To feed an additional 2 billion people by 2030, water needs to be used more efficiently. Agriculture uses around 70 percent of all freshwater worldwide. It is estimated that water demand would grow by 45 percent by 2030 as increasingly affluent consumers demand higher value food. Farmers are challenged to produce “more crop per drop”.
MISTRALE sets up a service providing soil moisture maps and flooded area maps for improved monitoring of agricultural fields. These soil moisture maps help farmers to make more efficient decisions where and when to irrigate. MISTRALE also enables the monitoring of catchment areas and wetlands, providing water managers with information to optimize their activities.
To do so, MISTRALE will develop a prototype of a GNSS Reflectometry sensor integrated on a dedicated remotely piloted aircraft system (RPAS). The GNSS-R sensor measures the GNSS signals reflected by the ground and derives from these measurements the soil-water properties. As with other remote sensing techniques, observations in GNSS-R are based on the variability of the soil’s dielectric properties with the humidity of the terrain. Consequently the reflected signal's peak power can be related to soil moisture.
On demand of a farmer, or based on a predefined schedule, MISTRALE RPAS will be flown over the area of interest. During the flight, the direct and the reflected (both left and right hand side polarization) GNSS signals will be measured, pre-processed, and stored onboard the RPAS. Depending of the size of the field and the required resolution, the RPAS will be flown between 50 and 300 m with a speed range of 40-70 km/h. Once back on the ground the soil moisture maps of the covered area will be computed based on the collected data.
This constitutes an innovative and non-usual way of using the satellite signals. In this respect, the use of GALILEO signals, with its larger bandwidth and its different carriers, on top of GPS and GLONASS, will enable better accuracy of GNSS-R measurements.
MISTRALE is the perfect complement to COPERNICUS measurements and to in situ sensors. Indeed, satellite based earth observation provides a full picture of the global soil moisture situation on a very large areas, but with limited resolution and no flexibility on the data refresh rate. On the contrary, in situ sensors can provide almost continuous measurements but for their location only. MISTRALE will offer the possibility to offer on demand high-resolution soil moisture maps of a complete field or areas.
