[time-nuts] Timing Distribution in Mountainous Terrain
peterawson at earthlink.net
Fri Sep 10 17:47:20 UTC 2010
Can you use tethered balloons at each site to obtain adequate S/N
in their position to permit time calculations to 30ns uncertainty?
On Sep 10, 2010, at 11:07 AM, Oz-in-DFW wrote:
> On 9/9/2010 2:03 PM, Ralph Smith wrote:
>> 1e-11 only buys you 3000 seconds of drift before blowing the 30 ns budget.
>> Without going to cesium we will most likely need some form of mutually
>> visible synchronization.
> Is Cesium even enough? The requirement looks like about 6 parts in
> 10e-14. That's hydrogen maser territory isn't it?
> Given the application you could probably achieve this with fiber
> back-haul that you continually range and jitter filter to achieve that
> resolution. Not gonna be off the shelf, though. Your could probably
> layer data transmission on top of this.
> Why not just periodically release a metalized weather balloon as a
> calibration target, or use one to lift a calibrated reflector in the
> event of an outage? Or pick a conventionally tracked target as a
> calibration source?
> mailto:oz at ozindfw.net
> POB 93167
> Southlake, TX 76092 (Near DFW Airport)
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