Tenders Are Invited For Architectural, Construction, Engineering And Inspection Services – Phase 4 Of The Monitoring Strategy: Carrying Out A Topographic Acquisition By Airborne Lidar And Very High Resolution Coastal Orthophotography From The Bay Of Mont-Saint-Michel To The Belgian Border

Architectural, Construction, Engineering And Inspection Services – Phase 4 Of The Monitoring Strategy: Carrying Out A Topographic Acquisition By Airborne Lidar And Very High Resolution Coastal Orthophotography From The Bay Of Mont-Saint-Michel To The Belgian Border. The Contract Involves Carrying Out A Topographic Acquisition By Airborne Lidar And Very High Resolution Coastal Orthophotography, On The Coastline Of The Bay Of Mont-Saint-Michel, Pointe De Cancale Up To The Belgian Border At Bray-Dunes. The Objective Is To Constitute A Homogeneous, Precise And Lasting Base Of Topographical And Imaging Data Allowing Morphological And Diachronic Monitoring Of The Coastline. The Right-Of-Way Includes The Open Foreshore And Extends At Least Up To 1.5 Km Inland, With Extension To Coastal Units, Low-Lying Areas, Wetlands, Estuaries And Hydraulic Systems Functionally Linked To The Coastline. Lidar Acquisition Must Guarantee An Absolute Precision Better Than 10 Cm At 2Σ On Bare Ground, A Relative Precision Less Than 5 Cm And A Density Greater Than 8 Points/M² Of Usable Points For The Restitution Of The Terrain, Excluding Overlapping Zones. The Flight Strategy Must Preserve Morphological Shapes And Breaks, In Particular Cliffs, Dunes, Dikes, Embankments And Structures. Acquisitions Of The Foreshore Will Primarily Be Carried Out During Spring Tides With A Coefficient ≥ 90, In Windows Defined Between February And April 2027, By Seeking Low-Water Conditions Maximizing The Emerged Surface Area. Their Organization Must Integrate Tide Times And Levels, The Propagation Of The Tidal Wave, The Weather, Aeronautical Constraints And Lighting Conditions. The Aerial Photography Will Include The Four Channels Red, Green, Blue And Near Infrared, With A Native Resolution On The Ground Of 5 Cm. The Coverage Will Be At Least 80% Longitudinal And 40% Lateral, Increased To 60% In Complex Or High Relief Sectors. Deliverables Will Include Raw And Las/Laz Classified Lidar Clouds, Sol And Sursol Extractions, Dems And Dsms At Several Resolutions, Source Shots, Rgbi Orthophotography, Aerotriangulation And Calibration Data, As Well As Control And Traceability Data. The Orthophotos Will Also Be Organized Into A Four-Band Esri Rgbi Mosaic Dataset, Enabling Rgb And Irc Renderings, Complemented By Two Tpkx Rgb And Irc Tile Packages. All Source Data, Intermediate Data, Metadata And Control Reports Must Be Delivered In A Structured, Reproducible, Portable And Directly Usable Manner In The Project Owners Gis. The Holder Is Subject To An Obligation Of Results And Must Ensure Quality Controls, Correction Of Non-Conformities, Necessary Repurchase And Consistency Of Products With Previous Campaigns When Stable Reference Data Are Available.