2009 USACE NCMP Topobathy Lidar: Panama City Beach, FL

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, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. They will be in an orthometric datum.

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.

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.

Link to custom download, from the Data Access Viewer (DAV), the raster Digital Elevation Model (DEM) data that were created from this lidar data set.

This graphic displays the footprint for this lidar data set.

These data were collected using the CHARTS system. It is owned by the Naval Oceanographic Office and operated through contract. The system collects topographic lidar data at 9 kHz, bathymetric lidar data at 1 kHz and RGB imagery at 1Hz. A CASI-1500 hyperspectral line scanner is integrated with the system as well. Aircraft position, velocity and acceleration information are collected through a combination of Novatel and POS A/V 410 equipment. All raw data streams are transferred to the office for downloading and processing in SHOALS GCS software. Aircraft position data are processed using POSPac software and the results are combined with the lidar data to produce 3-D positions for each lidar shot. Upon inspection and QA/QC in the software packages Fledermaus and PFM_ABE, anomalous data are flagged as invalid. PFM_ABE's chartsLAS module then converts all valid data from ellipsoid to orthometric heights based on the NGS' GEOID03 model and exports topographic data as a series of LAS files with a single file per flightline per 5km box.

The topographic flightline LAS files were imported into TerraMatch, a TerraSolid application that runs in Microstation. Upon import into TerraMatch, the data is converted from Geographic to UTM Zone16 North coordinates. Misalignment angles between individual flightlines were computed for both points classified as “ground” and points classified as “buildings”. These angles were utilized in an iterative process to adjust each flightline’s roll, pitch and heading bias values, in order to minimize mis-alignments between flight lines. Final horizontal alignments were QC’d by viewing cross-sections taken throughout the data coverage on features such as buildings and rooftops. Vertical adjustment to ground control, where available, or to prior survey surfaces, in the absence of ground control, was performed utilizing hard surfaces including roads and parking lots. Final QC was performed to verify all horizontal and vertical adjustments to the data.

The flightline LAS files are imported into the TerraScan V11 module within MicroStation V8.0. The resulting LAS files are thinned to eliminate duplicate points. A customized classification macro is used to distinguish ground points (2) and unclassified points (1). The classification results are QC'd and any misclassified points are manually edited. In areas of dense vegetation the bare ground points might be incorrectly classified due to the inability of the laser to penetrate the canopy and reach the bare ground. In these areas, JALBTCX defaults to the algorithm's "ground" surface instead of manually reclassifying those points. The points are exported to an ASCII file containing the following fields: longitude, latitude, elevation (orthometric), intensity, classification, mirror angle, time (GPS time), number of echos, and echo number. The ASCII file is converted to LAS with the txt2las code from LAStools (http://www.cs.unc.edu/~isenburg/lastools/).

Horizontal positions, provided in decimal degrees of latitude and longitude, are referenced to the North American Datum of 1983 (NAD83). Vertical positions are referenced to the NAD83 ellipsoid and provided in meters. The National Geodetic Survey's (NGS) GEOID03 model is used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88).

The NOAA Office for Coastal Management (OCM) received 13 las files for the Panama City Beach area from USACE JALBTCX. The lidar data had elevation and intensity measurements. The data were in geographic coordinates (NAD83) and NAVD88 (GEOID03) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2.

OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges.

2. Internal OCM scripts were run on the las files to convert the elevations from NAVD88 to ellipsoid using the GEOID03 model, to assign the geokeys, to sort the data by gps time and zip the data to database and to Amazon S3.