Control and evaluation of diffuser screen system of WFST

The wide field survey telescope(WFST) is a new generation optical telescope under commissioning in China at the present stage. Designed with a field of view(FOV) of 3 degrees and equipped with a 0.765 gigapixel mosaic CCD camera, the telescope will be used to survey the northern sky in multiple optical bands each night. To optimize the data, a diffuser screen system is designed to evaluate the inhomogeneity of the entire telescope system, which includes a diffuser screen, lighting module and system control module. The correction parameters from diffuser screen system will be very helpful to improve the accuracy of subsequent scientific data in data processing. For this purpose, the control module of the diffuser screen system is developed and some measurement are proposed. The correction methods and algorithms are achieved based on the operation of the diffuser screen and the corresponding screen data, which can make the system better used in observation of WFST.