Present Values of the Optical Depth as Measured at the CSO

The most recently measured value of the 225 GHz optical depth at the CSO is 0.174. This measurement occurred at 02:49 UT. The current time is 03:01 UT.

The most recently measured value of the 350 micron optical depth at the CSO is 3.74. This measurement occurred at 02:41:23 UT on 2008-05-16. With a scaling factor of 24.75, this gives another estimate of optical depth at 225 GHz of 0.151.

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 .