2022 USF Topobathymetric Lidar: Tampa Bay, 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.

This graphic displays the footprint for this lidar data set.

Survey report from Fugro.

The data was collected using the RAMMS LiDAR system. It is owned by Fugro and operated through contract. The system collects bathymetric lidar data at 30 Hz lidar pulse and generates up to 900 beams per pulse. RGB imagery was collected with a PhaseOne iXM-50 digital camera. Aircraft position, velocity and acceleration information were collected through POS AV 510 v6 equipment. All raw data streams were transferred to the field office for downloading and processing in RAMMS Processing Module software. Aircraft position data were processed using POSPac software and the results were combined with the lidar data to produce 3D positions for each beam points. Upon QA/QC in the Terrasolid software suite, point cloud data was classified into bathytmetry, topography and other non-terrain classes. All valid topography are class 2; depths are class 40 and 43.

The data were received in LAS 1.4 format from the University of South Florida. The data generally appeared to follow the topobathy domain profile, but also contained undefined lidar classifications. The Class histogram for the dataset was:

Class Number and Point count:

0 378141361

1 19235839

2 117

7 4786920

8 1

9 6407

12 168653570

18 511160148

22 1204

30 218426

40 407816951

41 844187621

42 1607

45 168647432

This does not agree with the previous step's statement that all valid topography are class two. Examination of the data also revealed that class 7 and class 18 (low noise and high noise) are essentially flipped in the water areas, with low noise near the water surface and high noise below the sea floor. Class 12 appeared to be a subset of the points over terrestrial areas, but was clearly not a ground class. All points in classes 0, 1, 8, 12, 22, and 30 were recombined into class 1 and extracted into separate files. Automated processes to identify noise and ground points (lasnoise and lasground_new from LAStools) for the separated files. The files separated by class were re-merged after classification.

Points marked as withheld were dropped from the dataset. These were typically on noise points. Other classification flags may have limited validity. For example, the flag keypoints was found on many unclassified points.

For ingest into the Digital Coast Data Access Viewer, the points were converted to geographic coordinates and cloud optimized point cloud (COPC) format.

The final classification histogram is:

class count

1 434155871

2 131616712

7 4669842

9 6407

18 511145834

40 407816951

41 844187621

42 1607

45 168647432