SCIENTIST SAYS / NGC MONTHLY SERIES / DECEMBER 2025

Prof. Martin Herold - In-situ and Remote Sensing expert

Wed 3 December 2025,  NGC Communication Team

Professor Martin Herold. Photo:  NGC Communication Team 

SCIENTIST SAYS – OUR MONTHLY INTERVIEW SERIES Meet Professor Martin Herold, Head of Remote Sensing and Geoinformation at GFZ Helmholtz Centre for Geosciences (GFZ) in Potsdam, Germany. Having expertise in large-area monitoring of land and forest dynamics integrating satellite and ground-based data streams from a scientific and user needs perspective, Martin is leading In-situ Supersites & Remote Sensing Integration (WP2*) team at NextGenCarbon. Martin explained to us how in-situ ground-based measurements can be enhanced and complement remote sensing data, and the benefits this can bring to larger area monitoring and applications.

What are in-situ, or ground-based measurements and supersites?

These are sites where we measure a series of variables using traditional and evolving ground- and near-sensing technologies with a particular focus on integrating them with satellite time series data. These sites are “data rich” and allow to demonstrate to potential also for large area, operational roll out.

How do you think WP2: In-situ Supersites and Remote Sensing Integration team will contribute to the advancement of in-situ observations?

The nice thing about the project is that we expand upon existing networks and sites (i.e. ICOS*) and expand with additional measurements to increase the detail and accuracy in monitoring. WP2 includes both the satellite and in-situ: in-situ meaning on the ground kind of measurements. Because of the size and the focus of the project, we really have the opportunity to take serious next steps in systematically improving the ground-based observations related to both carbon and water dynamics.

What improvements can be made in relation to ground-based observations and carbon and water dynamics?

For example, we systematically use terrestrial and drone-based laser scanning to measure structure and aboveground carbon stocks, and VOD (Vegetation Optical Depth) measurements that capture canopy water dynamics using GNSS (Global Navigation Satellite System) signals.

Because of the size and the focus of the project, we really have the opportunity to take serious next steps in systematically improve the ground-based observations related to both carbon and water dynamics.

What are the specific results and benefits that WP2 is aiming to produce?

Both the scale and setup of the ground measurements have a particular aim to more directly link with satellite data, i.e. provide on vegetation height, structure, biomass, LAI (Leaf Area Index) or canopy water characteristics. We will provide those as a benchmark dataset for the calibration and validation with available and upcoming satellite missions; incl. those from new mission concepts using space-based LIDAR (Light Detection and Ranging) and longer-wave Radar* sensors.

What impact do you think these results from WP2 will have on society?

So basically, the various in-situ ground sensing technologies and opportunities we are taking have the idea of monitoring large areas. So, we set up these things and use technologies that can also be scaled for larger areas, say to the whole ICOS network* to different parts of Europe, or integrated with satellite data to produce large area estimates. And I think this is an area where we could improve the quality of the data we deliver by integrating ground- and space-based data streams.

This includes delivering more near real-time data and tracking critical changes related to disturbances or water dynamics, that are really important, such as the impact of climate extremes.

Where can people interested in your area of research find you?

There are some information about some of the networks we work with like https://vodnet.netlify.app/ or https://strucnet.org/ or https://geo-trees.org/.

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*ICOS, Integrated Carbon Observation System

*The ICOS network is a European research network that monitors greenhouse gases.

*WP = Work package

*Radar = A radar is a system that uses radio waves to detect the presence, location, distance and speed of objects.