What do we call the intentional degradation of GPS signals by the U.S. military?

The intentional degradation of GPS signals by the U.S. military is referred to as Selective Availability (SA). This was a technique used to introduce errors into the GPS signals accessible to civilian users, thereby enhancing the accuracy of GPS for military applications while preventing adversaries from having access to precise location data. By intentionally degrading the GPS signals for unencrypted civilian use, the military could maintain operational security and ensure that critical navigation capabilities were reserved for authorized users.

Selective Availability was discontinued in 2000, making civilian GPS signals significantly more accurate and reliable. This change allowed worldwide users to access GPS data with much higher precision and has led to the widespread use of GPS in various applications beyond military purposes, such as within mapping, agriculture, and navigation technologies.

The other options refer to different aspects related to GPS but do not pertain to intentional signal degradation. Multipath error involves inaccuracies that occur when GPS signals bounce off objects before reaching the receiver, DGPS (Differential GPS) improves GPS accuracy by using a network of fixed ground-based reference stations, and PDOP (Position Dilution of Precision) refers to a measure of the geometric configuration of the satellites used in GPS, affecting the overall accuracy.