Present Values of the Optical Depth as Measured at the CSO

The most recently measured value of 225 GHz optical depth at the CSO is 0.109, at 21:19 UT. Current time is 21:34 UT.

The most recently measured value of 350 micron optical depth at the CSO is 4.44, at 21:18:10 UT on 2009-11-21. With a scaling factor of 24.75, this gives another estimate of 225GHz optical depth of 0.179.

If you'd like to see plots of tau vs. time and/or tau cumulative distribution functions by quarter and by month, click here.

For a short explanation of the tau sky monitor instrumentation click here .