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 hamsci.org/wwv." 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 https://www.mathworks.com/help/signal/ref/chirp.html: 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.