All,

At the IRIS E & O (Education and Outreach) meeting I attended the other day
I  brought up that a  inexpensive strong motion sensor is need that could
be deployed in schools and other locations. This sensor could be placed in
schools that are in areas that can have large local events. Since many
schools are now connected to the Internet these sensors could be part of a
strong motion array notifying authorities of the amount of shaking at a
given location, assuming the Internet connections stays up long enough to
get the data out...

In a private email John Tabor in New Zealand wrote this about strong motion
data:

>Cheap strong motion is another area that most of the groups are 
>interested in.  As I think was mentioned on the list, established
>networks aren't interested in more short-period data, but they are
>very interested in more strong motion data, particularly if it can be 
>transmitted in near-realtime.  That is one of the things our 
>funding agency wants us to pursue, so I'd pleased if we can work 
>together.

So I think there is a need for am inexpensive device like this, and I would
like to add it to my product line as my first sensor. I see a need to be
able to supply sensors with my existing hardware and software. Not everyone
wants or can build a sensor...

I see being able to supply strong motion data as the most important data
that we could supply to the professional community. As John points out,
established networks aren't interested in more short-period data. I would
add that long period data is also not needed?  The PEPP project is finding
this out.  They now have a number of sensor deployed at schools, but no one
has the time, or the money,  too look at the data from their long period
devices. I found this out at the IRIS E & O  meeting I attended a few days
ago. Also, deploying sensitive long period sensors in a school, and finding
a teacher who will maintain it, has been a problem from them. 

Building, setting up and maintain a strong motion accelerometer should be a
lot easier then a high gain long period device, and senor location would be
a lot less critical. But the amount of events the device records would be a
lot less and only useful in areas with large local events. Maybe a device
could be built that could also act as a medium gain short period device as
well as a strong motion sensor?  If the device had the dynamic range, it
could have two outputs per channel orientation, one with a +-2 G
acceleration output and another more sensitive channel that could record
the smaller local / regional events.

So could an inexpensive device be built like this? When I first got the
Kinemetrics FBA-23A strong motion sensor I have online, I opened it up.
Each component (X-Y-Z) is identical with very little electronics per
channel. I don't want to duplicate it as that would be a patent problem
etc. Maybe we as a group can come up with a clever design that won't run
into patent or copyright type of problems.

Regards,
Larry Cochrane
Redwood City, PSN


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