The new DEM data is now available for download, we are working to resolve issues with the Hillshade data, and Contours will be next on the list, followed by services! See details below on extent for the new data!
All LiDAR-related data currently available on the Vermont Open GeoData portal will be unavailable starting 12pm Friday July 1, 2016 through the weekend while updated data is being migrated to the portal. These updates include:
New LiDAR Data Available:
1. 2013 Rutland/Grand Isle data “collection” which includes the Mad River Valley (see map here): 0.7m resolution, Quality Level 2 (QL2).
2. A pre-release portion of the 0.7m Quality Level 2 (QL2) 2014 “Eastern VT” data “collection” which includes a portion of Georgia and stretches south along the lake into Charlotte in Chittenden County (see map here).
Changes to Existing Data:
1. Updated naming convention to all LiDAR related data. E.g., “Elevation_DEM1m1020_2005.img” is now “Elevation_DEM1M2005_1020.img”.
a. Digital Elevation Model (DEM) data now reflects its “hydro treatment”, e.g., DEM = “pure” DEM; DEMHF = “Hydro-flattened” DEM; DEMHE = “Hydro-enforced” DEM; see USGS’s “Hydro Treatments of LiDAR Derived DEMs” powerpoint for details.
2. All downloadable data layers are in their original, vendor-delivered tiling structure, re-projected to VT State Plane Coordinate System NAD83 meters, Zunits meters and the Erdas Imagine format. This primarily affected the following collections:
a. 2008 “Lower” Missisquoi – Reimported to original 1.6m, “hydro-flattened” DEM format;
b. 2010 “Upper” Missisquoi (a.k.a. “Rock River”) – Reimported to original 1.6m, “hydro-flattened” DEM format;
c. 2012 Bennington County – Reimported to original 2m, “pure” DEM format;
3. Only DEMs and contours (DEM/DEMHE/DEMHF) are provided in tiled format. Other derivatives are in single mosaic file format only.
a. When contour data was part of the original vendor delivery they are in the same tile index structure as the DEMs.
b. When contour data was not part of the original vendor delivery and created by VCGI in 2013/2014 they are in the “Ortho9” tile index.
4. All primary (DEMs) and secondary derivatives (ASPECT, DSM, HILSHD, nDSM & SLOPE) are available in a single, mosaic file format covering the full “collection” extent.
Changes to Metadata:
- All LiDAR metadata files have been updated to latest EGC format (May 2016).
- For original vendor metadata see “All VT LiDAR on an External drive” main page for all project level metadata in a central location (these are original vendor metadata for LAS data).