  A new family of radiation sensors is introduced which do not require any
optics. The sensors consist of arrays of elementary sub-sensors with natural
cosine-law or similar angular sensitivity supplemented with a signal processing
unit that computes optimal statistical estimations of source parameters. We
show, both theoretically and by computer simulation, that such sensors are
capable of accurate localization and intensity estimation of a given number of
radiation sources and of imaging of a given number of sources in known
positions. The accuracy is found to be dependent only on the sub-sensors noise
level, on the number of sub-sensors and on the spacing between radiation
sources.
