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Short Citation:
OCM Partners, 2023: 2017 USGS Lidar DEM: Upper Delta Plain, LA, https://www.fisheries.noaa.gov/inport/item/52969.

Item Identification

Title: 2017 USGS Lidar DEM: Upper Delta Plain, LA
Short Name: la2017_up_delta_pln_dem_m8568_metadata
Status: Completed
Publication Date: 2018-01-25
Abstract:

Product: These are Digital Elevation Model (DEM) data. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened Raster DEM.

Geographic Extent: Upper Delta Plain, Louisiana, covering approximately 3843 square miles.

Dataset Description: This Upper Delta Plain QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at an aggregate nominal pulse spacing (ANPS) of 0.7 meters (2ppsm). Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), Universal Transverse Mercator (zone 15 N), meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files, formatted to 4802 individual 1500 m x 1500 m tiles, as tiled Intensity Imagery, as tiled bare earth DEMs, and as tiled digital surface models; all tiled to the same 1500 m x 1500 m schema.

Ground Conditions: Lidar was collected in early 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Terrasurv, Inc. established a total of 63 ground control points that were used to calibrate the lidar to known ground locations established throughout the Upper Delta Plain, Louisiana project area. An additional 179 independent accuracy checkpoints, 101 Bare Ground/Low Grass landcovers (101 NVA points), 67 in Tall Weeds/Brush categories, and 11 in Woods category (78 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

The NOAA Office for Coastal Management (OCM) downloaded the LA_UpperDeltaPlain_2017 Digital Elevation Model (DEM) files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/OPR/ and processed the data to the Data Access Viewer (DAV) and https.

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEMs were created from, are also available. These data are available for custom download at the link provided in the URL section of this metadata record.

Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

Purpose:

The new elevation information derived from the lidar data will provide a more accurate elevation surface for CoNED development, including landscape modeling and projections, while providing needed elevation monitoring information for coastal restoration project planning and implementation.

Supplemental Information:

DEM Raster File Type = GeoTIFF

Bit Depth/Pixel Type = 32-bit float

Raster Cell Size = 1.0 Meters

Interpolation or Resampling Technique = Triangulated Irregular Network (TIN)

Network Required Vertical Accuracy = 19.6 cm NVA

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 > COASTAL PROCESSES > COASTAL ELEVATION
UNCONTROLLED
None DEM
None Digital Elevation Model
None Elevation Data
None Lidar
None Model
None Raster
None Remote Sensing

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > LOUISIANA
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE
UNCONTROLLED
Geographic Names Information System Upper Delta Plain
None U.S. Coastline

Instrument Keywords

Thesaurus Keyword
UNCONTROLLED
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
DEM > Digital Elevation Model
UNCONTROLLED
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: Fugro, USGS

Support Roles

Data Steward

CC ID: 759517
Date Effective From: 2018-07-02
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: 759518
Date Effective From: 2018-07-02
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: 759519
Date Effective From: 2018-07-02
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: 759520
Date Effective From: 2018-07-02
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: 759538
W° Bound: -91.53485
E° Bound: -89.51626
N° Bound: 30.50229
S° Bound: 29.457351

