For this problem please refer to the following discussion on Dempster-Shafer (D-S).
To combine the evidential intervals for each sensor and declare a fused declaration of target identity is explained by the following four points adapted by Dr. Hall from Glen Shafer's book, A Mathematical Theory of Evidence, Princeton University Press, 1976.
The product of mass assignments to two propositions that are consistent leads to another proposition contained within the original. Suppose that sensor 1 assigns evidence to proposition a₁, (m₁(a₁)), and that sensor 2 assigns evidence to proposition a₁ (m₂(a₁)). These assignments of evidence reinforce each other, yielding a joint probability mass of m(a₁) = m₁(a₁)m₂(a₁).