Abstract: Methods and apparatus for detecting and measuring electromagnetic radiation using a digital antenna are provided. Receiver apparatus includes a digital antenna having an array of pixels, each pixel configured to produce a voltage that represents received photons at a photon frequency of the pixel, and a processing unit configured to sample the voltage of each pixel at multiple sampling times to acquire a set of voltage samples and to process the sets of voltage samples and corresponding sampling times to provide information on one or more detected signals represented by the received photons.