power calibration area (CD) (PCA)
On recordable compact discs(CD-R), there is a specified area for the calibration of the laser beam, the Power Calibration Area (PCA).
This PCA area is used when writing a compact disc to adjust the power of the laser to the CD-R. The Power Calibration Area (PCA), along with the Program Memory Area( PMA), is located near the inner track, before the header, the lead-in. The PCA area starts at -35 seconds, the PMA area at -13 seconds.