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To verify STA's quoted read noise, SN31179 was operated in free-run, 2-d mode at different temperatures, spanning  173k to 233k.  In this test, read noise is approximated by the standard deviation along a single column, with the result averaged across all 4096 columns.  This estimate would include any contributions from non-uniformity along a column, but the result come comes out very close the to STA's quoted noise so it seems a decent proxy for read noise.  The array average pixel dark signal (pedestal, averaged along a column and then averaged across all columns) increased nearly linearly, suggesting that thermal leakage is not dominant.  Over the same range the calculated read noise increased modestly, from 4.1e to 5e.

2d Read Noise vs. Temperature                                                                                1d Read Noise vs. Frame Rate

Switching to 1d mode and using the external trigger feature to set the frame rate, a sweep of read noise vs 1d frame rate was obtained.  In this measurement the standard deviation along a column gives the temporal variation in a summed column, since in 1d mode all columns are summed to a single value.  The measured pedestal decreases as rate increases, as might be expected if thermal leakage is a significant factor, but the 2d tests suggest that it is not.  The noise also decreases significantly as rate increases.  It's roughly equal to the 2d noise at the slowest measured rate of 10Hz, but drops by a factor of two by the time the frame rate reaches 50Hz.  This requires further study, as it's unlikely the read noise is as good as 2.5 e.