A space-based radio frequency transient event classifier

The Department of Energy is currently investigating economical and reliable techniques for space-based nuclear weapon treaty verification. Nuclear weapon detonations produce RF transients that are signatures of illegal nuclear weapons tests. However, there are many other sources of RF signals, both natural and man-made. Direct digitization of RF signals requires rates of 300 MSamples per second and produces 10{sup 13} samples per day of data to analyze. it is impractical to store and downlink all digitized RF data from such a satellite without a prohibitively expensive increase in the number and capacities of ground stations. Reliable and robust data processing and information extraction must be performed onboard the spacecraft in order to reduce downlinked data to a reasonable volume. The FORTE (Fast On-Orbit Recording of Transient Events) satellite records RF transients in space. These transients will be classified onboard the spacecraft with an Event Classifier specialized hardware that performs signal preprocessing and neural network classification. The authors describe the Event Classifier requirements, scientific constraints, design and implementation.