Editorial for the Metrologia Focus Issue on Length Metrology

This Focus Issue of Metrologia was instigated by the Consultative Committee for Length’s Working Group on Strategic Planning when it met online in 2020 during the COVID-19 pandemic. Submission of articles started closely thereafter and was closed in September 2022. Covering a wide range of topics, the issue shows that despite the Coronavirus pandemic disrupting laboratory work, length metrology researchers have continued to deliver cutting edge research. The revised definition of the metre and its Mise en Pratique , both published in 2019, have stimulated further research and opened additional opportunities for developing length metrology capabilities. Articles related to the new Mise en Pratique are included in the issue, together with a range of articles demonstrating the breadth and ingenuity of current leading edge research in length metrology. A final paper indicates how metrology, with length used as an example, may be enhanced by a transition to a digital framework for realising the SI.