Short Citation:
Office for Coastal Management, 2021: 2019 NOAA Topobathy Lidar DEM (Interpolated): Morro Bay, CA, https://www.fisheries.noaa.gov/inport/item/57930.

Item Identification

Title: 2019 NOAA Topobathy Lidar DEM (Interpolated): Morro Bay, CA
Status: Completed
Creation Date: 2019-10-10
Abstract:

These data represent integrated lidar and sonar gridded surface data. Quantum Spatial, Inc. (QSI) collected the topobathymetric lidar using a Riegl VQ880GII system on May 22, 2019. Merkel and Associates collected sonar data to provide bathymetric surface modeling in areas lacking lidar coverage. The sonar was collected between June 17th-19th, 2019 using a SEA SWATHplus-H sonar system. QSI performed the lidar/sonar integration. The dataset includes topobathy data in a LAS 1.4 format file with the following classification:1-Unclassified, 1-O (Overlap bit) - Edge clip (geometrically unreliable points at the edge of flightline swaths), 2-Ground, 7-Noise, 9-NIR water surface, 20-Ignored ground and sonar (excluded for seamless model creation), 40-Bathymetric point, 41-Green laser water surface,and 45- Green laser water column in accordance with project specifications. Sonar data has been assigned a Point Source ID of 9 and a User Byte of 2. All other data is lidar-derived. The NOAA Morro Bay area of covers approximately 4,215 acres over Morro Bay, including the Morro Bay Estuary and roughly 3.6 miles of coastline. LAS files were compiled by 500 m x 500 m tiles.

An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. Classes 2 (ground), and 40 (submerged topography) were used to create the final DEMs. The full workflow used for this project is documented in the NOAA Morro Bay final report.

Interpolated DEM dataset-These DEMs represent a continuous surface with all void areas interpolated. No void layer was incorporated into this DEM and there are no areas of No Data, regardless of whether the LiDAR data fully penetrated to the submerged topography.

Purpose:

Data was collected to aid NOAA in assessing the channel morphology and topobathymetric surface of the study area to support the Morro Bay National Estuary Program in habitat restoration and management.

Supplemental Information:

An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. Classes 2 (ground), and 40 (submerged topography) were used to create the final DEMs. The full workflow used for this project is documented in the NOAA Morro Bay final report.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Topography > Terrain Elevation
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry > Coastal Bathymetry
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Coastal Processes > Coastal Elevation
ISO 19115 Topic Category Elevation
None Bathymetry
None beach
None DEM
None digital elevation model
None erosion
None laser
None lidar
None Sonar

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America
Global Change Master Directory (GCMD) Location Keywords Vertical Location > Land Surface
Global Change Master Directory (GCMD) Location Keywords Vertical Location > Seafloor
None Continent > North America > United States Of America > California
None Continent > North America > United States Of America > California > Morro Bay
None U.S. Coastline
None United States

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords Earth Remote Sensing Instruments > Active Remote Sensing > Profilers/Sounders > Lidar/Laser Sounders > LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords Aircraft > Aircraft

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: None Planned
Data Presentation Form: Model (digital)
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners

Data Set Credit: We request that you credit the National Oceanic and Atmospheric Administration (NOAA) when you use these data in a report, publication, or presentation., National Oceanic and Atmospheric Administration (NOAA), Office of Coastal Management

Support Roles

Data Steward

CC ID: 882420
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 882421
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 882422
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 882423
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 882437
W° Bound: -120.875211
E° Bound: -120.821145
N° Bound: 35.373531
S° Bound: 35.304796

Extent Group 1 / Time Frame 1

CC ID: 882436
Time Frame Type: Range
Start: 2019-05-22
End: 2019-06-19

Spatial Information

Spatial Representation

Representations Used

Grid: No
Vector: Yes
Text / Table: No
TIN: No
Stereo Model: No
Video: No

Reference Systems

Reference System 1

CC ID: 882455

Coordinate Reference System

CRS Type: Geographic 2D
EPSG Code: EPSG:6318
EPSG Name: NAD83(2011)
See Full Coordinate Reference System Information

Reference System 2

CC ID: 882456

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:6339
EPSG Name: NAD83(2011) / UTM zone 10N
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for custom downloads

Data Access Constraints:

None

Data Use Constraints:

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

Distribution Information

Distribution 1

CC ID: 882424
Start Date: 2019-10-09
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8893
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Customized Download
Description:

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.

