Project deliverable Open Access

WWV/H Characterization Signal

Kristina Collins

Project member(s)
Matthew Deutch; Dean Okayama; Dean Takamatsu; William Yates; Glenn Nelson; Jim Spicer; Chris Fujita; Nathaniel Frissell; Phil Karn; John Gibbons; Dave Swartz
Research group(s)
David Kazdan; Ethan Miller; Philip J. Erickson; William Liles
Mike Lombardi

A signal designed to characterize the signals at stations WWV and WWVH. This signal was designed by members of the WWV/H Scientific Modulation Working Group for the test signal block at Minute 8 (WWV) and 44 (WWVH). 

Files in this upload:

  • WWV_Test_Signal_Generator.m: MATLAB script to synthesize signal. 
  • voiceintro.wav: A voice recording at the beginning of the signal, which states: "What follows is a scientific modulation test. For more information, visit"
  • test.csv: A .CSV of the test signal to support use with an arbitrary waveform generator.
  • test.wav: A playable WAV file of the signal.
  • testsignal.png: Time domain plot.

The signal test.wav consists of the following segments:

  • 10 second voice announcement. 
  • Gaussian white noise (2 seconds). 
  • One second blank time. 
  • Phase-coherent 2, 3, 4, 5 kHz sine waves that drop down by 3 dB 9 times, 10 seconds total. 
  • One second blank time. 
  • An eight-second sequence consisting of linear up-chirps and down-chirps, generated with long is 5 kHz over 1 second (TBW = 5,000), short is 5 kHz over 0.05 seconds (TBW = 250).  To wit: 3 short up, 3 short down, .5 seconds blank, 3 long up, 3 long down. 100 ms between chirps and at the end of each sub-sequence. 
  • 2 seconds blank time.
  • A one-cycle burst at 2.5 kHz frequency, for time domain measurement, repeated 5 times over the course of 1 second; then the same for 5 kHz.
  • One second blank time. 
  • Repeated 2 seconds of Gaussian white noise for synchronization. Same sequence.
  • 3 seconds blank time.


Update, 26 October 2021: A new file, test_without_voice.csv, has been added. This signal can be produced by commenting out lines 123-126 in the MATLAB code. 
NB: Do not open the .csv files in Excel before uploading them to the arbitrary waveform generator, or they will become unusable. Instead, upload them directly without opening them in Excel. 

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