The Garmin Rino solution is low tech, short range, portable, weather proof,
and may be acquired for a reasonable sum. It would be possible for
non-techies to set up a workable network, with some remote help from
techies.
Obviously, the Garmin Rino solution would not be suitable for all events,
but for small events with limited budgets and resources, it may be something
to consider.
Bill
>--
>Chris 'Xenon' Hanson, omo sanze lettere Xenon
>AlphaPixel.com
>PixelSense Landsat processing now available!
>http://www.alphapixel.com/demos/
>"There is no Truth. There is only Perception. To Perceive is
>to Exist." - Xen
>
---------------------------------
Sell on Yahoo! Auctions - No fees. Bid on great items.
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