Not much is known about the HFHigh Frequency (3-30 MHz) Monster signal other than its properties. It is an OQPSK signal with a baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. rate of 48k or 24k. Due to natural fading on HFHigh Frequency (3-30 MHz) it is almost never seen at full strength with the natural PSKPhase-Shift Keying rounded amplitude shape. There is usually two of these signals present on HFHigh Frequency (3-30 MHz), one lower frequency than the other.
TDoA suggests that the signal is being transmitted outside of Chicago. Due to being near Chicago it is speculated that the signal may be used for high frequency trading via radio for lower latency.