Very Long Baseline Interferometry (VLBI) is a microwave-based technique that evolved from radio astronomy in the early 1970s.

Nowadays, VLBI is a major space-geodetic technique, indispensable for geodesy.

VLBI delivers unique geodetic products that play indispensable roles for science and society.

VLBI uniquely contributes to the most precise and stable reference frames, which are fundamental for

numerous applications – from navigation to global change monitoring.

VLBI is the only operational technique to determine the Universal Time UT1 that reflects the Earth’s rotation behavior.

Precisely knowing this parameter is essential for navigation systems, such as ESA’s Galileo.

Bright radio sources located at the edge of the universe – billions of light-years from Earth – serve as

ultra-stable benchmarks that are observed by VLBI.