Multifaceted radiation detection and classification system

One or more computing systems of a radiation source detector to generate a metric relating to a source of radiation in measurements of radiation, the one or more computing systems comprising:

• one or more computer-readable storage mediums storing computer-executable instructions, execution of which causes the one or more computing systems to:
• access a source signature of the source and an estimated background;
• generate a background vector factoring out the source signature;
• generate a projection vector based on a weighting matrix derived from the estimated background and based on the source signature and the estimated background;
• access a measurement;
• generate the metric based on the measurement, the projection vector, and an expected variance and an average background;
• and
• when the metric satisfies a threshold, output an indication that a presence of the source has been detected;
• and
• one or more processors for executing the computer-executable instructions stored in the one or more computer-readable storage mediums.