Data Services Update – January 2018

There’s quite a lot that is new with our Data Services; what’s on offer, and how the data are licensed. You can sign up for a free account to download free Sentinel-1 and Sentinel-2 satellite imagery (and other, satellite-derived products) or sign up for a Premium account to do much more. You can access the data portal here.

Our Data Services products are capable of delivering multiple insights
Benefits of our Free account
  • Download readily available imagery from the Sentinel-1 and Sentinel-2 satellites
  • Access satellite-derived products that reveal information about our environment including habitats, soil, fire risk, agriculture, wetlands and forests.

Data available from Free accounts:

  • Seasonal Sentinel-1 (radar) imagery:
    • Summer 2016 image
    • Autumn 2016 image
    • Winter 2016 image
    • Spring 2017 image
  • Annual Sentinel-2 (optical) imagery and derived products:
    • 2016 ‘True Colour’/Red Green Blue (RGB) image
    • 2016 Normalised Difference Vegetation Index (NDVI) image
    • 2016 Enhanced Vegetation Index (EVI) image
    • 2016 Nitrogen Reflectance Index (NRI) image
    • Optimised Soil Adjusted Vegetation Index (OSAVI) image
Benefits of our Premium account:
  • Search our satellite image catalogue for the dates you need
  • Upload or draw your own areas of interest
  • Select the satellite-derived products you want (NDVI, EVI, NRI etc.)
  • Download only the areas you need
  • ‘Mask’ out cloud using our innovative cloud masking algorithm
What are the ‘satellite derived products?’
  • ‘True Colour’ Image/Red Green Blue (RGB) – The colours in a ‘true colour’ image appear as they would to a human. Suitable for visualisation purposes and observing change.
  • ‘Science Ready’ Image (Red Green Blue + NIR) – A multispectral image that provides information about the reflectance of blue, green, red and near-infrared light. Suitable for visualising changes in plant health, producing indices and classification.
  • Normalised Difference Vegetation Index (NDVI) – A measure of vegetation productivity (measure of ‘greenness’). Bright areas correspond to healthy, productive vegetation. Bare ground and urban areas will appear dark.
  • Enhanced Vegetation Index (EVI) – Similar to NDVI, EVI is used in areas of dense canopy where the large amounts of chlorophyll can affect the suitability of NDVI. EVI helps to correct for soil background signals and atmospheric influences.
  • Optimised Soil Adjusted Vegetation Index (OSAVI) – In areas where vegetation is sparse and soil is visible, OSAVI can be used to assess the abundance and vigour of vegetation. It is similar to NDVI, however it compensates for the effects of soil reflectance.
  • Plant Senescence Reflectance Index (PSRI) – An increase in PSRI indicates increased canopy stress, the onset of canopy senescence and plant fruit ripening. Applications include vegetation health monitoring, plant physiological stress detection plus crop production and yield analysis.
  • Nitrogen Reflectance Index (NRI) – Predicts plant nitrogen status. Can be used to estimate plant parameters and yield potential.
  • Modified Normalised Difference Water Index (MNDWI) – Using MNDWI is one of the most popular methods for water body mapping. It overcomes the shortcomings of NDWI by using shortwave infrared to replace near infra-red used in NDWI. In the last few decades, it has been widely applied to produce water body maps at different scales.
Our existing Sentinel-1 products are as follows:
  • Backscatter – A measure of the strength of the radar signal (measured in units of Sigma 0). Band 1 (VV) shows surface scattering; a rougher surface or urban areas with lots of right-angled structures generates higher VV backscatter. Band 2 (VH) relates to volume scattering; randomly oriented volumes, such as forests, generate higher VH backscatter than flat surfaces such as bare soil.
  • Backscatter with ratio band – The basic backscatter product with an additional ratio band. The ratio band helps visualise the product in an RGB composite, and also provides a measure of vegetation density. The ratio correlates well with biomass similar to optical indices such as NDVI NB: Backscatter products can also be produced on a decibel (dB) scale. This is useful for visualisation as you can see more detail in vegetation, but should be avoided for analytical purposes.

If you want to know more about interpreting our Sentinel-1 imagery check out our video here.