In churches in western countries, they are in a sacred place. They should forbid any uncivilized actions, and cell phone ringtones will annoy others, which is very uncivilized. Therefore, in order to maintain a quiet atmosphere and maintain the spirit of the Holy Spirit, many churches install cell phone jammer in the church to block signals when necessary. As you can imagine, the phone suddenly rings while praying to God, which is a disaster. Therefore, interrupting cell phone frequency may be a good way to stay silent in a church.
Most mobile phone jammers can also interfere with GPS signals and can also be called mobile phone GPS directional interceptors; it may also be designed to interfere with control, but its main operating mode is almost certainly a directional GPS blocker. In other words, it will only generate noise on the GPS signal. Without a well-protected and well-oriented GPS antenna, the GPS signal will not be able to be distinguished, thus playing a role in intercepting the GPS signal.
According to Braasch, the RAIM function of a GPS device approved by the IFR method should issue a warning if the GPS signal location is inaccurate due to cell phone signal jammers or other issues: "RAIM is basically a form of failure detection. Please see All satellites, and check that they agree with each other, and if they do not, ignore them.