G
Geodesy

Bits & Bites

Regional Reference Frames: Keeping Track of a Deforming Earth

August 28, 2026
Regional Reference Frames: Keeping Track of a Deforming Earth
Figure courtesy: Öykü Koç

You are observing the construction of a bridge that will be initiated on the two banks of a river simultaneously, in such a way that the works will eventually meet in the middle of the river. You wonder, how do they make sure that the construction on the two sides will stay aligned with the millimeter precision that this project requires? You are aware of previous constructions where small miscalc ...[Read More]

From Quasars to Coordinates: How VLBI Measures Earth’s Shape and Motion

June 26, 2026
From Quasars to Coordinates: How VLBI Measures Earth’s Shape and Motion
Figure courtesy: Öykü Koç

Imagine determining the position of a point on Earth with millimeter precision using radio signals from celestial objects billions of light-years away. This may sound like science fiction, but it is exactly what Very Long Baseline Interferometry (VLBI) allows scientists to do. What is VLBI? Long before satellites and digital maps, people looked to the sky and used celestial objects—most commonly t ...[Read More]

Listening to reflections: What GNSS signals can tell us about a changing environment

May 29, 2026
Listening to reflections: What GNSS signals can tell us about a changing environment
Figure courtesy: Öykü Koç

Global Navigation Satellite Systems (GNSS) are best known for positioning, navigation, and monitoring Earth surface motions with high precision (see two of our previous posts on GNSS here and here). But did you know that the same satellite signals can also provide information about snow, soil moisture, or sea level, without installing any additional instruments? This idea lies at the heart of GNSS ...[Read More]

Bits and Bites of Geodesy – Satellite Gravimetry: Studying Earth’s water cycle from space

February 27, 2026
Bits and Bites of Geodesy – Satellite Gravimetry: Studying Earth’s water cycle from space
Figure courtesy: Öykü Koç

During winter, mountains gain mass because of snow covering the peaks. In spring, the snow melts and flows downstream until it reaches the ocean or evaporates into the atmosphere to reach back on the surface as rain or snow. The global water cycle is very complex and essential for life on our planet. Did you know we can measure how the water is distributed by measuring its mass from space? How can ...[Read More]