[extropy-chat] Worldwide SOS system
dgc at cox.net
Wed Oct 5 23:58:53 UTC 2005
Emlyn proposed a system with the following characteristics:
"transmitter" fits in a one-gallon container and has a very long shelf life.
Receivers are in orbit.
Rugged, robust, dead simple.
I think we need to add: satellites must be cheap and offer coverage in a
preferably less than two hours.
Sorry, Emlyn, but radio can do all of this for a lot less money than
Use a highly simplified radio that is designed to broadcast at a low bit
a narrow bandwidth. This yields a high Eb/No (energy per bit) even with low
power. The assumption is that there are only a few transmitters at any
given time. in
any particular part of the world,
You can get arbitrarily long shelf life for a simple battery. For
example. use a
lead-acid battery, but keep the acid in a separate sealed container
until you need to
use the radio. You can get a lot of energy in a half-gallon container.
The radio would
be detectable from simple satellites for at least two days after you
pull the tab. The
satellite would notify the emergency response team, which would fly over
to localize the transmitter. No need for GPS, cell phone, or even
primitive AM radio,
I think the emergency transmitter including container, battery, and
acid, could cost
less than $20.00, Add GPS, FM receiver, AM receiver for less than an
and a transponder system (to speed up localization after the response
team gets to the
area) for an additional $10,
Fifty satellites at $100,000 each would give great coverage and would be
a one satellite that is capable of the imagery your system requires.
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