dHz(decihertz)

A decihertz (dHz) is a unit of frequency measurement equal to one-tenth of a hertz (0.1 Hz). In the field of frequency, a hertz (Hz) is the unit of measurement for the number of cycles or oscillations a periodic signal or event undergoes in one second. A decihertz implies that there are 0.1 cycles or oscillations per second. It is a less common unit for expressing frequency, but it can be useful for describing very low-frequency phenomena or for scientific applications where precision is necessary.

µHz(microhertz)

In the field of frequency, µHz (microhertz) is a unit of measurement that represents a frequency of one millionth (1/1,000,000) of a hertz. Frequency is the number of occurrences of a repeating event per unit of time, typically represented using the unit "hertz" (Hz). One hertz is equal to one cycle or oscillation per second. A microhertz (µHz), therefore, represents an extremely low frequency where there is one cycle or oscillation per million seconds (1,000,000 seconds or roughly 11.6 days). This unit is used to describe extremely low-frequency signals or processes, such as certain astronomical or geophysical phenomena.