What does the Y axis represent?
The Y axis when using a sound card is a 16 bit number made from averaging a number of peak buffer samples from the sound card. See the sound card data source help for how you can affect the buffer size. The number represents the relative signal strength of the audio as detected by this method. To determine an absolute value for the Y axis it should be calibrated using an external calibrator appropriate for the type of observation you are using. For example an RF noise source can be used at the input of radio and the radio used to drive the sound card. The Y axis can then be charted to the dBm or equivalent noise temperature. To make the translation of the Y numbers directly on the chart you can develop a function and apply it in real time with the Equation feature of the Pro version.
