Enabling the public sector to save money, innovate and make more effective policy decisions by using space technology and data

Case Study: Stevenson Astrosat – Coastal Sentry and RoofWatch

General Information

  • Provider: Stevenson Astrosat Ltd
  • Technology utilised: Earth observation (EO)
  • Thematic area: Natural Hazards
  • End user(s): Local Authorities


  • 2015

Stevenson Astrosat logoProject Background / Overview

The project’s goal was to assess the commercial and economic feasibility of a solution for monitoring events of interest to Local Authorities in the UK using satellite data – specifically synthetic aperture radar (SAR). Events considered included, but were not be limited to, coastal erosion monitoring, roof damage detection after severe weather conditions and building subsidence during / after flooding events.

Example of coastal erosion  Example of roof damage after severe weather conditions.

The project placed particular emphasis on identifying potential end users and addressing their needs. As such, considerations focused on how to deliver an economically viable solution and how to optimise the supply chain.

To achieve this a series of workshops were held with a range of potential end users. Their input was invaluable to define appropriate levels of reporting accuracy and costing. They included the British Geological Survey (BGS), New Forest District Council (NFDC) and Standing Conference on Problems Associated with the Coastline (SCOPAC) who all expressed interest in improving the efficiency and effectiveness of current methods for coastal erosion monitoring; and the Scottish Flood Forum who were interested in impact assessments of remote buildings during or after storm or flood events.

The solution devised focussed on coastal monitoring applications where there is more of an immediate appetite and potential scope. Test sites were selected in East Yorkshire and in the New Forest District Council area of responsibility. Satellite data was sourced from TerraSAR-X and Sentinel-1 SAR satellites. The extent of erosion was verified by in-situ derived data from the BGS and NFDC.

The findings were that the solution devised provided an acceptable level of accuracy to meet the end users’ requirements, and resulted in less data redundancy.

Lessons Learned

Satellite derived SAR data offers the potential to viably acquire data, with acceptable temporal and spatial resolutions, that meet the requirements of existing reporting output needs.

Costs and Benefits

Test site in East Yorkshire located along a 2km stretch of coastline at Aldburgh. Due to its geological make-up and exposure to the North Sea this area is particularly susceptible to erosion.This study found that the solution would be financially viable for stretches of coastline greater in length than approximately 4 to 5km, and / or where the site is inaccessible and therefore requires specialist involvement. In such cases the initial set-up costs would be offset by the potential savings made from replacing existing surveying techniques – making this solution viable.

Furthermore, it would be possible for neighbouring Local Authorities to pool their resources and expertise to capture imagery of larger stretches of coastline, thus reducing their financial outflows.

Aside from the financial gains this solution offers substantial improvements to workforce safety. Less time will need to be spent on site in potentially hazardous surroundings, and the high frequency of satellite passes over a specified location will capture data regardless of weather conditions.

Next Steps

For the coastal erosion application future work would focus on expanding the service to cover a significant part of the UK’s coastline, and collaborating with coastal groups, such as SCOPAC and NFDC, to further define the practical operational principles and output criteria of the solution. Once agreed a dynamic dashboard – the Coastal Sentry dashboard - would be issued to share the data with end users. This dashboard would build on from the existing prototype to fully meet the end users’ needs. The potential for exporting this service to other nations around the world who could benefit from this capability would also be explored.

Attention would also turn to applications beyond coastal erosion to determine the usefulness of the data and the feasibility of rolling this out.