A Focal Plane Array is an array (e.g., a grid) of
radio receivers at the focus of a Radio Telescope,
i.e., at its Focal Plane.
Bolometers may be used as the receivers.
With it, Radio images can be made, as a photographic plate
or CCD at the focal plane of an Optical telescope
Atacama Pathfinder Experiment (APEX)
Green Bank Telescope (GBT)
Westerbork Synthesis Radio Telescope (WSRT)