The 'SIG' option in the Cartesian coverage is enabled by switching it 'ON' (Checked). It will do 2 things:
The SIG function is enabled in the 'Cartesian Coverage' feature.
If the SIG switch is on, a SIG file is created in memory as part of the picture object.
As an example, you can perform a Cartesian Coverage on a picture in dBm and in microvolt on another picture. When you move the cursor, the text in the Status bar will display the signal of the active picture.
The following images display various values:
S-Units
dBm
uV
dB(uV/m)
When the signalmatrix function is on, a SIG file is created when you do as "Save Picture". This information is stored in the .SIG file with the picture. The SIG file is a binary file.
After loading a picture the signal information from the signal matrix is again available for analysis with the picture.