Optics-less Sensors for Localization of Radiation Sources
  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. 
H.J. Caulfield, L. P. Yaroslavsky, Ch. Goerzen, S. Umansky