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(meteorobs) Meteor Trails Are Being Used As Cheap Alternative To Satellite Systems (fwd)
New Scientist
UK Contact: Claire Bowles
claire.bowles@rbi.codot uk
44 171 331 2751
US Contact: Barbara Thurlow
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EMBARGOED FOR RELEASE: 12 August 1998 at 2:00 p.m. EDT
Meteor Trails Are Being Used As Cheap Alternative To Satellite Systems
Cold War Legacy Has Ended Up On The Streets Of Seattle
A COMMUNICATIONS system developed to keep the US military talking
after a nuclear war is now helping a private ambulance company
monitor the movements of its vehicles.
During the Cold War, the US military developed a method of sending
data by bouncing radio signals off meteor trails. Every day more
than a million specks of dust enter the Earth's atmosphere from
deep space and burn up, leaving trails of particles. Amateur radio
operators had noticed in the 1920s that they could bounce signals
off these trails. Although the trails last only a few tenths of a
second, there are so many that at any given time there are usually
enough for a ground-based transmitter to work with.
The high cost of developing the "Meteor Burst" system meant that
the project was cancelled when the Cold War ended. The scientists
who worked on the system left to set up a Seattle-based company
called StarCom Technologies, which has developed a civilian
version as a cheap alternative to satellite systems.
StarCom transmitters continually send probe signals to test for
reliable reflections. When a return signal is sensed, the
transmitter sends out a rapid burst of digital data at frequencies
between 40 and 50 megahertz that can be picked up over a wide
area. The data transfer rates are low, up to 20 kilobits per
second, and transmission time is limited to a few hundred
milliseconds per meteor, but this is sufficient for uses such as
monitoring vehicles' positions.
This is the purpose for which the system has been tested by a
private ambulance company, American Medical Response (AMR), which
ferries patients all over Washington State and Oregon. After
successful tests of prototypes over the past six months, the
company this week began fitting StarCom transceivers to a quarter
of the 80 vehicles it uses to serve Seattle and the surrounding
area.
All the ambulances are fitted with a global positioning satellite
receiver as well as a StarCom transceiver, allowing them to
continually report their position back to AMR's Seattle control
room. The system enables the company to keep track of where an
ambulance is and whether it has a patient on board.
"We crosschecked the StarCom data with our own computer mapping
and feel pretty confident that it is hitting the mark," says Greg
Sim of AMR.
StarCom now wants to hide transmitters in vehicles that will
automatically send out a signal if the vehicle is stolen. The
system could also be used to interrogate measuring instruments in
remote areas.
"We are using the satellites which nature provides for free," says
Guy Rosbrook, StarCom's chief executive and a former Meteor Burst
scientist. "There are so many meteors that you can regard the sky
as a wide-area cracked mirror."
Author:Barry Fox
New Scientist issue 15th August 98, page 17
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