CEFAS24-146 RFQ for Light Detection and Ranging (LiDAR) surveys at Sizewell.

To support the delivery of the BEEMS Programme, Cefas have the requirement to work with a supplier to assess error margins around estimates of the ground elevation under dune and coastal vegetation at Sizewell-Minsmere.

Accurate, or slightly conservative, estimates of the beach and dune surface under vegetation are required to ensure that beach volumes (specifically Soft Coastal Defence Feature (SCDF) volumes) are not over-estimated which could otherwise result in delayed SCDF maintenance triggers and maintenance, and increased risks of SCDF buffer & Hard Coastal Defence Feature (HCDF) exposure.

The supplier is required to test the next generation of Light Detection and Ranging (LiDAR) sensors, which have more power and improved laser to penetrate further into the vegetation, against elevations from detailed ground truthing Global Navigation Satellite System (GNSS) and Red Green Blue (RGB) optical imagery.

Surveys are required to be undertaken when coastal vegetation is at its minima, average and maxima (c.

January, March/April and June).

The proposed work will include three LiDAR surveys, each with accompanying ground truth surveys, collected with a GNSS receiver rover (short occupation only, no tripod required).

Accuracy requirements for ground truthing measurements are to be within Root Mean Square Error (RMSE) ±3cm horizontal and ±4cm vertical, equivalent to a detailed survey performed under relative kinematic methodology as per RICS 'Use of GNSS in land surveying and mapping 3rd edition' standards.

Please see supporting documents contained within the bidder pack for details of the survey area, and minimum expected ground truthing points.

For full details download the Bidder Pack at https://defra-family.force.com/s/Welcome and search for CEFAS24-146 under opportunities.