Abstract : The development team responsible for creation of the automated aerosol and xenon sampling systems is continuing to solve problems related to the operation of automated systems for nuclear explosion monitoring. Several typical problems are presented here to characterize that effort. First, the development of tools for the efficient use of state-of- health information is in progress. Second, first-generation code segments useful for authenticating data have been developed and are discussed. Finally, the computations and experiments quantifying the effects of cascade summing in the operation of aerosol monitoring radiation detectors are discussed. Both the Radionuclide Aerosol Sampler/Analyzer (RASA) and the Automatic Radioxenon Sampler/Analyzer (ARSA) gather state-of-health data (Miley, 1998; Bowyer, 1999). These data are stored and forwarded to a data center, such as the US National Data Center. Tools to simply visualize (with template eye guides) have been constructed. State-of-heath data from operational RASA units and specially designed experiments have been analyzed to demonstrate the ability to detect minute trends leading to failure. This analysis should allow systems maintenance staff some predictive capability. Providing a digital signature on a data transmission serves to authenticate both that the message comes from a trusted source and that it has not been altered in any way. In addition, digital signature also makes the message undeniable: that is, it cannot be disputed that this message came from some other source or was fabricated. Authentication software has been produced in collaboration with Sandia National Laboratories and has undergone extensive testing on operational and test RASA units. Authentication code must implement the policy logic of an overall authentication infrastructure. Policy decisions for data authentication have not been completely set at this time.