Hi Jez

Something like this.

Two events have to happen simultaneously (within 10nsec) if they do, a log is taken of the exact time they occured (GPS locked). Hopefully the events happen rarely enough that the logging can be done per event, otherwise multiple events are logged in "bins". When the bins in a buffer are filled, the array transfers to another buffer while the first is emptied of the observations, compressed and stored for later analysis.

The best time lock I can get has an uncertainty of less than 30 nsec RMS.

Nasty isn't it ? Is it even feasible ?

Steve