[hpsdr] multiple receivers - is it really necessary

[Graham / KE9H]

Mike:

There are techniques that do this, see

http://www.gpstime.com/

and read the "Timing for VLBI -2009"  presentation by Tom Clark (K3IO),
and Rick Hambly (W2GPS).

They are time stamping radio astronomy signals to (sub) nanosecond 
accuracies
and can ship recorded signals from western China back to the US, and then
assemble and post process them into "Very Long Base Line" received signals,
with an aperture equal to the diameter of the earth. Using GPSDOs as the
discipline and sync for an accurate time base.

Just time stamping to several nanosecond accuracy is enough to recover phase
information for HF signals.

So, if every member of the Austin Amateur Radio Club made his home station
available to the club station as one element of a phased array antenna 
system
during a contest...

Is it single operator or multi operator?

Is it limited to 1500 Watts transmit power per licensed location, or 
"just" 1500 Watts
total for the entire networked "antenna."

What if members of this list, in different countries, did the same thing?

:-)

--- Graham / KE9H

==
Mike Hamel wrote:
> At the risk of maybe dragging this thread too far from the intended
> topic, I had been thinking that one of the possible "big picture"
> capabilities of multiple SDR stations located within a few miles of each
> other could be a scenario where they share streaming raw data over the
> net in such a way as to create an effectively huge aperture antenna for
> receiving DX.
>
> Packet timestamping, phase alignment and the consequences of net latency
> would make it a bit off from "real-time" but it seems like it should be
> possible with internet connected SDRs.
>
> Each idle SDR could give some BW for the "shared pool" of data to be
> aggregated.
>
> I haven't a clue how this 'pie in the sky' could be implemented but it
> seems like an eventual future capability.
>
> /$0.02
>
> Mike
> WO1U
>
>   


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