Below is a graph of the seeing measured by the 1 meter Swedish Solar Telescope. The seeing is measured using the Shack-Hartmann sensor of the Adaptive Optics system, which measures the image motion in 85 subapertures of the telescope. For four of these apertures, the differential motion is calculated, and this is converted to a value for r0, similar to how a DIMM instrument works. The differential image motions measured are corrected for the image motion removed by the applied voltages on the deformable mirror, such that the r0 measurements reflect the true seeing irrespective of whether the AO servo loop is open or closed.
There is also a short-baseline SHABAR at the top of the SST tower, which also measures seeing, independent of the telescope. In the graph below, only the 3 minute running average of r0 is included.
Green indicates that the AO is running in closed loop.
Red indicates that the AO is not running in closed loop, either because it has been stopped by the observers, or because it can not lock (the latter can happen due to bad seeing, or because the observers are taking flats, or because the telescope is not pointed at the Sun).
Blue lines show a 3 minute running average of the seeing as measured by the AO.
Black lines show the seeing as measured by the AO using 8x8 pixel subfields. This method is more sensitive to high layer seeing.
Orange lines show a 3 minute running average of the seeing as measured by the SHABAR.