HELiPOD in use for agriculture Braunschweig helicopter towed probe measures the health of plants

The HELiPOD helicopter towed probe from Technische Universität Braunschweig is currently being used on a farm in Italy. There, it is participating in a large-scale measurement campaign by the European Space Agency (ESA). The aim is to use air measurements to record the condition of vegetation, such as signs of drought or heat stress in plants. The data obtained will help to respond to climatic changes at an early stage and to target agricultural measures more effectively.

Field measurements in the truest sense of the word – the helicopter takes off and lands on a stubble field, and the HELiPOD is transported there using large agricultural equipment. The ESA measurement campaign is using new sensors and comparing them with tried-and-tested methods: the new sensors detect chlorophyll fluorescence, which varies depending on the condition of the plants.

In future, it will be possible to observe the health of plants from satellites – whether they are healthy or stressed, for example due to drought, heat or nutrient deficiency.

The researchers are using various systems: direct measurements on the ground to record the real conditions in tomato, corn and clover fields; drones flying at low altitude over individual fields; a research aircraft at higher altitude – and the HELiPOD in between. The first measurements were taken in May 2025, when the plants were still younger and the environmental conditions less hot and dry.

JB Hyperspectral Devices, the company that developed the special sensors, is organising the large-scale campaign together with scientific groups from across Europe and is supporting the evaluation of the fluorescence data.

“The current measurements are an important part of the validation preparations for the European Space Agency’s Fluorescence Explorer (FLEX) satellite mission,” explains Dr. Dirk Schuettemeyer from ESA.

“HELiPOD is very flexible and therefore ideally suited for these measurements,” says Professor Astrid Lampert from the Institute of Flight Guidance at TU Braunschweig. “We fly over the fields several times while the other teams are also taking measurements there. In addition to fluorescence, we measure other atmospheric variables – such as temperature, wind, methane and ozone – which can help us to better understand the processes in the atmosphere.”

The working conditions are particularly challenging, but exciting: the HELiPOD was transported in a container, which also serves as a workplace for preparing flights and backing up data in the Mediterranean heat of 34 degrees Celsius in the shade – surrounded by a curious herd of dairy cows, which created a very special atmosphere.

ESA’s FLEX mission is expected to provide new insights into the photosynthesis of vegetation from 2026 onwards. The aim of the satellite measurements is to identify the health status of plants and provide them with more targeted support.