Mobile Differential Image Motion Monitor for Astroclimate Research

A differential image motion monitor (DIMM) has been developed and manufactured to studyatmospheric seeing. The monitor is made in a lightweightfield version and can operate without a telescope,as has always been the case before. Two apertures are made using 70-mm lenses with a focal distance of900 mm. The distance between the aperture axes is 300 mm. The images from the apertures are combinedin the plane of a single CMOS camera operating at up to 314 frames per second speed with low readingnoise of about3e(-). The device also includes a3(degrees)x3(degrees )field of view viewer for pointing at a star. The monitorproved to work successfully during several astroclimate study expeditions. The monitor data were verifiedby comparing them with the results of atmospheric seeing measurements at the 2.5 meter telescope of theCaucasian Mountain Observatory