Abstract
DIMM is one of the most used instrument in site testing. However some aspects of measuring seeing with DIMM still remain unclear, for example what kind of tilt DIMM actually measures - z-tilt or g-tilt? Difference in results for these two options can be as large as 17% in integral and 10% in seeing. Here we suggest a method to ascertain which tilt is actually measured by given instrument and centroiding algorithm.
