Techniques, systems and apparatus are described for operating a multimode passive detection system (MMPDS). System control settings including operating parameters for the multimode passive detection system are stored. Detector signals are processed to reconstruct an image of a scanned volume and identify an object in the scanned volume based on the reconstructed image. The operating parameters and the detector signals at different processing stages are recorded. An operational health of the multimode passive detection system is monitored. Monitoring the operational health includes receiving information representing the operational health of various components of the multimode passive detection system, and determining an operational health status of one or more of the various components of the multimode passive detection system based on the received information representing the operational health of the multimode passive detection system.