2022 NOAA Topobathy Lidar: Morro Bay, CA

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.

This lidar report provides accompanying information about the collection and processing of this lidar data set.

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.

Data for the Morro Bay 2022 project area were acquired by Quantum Spatial (NV5) using Riegl VQ-880-GII Topobathy Lidar systems. All derived LAS data is referenced to:

Horizontal Datum-NAD83(2011) epoch: 2010.00

Projection-UTM Zone 10N

Horizontal Units-meters

Vertical Datum-NAVD88 (Geoid12b)

Vertical Units-meters

This Morro Bay 2022 redelivery dataset encompasses 97 - 500m x 500m tiles in southern California.

Collected Lidar data were immediately processed by NV5 to a level that allowed QA/QC measures to determine if the sensor functioned properly and to assess the coverage of submerged topography. The initial files were inspected for sensor malfunctions and then passed through automated raster generation to develop an initial assessment of bathymetric coverage. NV5 reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points.

NV5 resolved kinematic corrections for aircraft position data in PosPac MMS 8.5 using aircraft GNSS and Applanix's proprietary PP-RTX solution. This was used to correct continuous onboard measurements of aircraft position recorded throughout the flight. A final smoothed best estimate trajectory (SBET) was developed, blending post-processed aircraft position with attitude data. Using the SBETs, sensor head position and attitude were calculated throughout the survey.

Following final SBET creation, NV5 used RiUnite 1.0.1 to calculate laser point positioning by associating SBET positions to each laser point return time. The speed of light and its direction of travel is changed or refracted when entering the water column from air. A refraction correction was applied to account for this difference by adjusting depth (distance traveled) and horizontal positioning (change of angle/direction) of all submerged points in the Lidar data. TerraSolid v19 and NV5's proprietary software LasMonkey were used to classify water surface points and derive water surface models. Separate models were created for each scanner of each collected swath to ensure temporal differences and wave or water surface height variations between flight lines were accurately accounted for when applying refraction correction to submerged data. These models, along with the Lidar points and the SBETs, were processed in LasMonkey's refraction tool to accurately adjust the positioning of bathymetric points. Using raster-based QC methods, output data were verified to ensure the refraction tool functioned properly.

Once all submerged points were refracted by flight line, data were exported to LAS 1.4 format and combined into 500 m x 500 m tiles. NV5 used custom algorithms in Terrascan v19 to classify the initial ground/submerged topography surface points. Data were further calibrated using StripAlign 2.1 based on classified hard surface areas of swath overlap. Relative accuracy was compared and verified through the use Delta-Z (DZ) orthos created using NV5's Las Product Creator. Absolute vertical accuracy of calibrated data were assessed using ground survey data and complete coverage was again verified.

After a final automated classification, NV5 performed manual editing to review all classification and improve the final Topobathymetric surface. NV5's LasMonkey software was used to update LAS header information, including all projection and coordinate reference system information. The final Lidar data are in LAS format 1.4 and point data record format 6.

The final classification scheme is:

1 - unclassified

1O - edge clip

2 - ground

7W - low noise

9 - NIR water surface

18W - high noise

40 - bathymetric bottom or submerged topography

41 - Green water surface

43 - Submerged object, not otherwise specified (For Morro Bay, oyster reefs have this classification, even though exposed at low tide)

45 - water column

The NOAA Office for Coastal Management (OCM) received 97 LAS files from NV5 Geospatial. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 10N NAD83(2011), meters coordinates and NAVD88 (Geoid12B) elevations in meters. The point classifications were: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 18 - High Noise, 40 - Bathymetric Point, 41 - Water Surface, 45 - Water Column. OCM processed all point classes to the Digital Coast Data Access Viewer (DAV).

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

1. Internal OCM scripts were run to check the number of points by classification and by flight ID and the gps, elevation, and intensity ranges.

2. Internal OCM scripts were run on the las files to:

a. Convert from NAVD88 (Geoid12B) elevations to ellipsoid elevations

b. Convert from UTM Zone 10N NAD83 (2011), meters coordinates to geographic coordinates

c. Assign the geokeys, to sort the data by gps time and zip the data to database and to the S3 Amazon bucket.

In February 2023, the NOAA Office for Coastal Management (OCM) received 3 LAS files from NV5 Geospatial. The files contained lidar elevation and intensity measurements and replace 3 existing files. The files are: MRR22_038, MRR22_046, and MRR22_055. These 3 files include class 43 points that are classified as "Submerged object, not otherwise specified (For Morro Bay, oyster reefs have this classification, even though exposed at low tide)." The data were in UTM Zone 10N NAD83(2011), meters coordinates and NAVD88 (Geoid12B) elevations in meters. The point classifications were: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 18 - High Noise, 40 - Bathymetric Point, 41 - Water Surface, 43 - Submerged Object, 45 - Water Column. OCM processed all point classes to the Digital Coast Data Access Viewer (DAV).

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

1. Internal OCM scripts were run to check the number of points by classification and by flight ID and the gps, elevation, and intensity ranges.

2. Internal OCM scripts were run on the las files to:

a. Convert from NAVD88 (Geoid12B) elevations to ellipsoid elevations

b. Convert from UTM Zone 10N NAD83 (2011), meters coordinates to geographic coordinates

c. Assign the geokeys, to sort the data by gps time and zip the data to database and to the S3 Amazon bucket.