ESVI
ESVI shows the spatial variability of fresh biomass on cropland over the season within one scale. The values range from 0 – 100 and correlate quite well with optical NDVI and other biomass indices.
SAR measures structure and humidity of the surface. The signal can be transformed in an index that represents fresh biomass.
The ESVI can be used for decision making in precision farming or crop monitoring for crop insurance or disaster management.
The map product can be delivered for single crop-types on field level or over all crop-types on regional level.
Color Composite
The color composite is purely derived from single date Sentinel-1 SAR data.
It gives a high contrast and shows different zones within single plots.
This map product is easy to perceive due to its natural color coding.
It is the ideal map product for farm managers, crop insurance underwriters and investors to understand what is going on the farms.
SWI
SWI (SAR water index)
The map product shows the moisture content in the vegetation and topsoil.
The data were tested against the NDWI (Gao) and correlate very well with this optical index.
The product is suitable for large-scale drought monitoring. It reliably indicates a deficit in precipitation.
It is suitable for use in irrigation management.
EVO
EVO (Evolution) is a color composite of three consecutive ESVI datasets.
The datasets are arranged in such a way that black or dark areas represent either water surfaces or bare-soil condition.
Forest areas appear in gray to white.
Green color indicates an increase. Dark green stands for low-level growth and light green for high-level growth.
In purple we see a reduction. It also applies that light purple represents a reduction at a high level and dark purple at a low level.
GCB
GCB (Gradual Change of Biomass)
The map product is based on ESVI and shows the change between two consecutive datasets.
The values are based on 100. Accordingly, a value of 70 is a reduction of 30 ESVI units.
A decrease during the ripening process or through harvesting is marked with red color. An increase in biomass is indicated in green color.
The map product directly shows the change in biomass.
Yield prediction
For companies in Germany, Ukraine and Argentina, we were able to make yield forecasts with a deviation of less than 10% from the actual yield.
We achieve the best results at the end of the growth phase, i.e. around 2 months before harvest. We only use the ESVI for the prognosis and do not need any other data such as weather or soil data. To train the model, we received historical yield data from the companies over several years.
The data helps the companies with harvest and storage logistics.
They can support crop insurance companies in calculating premiums, e.g. for index insurance schemes.
They provide valuable forecasts for the commodity market and for monitoring by national authorities.
LAI
LAI (Leaf Area Index)
The LAI is a leaf surface index. It was calibrated based on the ESVI with in-situ data. It is the overall LAI.
This means that all parts of the plant are taken into account, including yellowed parts of the plant if the plant is already in the maturity phase.
The LAI makes it possible to carry out yield modeling with regards to the phenology.
The map product is so far available for Hungary, Slovakia and Argentina.
LAI calibration
Time series comparison of the in-situ measurements and the calibrated LAI.
We found excellent correlations across different cultures.