  The constrained energy minimization (CEM) and matched filter (MF) are two
most frequently used target detection algorithms in the remotely sensed
community. In this paper, we first introduce an augmented CEM (ACEM) by adding
an all-one band. According to a recently published conclusion that CEM can
always achieve a better performance by adding any linearly independent bands,
ACEM is better than CEM. Further, we prove that ACEM is mathematically
equivalent to MF. As a result, we can conclude that the classical matched
filter (MF) is always superior to the CEM operator.

Methodology