The CT GIS Office has selected Dewberry Engineers, Inc. as the vendor that will be acquiring aerial imagery and LiDAR for the entire state as well as producing some requested derived data products.
Here is a summary of the deliverables agreed to by both OPM and Dewberry:
- Aerial 4-band digital orthoimagery.
- 3-inch resolution.
- Leaf-off capture in the spring of 2023 and 2026 respectively.
- True orthoimagery (nadir) over urban centers and tall bridges/overpasses.
- Elevation data captured using LiDAR (QL1)
- 15 points per square meter (ppsm) for the inland portions of the state and 20 ppsm in the coastal region as identified by OPM in consultation with the selection committee and GIS Advisory Council Imagery Acquisition Working Group.
- Point cloud will be classified to include the following classifications:
- 15 points per square meter (ppsm) for the inland portions of the state and 20 ppsm in the coastal region as identified by OPM in consultation with the selection committee and GIS Advisory Council Imagery Acquisition Working Group.
Table 7: LIDAR CLASSIFICATION SCHEMA | |
CLASS NUMBER (#) | DESCRIPTION |
Class 1 | Processed, but unclassified |
Class 2 | Bare-Earth Ground |
Class 3 | Low Vegetation |
Class 4 | Medium Vegetation |
Class 5 | High Vegetation |
Class 6 | Buildings |
Class 7 | Low Noise |
Class 9 | Water (points located within collected hydro breaklines) |
Class 17 | Bridge Deck |
Class 18 | High Noise |
Class 20 | Ignored Ground (typically breakline proximity) |
Class 21 | Snow (if present and identifiable) |
Class 22 | Temporal exclusion (typically non-favored data in intertidal zones) |
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- Bare Earth Digital Elevation Model at 0.5-meter resolution or better (hydro-flattened).
- LiDAR-Derived 1-Foot Contours.
- LiDAR-Derived Building Footprints for all structures larger than 100 ft2
- 3D Terrain Model with 3D Buildings (Level of Detail 2).
If you or your organization are interested in acquiring any buy-ups from Dewberry, please reach out to their point of contact for this project: Srinu Ratnala (sratnala@dewberry.com) to discuss. If you or your organization elect to purchase something, please keep the CT GIS Office in the loop in case we can be of assistance in any way.
The Dewberry team is currently ready to mobilize and is only waiting for the weather to clear up so the planes can get in the air. Additionally, I plan to provide periodic updates on this project as it progresses and significant milestones are achieved.