Specifications

3.8.3 : Optional Parameters
Either base parameter set can be enhanced with up to three (3) additional
parameters. These are also tab-delimited and are appended to the base
parameter set in the following order:
SPL : Peak Sound Pressure Level (SPL dB)
Curv : Curvature measurement
Fit : Curvature fit error (RMS error in Hz)
The SPL parameter is valid only when using calibrated detectors like
the BAT AR125. Otherwise, it can only be considered as relative signal
strength measurement that may vary from detector to detector.
The Curvature measurement is a novel way to characterize the shape of
bat calls. This idea was described by Simon Jolly in the Australasian
Bat Society Newsletter in 1997. The basic premise is that bat calls can
me modeled by the equation:
frequency ~= time
P
where P is an integer value
SCAN’R employs this model, but enhances it to allow a fractional expo-
nent (P). SCAN’R also adopts a new convention to easily identify up-
ward curving and downward curving calls.
If the call is downward curving P is positive and:
frequency ~= time
P
where P is an fractional value
If the call is upward curving P is negative and:
frequency ~= time
1/(-P)
where P is an fractional value
Thus for any value of P, P and -P reflect the same basic shape, but P
curves downward while –P curves upward.