SNAP: VLF/LF statistical noise analyzer

The statistical noise analyzer (SNA) was designed to analyze very-low-frequency (VLF)/low-frequency (LF) highly impulsive atmospheric electromagnetic noise, which is largely produced by lightning discharges. The statistical noise analyzer portable (SNAP) laboratory model is the second generation of the original SNA. In addition to the original SNA functions, the SNAP lab model provides a prototype for a compatible, deployable system that will allow expanded remote data collection and more detailed laboratory analysis of VLF/LF noise. Real-time noise data from a VLF/LF antenna system is input to the receiver/sampling unit. The unit then bandlimits the signal, detects its envelope, and outputs a digital representation of the data. The resulting digital data are inputted electronically into the SNAP computer for statistical analysis. The SNAP lab model performs statistical analyses, and the results can be stored in a file, printed, displayed on PC CRT, or plotted