The VH/VV Sentinel-1 cross ratio highlights volume scattering and can be used to infer structural information about a landscape and provide insights into vegetation water content (Vreugdenhil et al., 2018). Computing the ratio helps to reduce measurement geometry, topography and calibration effects which may be present in the separate Sentinel-1 VH and VV polarisation bands (Meyer, 2019). This ratio can be used to monitor vegetation structure and growth and has been shown to correspond to NDVI for certain crops (Vreugdenhil et al., 2020).

The VH/VV cross ratio is calculated using the Defra and Joint Nature Conservation Committee (JNCC) VH (band 2) and VV (band 1) ARD bands. Prior to completing the VH/VV calculation, the VV and VH polarisations are converted from decibels (as they are provided in the Defra and JNCC Sentinel-1 ARD) to a linear scale.

Data are provided in EPSG: 27700 OSGB36 / British National Grid, with a pixel size of 10m, and data is pixel-aligned to the source ARD file. No-data pixels are set to a value of -9999. Pixels with values of 50 or higher, or -50 or lower, were assigned the no-data value.

These data have been created by the Joint Nature Conservation Committee (JNCC) as part of the “Earth observation-based habitat change detection” project. This project is funded by the Department for Environment, Food and Rural Affairs (Defra) as part of the Natural Capital and Ecosystem Assessment (NCEA) programme. The project seeks to facilitate the effective uptake and use of Earth Observation data by producing data and tools for investigating and detecting parcel-level change in habitats and habitat condition.

VH/VV files have been generated for Sentinel-1A ascending orbit granules covering England and Scotland for the period from 2015 to 2025.

Contains modified Copernicus Sentinel data 2015-2025