Uncertainty of encircled parameters of spot measured with array detector

The evaluation of uncertainty of spot encircled parameters measured with array detectors is the main goal in this paper. Firstly, the general definition and mathematical expression of spot encircled parameters are given. Secondly, three computation methods for spot encircled parameters measured with array detectors, including approximated encircled power method, exact encircled power method, equivalent encircled size method, are summarized and compared with each other. And the corresponding discrete expressions to the three computation methods are derived based on zero order approximation. Thirdly, general expressions of uncertainty of spot encircled parameters based on equivalent encircled size method are derived according to the transfer law of uncertainty. And then several simple forms