2013 USGS Lidar: Jefferson County, AL

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options.

Bulk download of data files in LAZ format, Alabama State Plane West, NAD83, US survey feet coordinates and NAVD88 (Geoid 12A) elevations in feet.

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

Link to the additional information available for this data set from the USGS. This information may include reports, tile index shapefiles, and hydro breaklines.

Link to the lidar report.

Entwine Point Tile (EPT) is a simple and flexible octree-based storage format for point cloud data. The data is organized in such a way that the data can be reasonably streamed over the internet, pulling only the points you need. EPT files can be queried to return a subset of the points that give you a representation of the area. As you zoom further in, you are requesting higher and higher densities. A dataset in EPT will contain a lot of files, however, the ept.json file describes all the rest. The EPT file can be used in Potree and QGIS to view the point cloud.

Link to view the point cloud (using the Entwine Point Tile (EPT) format) in the 3D Potree viewer.

The ABGPS, IMU, and raw Leica ALS70HP LiDAR data are integrated into the IPAS post processor software. The resultant file is in a LAS binary file format. The LAS file version 1.2 formats can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return#, intensity value, xyz, etc.). The resultant points are produced in the geodetic coordinates referenced to the WGS1984_UTM16N horizontal datum and Ellipsoid Height, Meters.

The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile any data if not complete. Subsequently the mission points are output using Leica's ALS Post Processor, initially with default values from Leica or the last mission calibrated for the system. The initial point generation for each mission calibration is verified within Terrascan using a distance colored point cloud to identify errors. If a calibration error greater than specification is observed within the mission, the roll, pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are output again and validated internally to ensure quality. Once validated each output mission is imported into the Geocue software package. Here a project level supplementary coverage check is carried out to ensure no data voids unreported by Field Operations are present.

Conversion from Geodetic coordinates WGS_1984 into NAD_1883_2011_UTM16N, NAVD88 (Geoid12A) Orthometric height, meters, was done using GeoCue.

The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters is applied as appropriate for the production of bare earth digital terrain models (dtms). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces. The LiDAR mass points were delivered in American Society for Photogrammetry and Remote Sensing LAS 1.2 format. The header file for each dataset is complete as define by the LAS 1.2 specification. The data was classified as follows: Class 1 = Unclassified. This class includes all non-ground classified points. Class 2 = Ground. Class 7 = Low Points. Class 9 = water. Class 10 - breakline proximity. Class 12 = Overlap.

Dataset copied to delivery drive, and content reviewed.

Original point clouds in LAS/LAZ format were restructured as Entwine Point Tiles and stored on Amazon Web Services. The data were re-projected horizontally to WGS84 Web Mercator (EPSG 3857) and the vertical units were converted to meters (NAVD88 GEOID12A).

References to the entwine point tiles and data reports were ingested into the Digital Coast Data Access Viewer. No changes to the data were made at this point. The Data Access Viewer will access the point cloud as it resides on AWS under the usgs-lidar-public container.

This is the EPT file being accessed:

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_AL_JeffersonCo_2013_LAS_2015/ept.json