The beginnings of DARPA SIGMA and Kromek’s involvement:
The DARPA (Defense Advanced Research Projects Agency) SIGMA program began in late 2014 as an effort to create a scalable networked detection capability against radiological and nuclear threats from non-traditional, clandestine attack vectors: typically seen as either a radiological dispersal device or dirty bomb or other use of radioactive material to contaminate infrastructure or directly harm citizens.
DARPA saw the impact the ability to network radiation detectors together to form a large detection net that would have on radiological safety for a city, border or other location. If lots of detectors that talk to one central control room are deployed in an area then they are much harder to avoid than a large static sensor. It also means that they can quickly be deployed into an area without the need for costly setup.
The network (which came to be called SIGMA) would need a cost-effective radiation detector to provide the data into the network – without the detector, the network would have no purpose.