  When observing from the ground one has to deal with the turbulence from the
atmosphere and the turbulence caused by the telescope's surroundings. In order
to find the best sites for future solar telescopes and develop multi-conjugate
adaptive optics (MCAO) for them, the contributions to seeing have to be
characterized for heights up to at least 12 km above the telescope.
  This characterization is done with a method that measures differential image
displacements using several subapertures. By extending the ordinary DIMM- and
S-DIMM-methods to measure displacements at different field angles, the height
distribution of seeing can be measured. This extended method is called S-DIMM+,
where the letter S denotes the use of the Sun as source and the + signifies
that it is an extension of the former methods.
  Observations are made with the Wide Field Wavefront Sensor (WFWFS) mounted at
the Swedish 1-m Solar Telescope (SST) at La Palma. The results from these
measurements are compared with the Shadow Band Ranger (SHABAR), also mounted on
the SST.
  The first results of these comparisons show good correlation between the two
instruments for heights up to 500 m. Results from the WFWFS also show that the
dominant seeing at this site comes from layers close to the ground and at high
altitude and that Fried's parameter, r_0, is larger than 40 cm for the
intermediate layers.
