MLAT/WAM does not depend on satellite data and is a more autonomous and protected system capable of providing a high level of redundancy and verification of ADS-B 1090ES data. The EU reported
plans to create about 20 more WAM zones by 2020, as well as plans to install 30 systems at airports from 2018 to 2020.
Sweden, the UK, Japan, Austria, the USA, Australia, New Zealand, Namibia, Canada, Russia, and the Czech Republic are the countries where the MLAT/WAM projects have been implemented.
In some countries, for example, in Namibia or Sweden, national MLAT/WAM are deployed covering the entire state.
In conclusion, we note that secondary radars, as well as airfield survey locators, continue to operate. However, the global trend towards the introduction of more modern air navigation systems is obvious.