Fc
Characteristic Frequency; the frequency (kHz) at the right-hand end of the portion of the call with the lowest absolute slope (the body).
Feeding buzz
A series of pulses where the bat is honing in on prey. Pulses are typically steeper, higher frequency and with smaller pulse interval
Fend
The frequency at the end of the pulse. In the case of ZC, the frequency of the last ZC dot of the pulse.
FFT
Fast Fourier Transform, see FFT window
FFT Window
Fast Fourier Transform (FFT) relating to the time and frequency resolutions. Changing the FFT Window will alter the horizontal and vertical rendering of full spectum data.
Fk
Frequency of the knee; frequency (kHz) of the junction (point of greatest change in slope) between the initial and pre-characteristic sections
FM
Frequency Modulated, see Frequency Modulated
FMax
The maximum frequency (kHz) of the pulse.
FMean
The mean frequency; which is a weighted mean, FMean = (N – 1)D/2d, where N is number of points counted in the display, D is the division ratio and d is the duration of the call.
FMin
The minimum frequency (kHz) of the pulse.