Extent Group 1 / Time Frame 1

CC ID: 759522
Time Frame Type: Discrete
Start: 2017-01-23

Extent Group 1 / Time Frame 2

CC ID: 759523
Time Frame Type: Discrete
Start: 2017-01-26

Extent Group 1 / Time Frame 3

CC ID: 759524
Time Frame Type: Discrete
Start: 2017-01-27

Extent Group 1 / Time Frame 4

CC ID: 759525
Time Frame Type: Discrete
Start: 2017-01-28

Extent Group 1 / Time Frame 5

CC ID: 759526
Time Frame Type: Discrete
Start: 2017-01-30

Extent Group 1 / Time Frame 6

CC ID: 759527
Time Frame Type: Discrete
Start: 2017-01-31

Extent Group 1 / Time Frame 7

CC ID: 759528
Time Frame Type: Discrete
Start: 2017-02-15

Extent Group 1 / Time Frame 8

CC ID: 759529
Time Frame Type: Discrete
Start: 2017-02-22

Extent Group 1 / Time Frame 9

CC ID: 759530
Time Frame Type: Discrete
Start: 2017-02-25

Extent Group 1 / Time Frame 10

CC ID: 759531
Time Frame Type: Discrete
Start: 2017-03-02

Extent Group 1 / Time Frame 11

CC ID: 759532
Time Frame Type: Discrete
Start: 2017-03-03

Extent Group 1 / Time Frame 12

CC ID: 759533
Time Frame Type: Discrete
Start: 2017-03-14

Extent Group 1 / Time Frame 13

CC ID: 759534
Time Frame Type: Discrete
Start: 2017-03-15

Extent Group 1 / Time Frame 14

CC ID: 759535
Time Frame Type: Discrete
Start: 2017-03-16

Extent Group 1 / Time Frame 15

CC ID: 759536
Time Frame Type: Discrete
Start: 2017-03-20

Extent Group 1 / Time Frame 16

CC ID: 759537
Time Frame Type: Discrete
Start: 2017-04-24

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and 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: 759539
Start Date: 2018-07-02
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8568
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2018-07-02 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, map projection, file format, etc. A new metadata will be produced to reflect your request using this record as a base.

Compression: Zip

Distribution 2

CC ID: 759540
Start Date: 2018-07-02
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/LA_UpperDeltaPlain_DEM_2017_8568
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2018-07-02 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in the original coordinate system.

URLs

URL 1

CC ID: 759512
URL: https://coast.noaa.gov/
Name: NOAA's Office for Coastal Management (OCM) website
URL Type:
Online Resource
File Resource Format: HTML
Description:

Information on the NOAA Office for Coastal Management (OCM)

URL 2

CC ID: 759513
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 3

CC ID: 759514
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/la2017_usgs_up_del_pln_m8564.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 4

CC ID: 759515
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Survey_Report.pdf
Name: Survey report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to the survey report.

URL 5

CC ID: 759669
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/breaklines/
URL Type:
Online Resource
Description:

Link to the breaklines.

URL 6

CC ID: 768815
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Collection_Report.pdf
Name: Collection report
URL Type:
Online Resource
Description:

Link to the collection report.

URL 7

CC ID: 768816
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Project_Report.pdf
Name: Project report
URL Type:
Online Resource
Description:

Link to the project report.

URL 8

CC ID: 768817
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8564
URL Type:
Online Resource
Description:

Link to custom download the lidar point data from which these raster Digital Elevation Model (DEM) data were created.

Technical Environment

Description:

ArcMap 10.3; Global Mapper 17; ERDAS Imagine 2016; Fugro proprietary software; Windows 7 64-bit Operating System

\\server\directory path\*.tif

22.4 GB

Data Quality

Vertical Positional Accuracy:

The project specifications require the accuracy (ACCz) of the derived DEM be calculated and reported. The required NVA of the DEM is: ≤ 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSEz of 10 cm in the “open terrain” and/or “Urban” land cover categories; the NVA was tested with 101 checkpoints. The required Vegetated Vertical Accuracy (VVA) of the DEM is: ≤ 29.4 cm at a 95th percentile level, derived according to ASPRS Guidelines, Vertical Accuracy for Reporting LiDAR Data, i.e. based on the 95th percentile error in Vegetated land cover categories combined (Tall Grass, Brush, Forested Areas); the VVA was tested with 78 checkpoints. The checkpoints were independent and not used in the calibration or post processing of the lidar point cloud data. The surveyed checkpoints were distributed throughout the project area.

Tested 0.108 meters NVA at a 95% confidence level derived according to NSSDA. The NVA of the DEM was calculated using 101 independent checkpoints located in Low Grass/Bare Ground land cover classes. Tested 0.195 meters VVA at a 95th percentile level derived according to ASPRS Guidelines, Vertical Accuracy Reporting for LiDAR Data. The VVA of the DEM was calculated using 78 independent checkpoints located in Crops/Agriculture/Brush and Woods land cover classes.

