The P/Y code is the precision code of the GPS system, which is used for military applications and has a resolution that is one power of ten higher than the C/A code (Coarse/Acquisition) used for civilian purposes.
The positioning accuracy of the P/Y code, which stands for Precision Code, is less than 2 meters. The P/Y code is derived from the reference frequency of the atomic frequency standard of 10.23 MHz and is transmitted on both GPS frequencies. To reduce interference, transmission is in spread-band technology with a bandwidth of 20 MHz. Since the classic P code was mainly used for military applications, it is encrypted in a tamper- proof manner and transmitted exclusively as encrypted P/Y code.