Inst Spectrum (Digital Demod)

When Digital Demod is enabled, the Inst Spectrum (Instantaneous Spectrum) trace is the frequency spectrum of the pre-demodulated time data. The time data is windowed and passed through an FFT to create the Inst Spectrum display.

If Pulse Search is ON, spectrum trace data is the results of the pulse search. If averaging is on, the Inst Spectrum does not show the effects of averaging. To see the effects of averaging, use the Spectrum trace data.

The following block diagram is part of the Digital Demodulation Block Diagram and shows how the Inst Spectrum is created.

The Inst Spectrum trace is derived from pre-demodulated time data, which is 20% longer than the Result Length.

$image\blk_instSpectrum_wmf.jpg$