Previously I showed observing efficiency for BICEP3 in 2017 in 20190509_b3_obseff and BICEP3 and Keck during 2018 in 20201019_k2018_obseff. covering 95, 220GHz and 270GHz. The below looks at 150GHz.
The map making process records the number of pair-seconds binned into each map pixel. Taking the sum over all pixels gives \(4.53\times10^9\) seconds. The nominal number of light pairs in 2013 was 1240 so comparing to the number of pair seconds in a year:
\((4.53\times10^9)/(1240\times365\times24\times60^2)=0.116\) at 150GHz.
This can be compared to the numbers in the previous postings of around 0.19 at 95GHz, 0.13 at 220GHz and 0.09 at 270GHz. The reason it is coming out lower than 220GHz is probably because the focal plane yield was not great averaged over the five 2013 Keck focal planes. While the nominal number of light pairs was 1240 only 920 are marked as "good pairs" (the y-axis of the plot above spans approx. 1800 rather than 2480 for the same reason).
From 2010 to 2012 BICEP2 (a single receiver) ran at 150GHz. Here is the overall cut plot. Note that this is 3 years.
BICEP2 had 250 nominal lights pairs and the comparison of the accumlated pair seconds to the ideal is:
\((4.32\times10^9)/(250\times3\times365\times24\times60^2)=0.183\) at 150GHz.