Portable detector apparatus

A portable detector system for the processing of data derived from incident radiation is described comprising: a plurality of separately addressable radiation detectors having at least two different known response properties;a processing device comprising: a collection module to collect data from radiation incident at each detector and produce a spectral histogram for the collected data from each detector;a deconvolution module to deconvolve the histograms from each detector to derive a single spectral histogram that representatively combines information from the plurality of detectors;the plurality of separately addressable radiation detectors and the processing device being associated together in compact and portable manner, for example within a common casing.