You got it, however: It only matters relative time. Start and Stop times
will be known, and that is solved.
Someone has proposed using TV or other broadcasting carrier as reference
clock: this can be another very cheap solution. There are many AM
stations near the places we chosen, and these can be used.
A problem found was how to increase SNR: do you have a solution for
this? If possible this method would be the best, since longer baselines
could be made. The distance from the carrier source is not a problem
since we'd use a GPS module at each telescope. Also the software part is
not a problem too.
Good the relative timestamp also, as it saves HDD space.
Regards,
Ilia.
On 05/04/16 15:28, Chris Albertson wrote:
One more comment. It seems to me time-raging events is hard because you
need many very good clocks that tracks absolute time.
If you redefine the problem to be "determine the time difference between to
events that occurred a couple nights ago it might be much easier. This
does not need to be done in real time
On Wed, May 4, 2016 at 8:25 AM, Chris Albertson <[email protected]>
wrote:
Maybe there is some simpler way to synchronize the telescopes. Do they
even need to know the absolute time? I think only relative time maters.
For that all they need is some kind of a signal that all the telescope can
"see". Could they use an FM or TV broadcast station? They could sample
and record the signal at a very high sample rate (maybe 4X the career
frequency) and record their data at the same time. each telescope would
need to know its distance to the broadcast antenna.
The idea is to make the hardware cheaper and simpler and put all the
"work" on the post processing software developers.
For this purpose, measuring the time difference of photons detected at
different locations, I don't think the broadcast career needs to be
exceptionally stable. In post all you do to slide the recorded signal
until a best match is found. So we do need a modulated carrier. We also
have LOTS of data to use to compute the time alignment because you do it
later, we'd have billions of samples so it should be immune to noise
--
Ilia Platone
via Ferrara 54
47841
Cattolica (RN), Italy
Cell +39 349 1075999
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