File Type: Zip
Compression: Zip

Distribution 2

CC ID: 882425
Start Date: 2019-10-09
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/NOAA_MorroBay_Interpolate_8894/
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Bulk Download
Description:

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.

File Type: LAZ

URLs

URL 1

CC ID: 882426
URL: https://coast.noaa.gov/dataviewer/
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML
Description:

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.

URL 2

CC ID: 882427
URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8892/supplemental/Morro_Bay_Footprint_m8892.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 3

CC ID: 882454
URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8892/supplemental/NOAA_Morro_Bay_Topobathymetric_LiDAR_Sonar_Integration_Report_V2.pdf
Name: Project Report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to downloadable project report.

Technical Environment

Description:

OS Independent

Data Quality

Vertical Positional Accuracy:

The DEMs are derived from the source LiDAR and inherit the accuracy of the source data. The DEMs are created using controlled and tested methods to limit the amount of error introduced during DEM production so that any differences identified between the source LiDAR and final DEMs can be attributed to interpolation differences. DEMs are created by averaging several LiDAR points within each pixel which may result in slightly different elevation values at a given location when compared to the source LAS, which does not average several LiDAR points together but may interpolate (linearly) between two or three points to derive an elevation value.

Absolute accuracy was assessed using the Non-Vegetated Vertical Accuracy (NVA) checks. Survey checkpoints were evenly distributed throughout the project area as feasible. NVA compares known ground check point data that were withheld from the calibration and post-processing of the LiDAR point cloud to the triangulated surface generated by the unclassified LiDAR point cloud as well as the derived gridded bare earth DEM. NVA is a measure of the accuracy of LiDAR point data in open areas with level slope (less than 20°) where the LiDAR system has a high probability of measuring the ground surface and is evaluated at the 95% confidence interval (1.96*RMSE). In the Morro Bay area 20 survey checkpoints were used to assess the non-vegetated vertical accuracy. Project specifications require NVA meet 0.196 m accuracy at the 95% confidence interval. Specifications for this project also require that bathymetric accuracy meet the standard laid out in the National Coastal Mapping Strategy (NCMS) V1.0 for QL2b Bathy Lidar which was estimated to be 30cm at a 95% confidence level. In the Morro Bay area 81 survey checkpoints were used to assess the submerged topography accuracy. Submerged topography checkpoints usually occur in depths up to 1m.Qualitative value:0.052 0.101, Test that produced the value: Using NSSDA and FEMA methodology, the derived DEM non-vegetated vertical accuracy (NVA) at the 95% confidence level (called Accuracyz) was computed by the formula RMSEz x 1.9600. Morro Bay dataset tested 0.052 m vertical accuracy at 95% confidence level against the derived gridded bare earth DEM in open terrain using 20 ground check points, based on RMSEz (0.027 m) x 1.9600. Using NSSDA and FEMA methodology, bathymetric vertical accuracy at the 95% confidence level for submerged topography was computed by the formula RMSEz x 1.9600. Morro Bay dataset tested 0.101 m vertical accuracy at 95% confidence level against the classified points cloud using 81 submerged check points, based on RMSEz (0.052 m) x 1.9600.

Completeness Report:

Morro Bay DEM data covers 97 tiles (500 m x 500 m tiles).

Conceptual Consistency:

Not applicable

Data Management

Have Resources for Management of these Data Been Identified?: Yes
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown
Do these Data Comply with the Data Access Directive?: Yes
Actual or Planned Long-Term Data Archive Location: NCEI-CO
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to tape and to cloud storage.

Lineage

Sources

Processed Topobathy

CC ID: 885488
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial (QSI)

Raw Lidar

CC ID: 885486
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial (QSI)

Sonar Data

CC ID: 885487
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Merkel and Associates

Process Steps

Process Step 1

CC ID: 882432
Description:

Data for the NOAA Morro Bay project was acquired by Quantum Spatial (QSI) using a Riegl VQ-880GII Topobathy LiDAR system. Sonar data was collected by Merkel and Associates using a SEA SWATHplus-H sonar system.

QSI reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points. QSI creates an initial product call Quick Look Coverage Maps. These Quick Looks files are not fully processed data or final products. The collected LiDAR data is immediately processed in the field by QSI to a level that will allow QA\QC measures to determine if the sensor is functioning properly and assess the coverage of submerged topography. An initial SBET was created in POSPAC MMS 8.1 and used in RiProcess which applies pre-calibrated angular misalignment corrections of scanner position to extract the raw point cloud into geo-referenced LAS files. These files were inspected for sensor malfunctions and then passed through automated classification routines (TerraScan) to develop a rough topobathymetric ground model for an initial assessment of bathymetric coverage.

