Signal Guide

Glossary

Here you will find a list of important technical terms and their explanations.

1 Spectrum

Default display mode with largely free choice of settings for frequency range (center frequency, span) and resolution bandwidth (RBW). The device uses a FFT to capture narrow frequency ranges. If the display covers more than one FFT width, the device produces the complete spectrum by combining several FFTs together (Stitched Mode). Only the results within the width of a FFT are simultaneous because the FFTs are computed one after the other.

2 Spectrogram

The device records successive spectrums and displays them line by line using different colors and brightness (red = frequent, blue = seldom). The recording is comparable with a stroboscope recording. Frequency ranges are as for “Spectrum” mode. The sequential rate of recording can be selected according to the application and allows observation periods from 4 s up to 40 h.

3 High Resolution Displays - IQ Analysis

The device records I/Q data by demodulation within a predetermined frequency span (channel bandwidth, CBW) until the internal memory contains 250,000 I/Q data pairs (I/Q: in phase / quadrature, i.e. real and imaginary parts). The data set is available for all the following HiRes analysis types, so that they are all absolutely comparable. The display is without time gaps; recordings of up to 10 ms and resolutions down to 31.25 ns are possible, depending on the span.

3.1 HiRes Spectrogram Full

Overview computed from the I/Q data set. Shows up to 10 ms without gaps. Maximum span 22 MHz.

3.2 HiRes Spectrogram Zoom

Section of the overview. This is like looking at sections of the overview using a magnifying glass.

3.3 Persistence Spectrum - Digital Afterglow

Probability density function: Displays every incident during selected Time and Frequency Span. Color coding represents frequency of each event: red - often, blue - seldom, black - never.

3.4 Magnitude

Calculates the signal power from the I/Q data and shows it versus time.

3.5 I/Q

Enables display of the I/Q data stream versus time and allows assessment of any irregularities (jitter, heterodyning, amplitude differences I vs. Q). Time resolution down to as fine as 31.25 ns is possible.

4 Scope - Time Domain

Selective measurement of a channel with bandwidth (CBW) settable between 100 Hz and 32 MHz, and display of peak or RMS values versus time. Time spans of up to 24 h can be set. The measurement results are shown on a compressed time scale. By highest time resolution setting (32 ns) shortest single pulses even down to below ns length can be detected thanks to comprehensive trigger funtion and low noise figure.