  Quantum light generated in non-degenerate squeezers has many applications
such as sub-shot-noise transmission measurements to maximise the information
extracted by one photon or quantum illumination to increase the probability in
target detection. However, any application thus far fails to consider the
thermal characteristics of one half of the bipartite down-converted photon
state often used in these experiments. We show here that a maximally mixed
state, normally viewed as nuisance, can indeed be used to extract information
about the position of an object while at the same time providing efficient
camouflaging against other thermal or background light.