To correct the continuous onboard measurements of the aircraft position recorded throughout the missions, QSI concurrently conducted multiple static Global Navigation Satellite System (GNSS) ground surveys (1 Hz recording frequency) over established monuments located in or around the project area. After the airborne survey, the static GPS data were triangulated with nearby Continuously Operating Reference Stations (CORS) using the Online Positioning User Service (OPUS) for precise positioning. Multiple independent sessions over the same monument were processed to confirm antenna height measurements and to refine position accuracy. QSI then resolved kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. A final smoothed best estimate trajectory (SBET) was developed that blends post-processed aircraft position with attitude data. Sensor head position and attitude are calculated throughout the survey. The SBET data are used extensively for laser point processing. The software Trimble Business Center v.3.90, Blue Marble Geographic Calculator 2017, and PosPac MMS 8.1 SP3 are used for these processes.

Source: Raw Lidar

Process Step 2

CC ID: 882434
Description:

Next, QSI used RiProcess 1.8.5 to calculate laser point positioning of the Riegl VQ-880GII data by associating SBET positions to each laser point return time, scan angle, intensity, etc. A raw laser point cloud is created in Riegl data format and erroneous points are filtered. Data was exported to LAS 1.4 format and are combined into 500 m x 500 m tiles. Data was then further calibrated using TerraScan, TerraModeler, and TerraMatch and a refraction correction was applied to all sub-water surface returns using QSI proprietary LAS Monkey software. QSI used custom algorithms in TerraScan to create the initial ground/submerged topography surface. Relative accuracy of the green swaths was compared to overlapping and adjacent swaths and verified through the use Delta-Z (DZ) orthos created using QSI's DZ Ortho creator. Absolute vertical accuracy of the calibrated data was assessed using ground RTK survey data and complete coverage was again verified.

QSI then performed manual editing to review all classification and improve the final topobathymetric surface. A final bathymetric void shape was created after final editing and provided to Merkel and Associates to target for sonar data collection. The acquired sonar was then integrated into the LiDAR dataset to provide a seamless bathymetric model. As a general rule, in areas of overlap sonar data was prioritized in deeper areas of the channel while LiDAR data was prioritized in shallower areas of the channel including all areas not submerged during the LiDAR collection. As the lidar laser approaches the laser’s extinction point bathymetric surface profiles and point density degrade thus the prioritization of sonar data in these areas. Conversely side-scan sonar does better when water depths are greater than 1m as areas shallower than this are prone to increased noise making the lidar data more reliable in these areas.

Within the Morro Bay site there was one notable area of significant temporal change. The sand spit at the mouth of the bay displayed a difference as great as 5 meters from the lidar survey. Despite this area being collected at true ground during the lidar survey, the sonar data was used in this area being the most temporally recent data and collected at high tide with high confidence in the surface.

All data from either sensor that was not used in model creation is still preserved in the point cloud as Ignored Ground/Bathymetry (class 20). Please see Appendix B of the NOAA Morro Bay Report for more information regarding the sonar acquisition and processing.

Final topobathymetric DEMs were created at 1m pixel resolution using ground (class 2) and bathymetry (class 40).

Source: Processed Topobathy

Process Step 3

CC ID: 882433
Description:

Interpolated DEM dataset-These DEMs represent a continuous surface with all void areas interpolated. No void layer was incorporated into this DEM and there are no areas of No Data, regardless of whether the LiDAR data fully penetrated to the submerged topography.

Source: Processed Topobathy

Process Step 4

CC ID: 885489
Description:

The Office for Coastal Management received the DEM files in geotiff format and processed them to the Data Access Viewer (DAV).

Process Date/Time: 2019-10-14 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2019 NOAA Topobathy Lidar DEM (Voids): Morro Bay, CA

Clipped DEM (with Voids)

Data Set (DS) Cross Reference 2019 NOAA Topobathy Lidar: Morro Bay, CA

Point Cloud

Catalog Details

Catalog Item ID: 57930
Metadata Record Created By: Blake Waring
Metadata Record Created: 2019-10-09 14:17+0000
Metadata Record Last Modified By: Brianna Key
Metadata Record Last Modified: 2020-12-11 16:02+0000
Metadata Record Published: 2019-10-10
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2020-10-10