SignalScope features a multi-channel FFT Analyzer, capable of displaying real-time magnitude spectra, with any of various data window types and FFT lengths. Audio input is typically sampled at a rate of 48 kHz, which enables a spectral bandwidth of nominally 24 kHz. The built-in accelerometer supports a bandwidth of approximately 50 Hz.
The available data window types include:
- Uniform (rectangular)
- Flat Top
- Hann (Hanning)
- Rife-Vincent 2
Frequency resolutions between 0.1 Hz and 50 Hz may be specified for audio input. Resolutions between 0.1 Hz and 10 Hz may be specified for the built-in accelerometer. Finer frequency resolutions yield longer FFT's.
A data cursor may be placed within the spectrum display with a single tap. You can move the data cursor by sliding your finger to the right or left inside the spectrum display. When the cursor is visible, spectrum information associated with the cursor is displayed in a small info view above the spectrum display. It is possible to zoom in or out on the spectrum display with a two-finger pinching gesture, and to pan the display, while zoomed in, with two fingers. A double-tap resets the display zoom and a second double tap turns off the data cursor. Cursor peak tracking can be cycled between max, min, and off with a triple tap.
Depending on the current auto-scaling selection, the vertical scale of the spectrum display may also be altered by a single-finger slide, or with a two-finger pinching gesture inside the vertical axis region (the region containing the vertical axis title and labels).