This instrument works on the principle of differential image motion monitor, and is called the seeing monitor. It consists of two apertures seperated by one meter, and is pointed towards the polaris.
This is a wide angle CCD camera, with a field of view of 60 degrees; it is used to take sky images for cloud estimation.
A pair of Micro Thermal sensors seperated by one meter and mounted two meters above the ground; a similar pair was mounted eight meters above the ground (not seen in picture). They were used to estimate the ground layer contribution to seeing. The box near the feet of the man is the data-logger.
A Nikkor camera lens mounted on a ST-6 CCD camera is used to measure extinction; the guidescope is also seen in the picture.