A mathematical model of the waveform generated by man-made high frequency (HF) noise and interference is presented and discussed. The model is based on wideband (800 kHz) recordings of the noise and interference at various frequencies in the HF band. Representative examples of first- and higher-order statistics of the measured waveforms are described, including probability distributions of the envelope and phase of the noise and interference in the time and frequency domains, power spectra, autocorrelation functions, and level crossing distributions. The statistics of waveforms generated by the model closely resemble the statistics of the measured data.¿ 1997 American Geophysical Union