Completeness Report:

The DEM raster files cover the entire project delivery boundary. The pixels that fall outside the project delivery boundary are set to Void with a unique “NODATA” value. The value is identified in the file headers. There are no void pixels inside the project boundary. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The bare earth surface is of good quality and passes Vertical Accuracy requirements.

Conceptual Consistency:

Compliance with the accuracy standard was ensured by the collection of ground control and the establishment of GPS base stations in the project area. The following checks were performed: 1) The lidar data accuracy was validated by performing a full boresight adjustment and then checking it against the ground control prior to generating a digital terrain model (DTM) or other products. 2) Lidar elevation data was validated through an inspection of edge matching and visual inspection for quality (artifact removal). The following software was used for the validation: 1) RiProcess 1.8.3, RiWorld 5.0.2, RiAnalyze 6.2, RiServer 1.99.5; and 2) Fugro proprietary software; 20170515.

Lineage

Sources

Upper Delta Plain, Louisiana Lidar Aerial Acquisition

CC ID: 759503
Contact Name: Fugro
Publish Date: 2017-04-26
Source Contribution:

Fugro collected Riegl-derived lidar over the Upper Delta Plain, Louisiana AOI with 0.7 meters ANPS. Data was collected when environmental conditions meet the criteria specified. To be specific, the following conditions existed prior to launch of the aircraft: 1) Water levels for either Grand Isle, LA or Shell Beach, LA were below -0.10 meters (mean sea level), for flight lines that were considered tidal, 2) Passage of a moderate to strong high-pressure system generating northerly winds in excess of 5 knots, 3) Cloud and fog-free between the aircraft and ground, 4) Snow free, 5) No unusual flooding or inundation, and 6) Leaf off. The collection for the Upper Delta Plain, Louisiana AOI was accomplished on January 23, 26, 27, 28, 30, and 31; February 15, 22, and 25; March 2, 3, 14, 15, 16, and 20; and April 24, 2017. The collection was performed using Riegl LMS-Q680i and Riegl LMS-Q780 lidar systems, serial numbers 165, 961, and 216.

Upper Delta Plain, Louisiana Lidar Report of Survey

CC ID: 759504
Contact Name: Terrasurv, Inc.
Publish Date: 2017-04-06
Extent Type: Range
Extent Start Date/Time: 2017-02-20
Extent End Date/Time: 2017-03-22
Source Contribution:

Under Fugro’s direction, all surveying activities were performed by Fugro's approved ID/IQ subcontractor Terrasurv, Inc. A total of 63 ground control points to support the lidar collection, along with 101 NVA and 78 VVA checkpoints were collected. The National Spatial Reference System (NSRS) was used to provide control for the network. A Virtual Reference System (VRS) was used to survey each of the lidar control points. GULFNet is a network of Continuously Operating Reference Stations (CORS) network operated by the Louisiana Spatial Reference Center which is tightly aligned with the CORS of the National Spatial Reference System (NSRS). Using this methodology and VRS network was crucial to being able to obtain accurate heights due to known subsidence issues with the passive (i.e. ground monumented stations) NSRS marks in the area. Many of the GULFNet stations are also part of the National CORS Network. The horizontal datum was the North American Datum of 1983 – NAD83 (2011), epoch 2010.0. The vertical datum was the North American Vertical Datum of 1988 (NAVD88), realized with GEOID12B.

Process Steps

Process Step 1

CC ID: 759505
Description:

Flight status was communicated during data collection. All acquired lidar data went through a preliminary review to assure that complete coverage had been obtained and that there were no gaps between flight lines before the flight crew left the project site. Once back in the office, the data was run through a complete iteration of processing to ensure that it is complete, uncorrupted, and that the entire project area has been covered without gaps between flight lines. There are essentially three steps to this processing: 1) GPS/IMU Processing - Airborne GPS and IMU data was processed using the airport GPS base station data. The following GPS base stations were utilized: Fugro (016), CORS (MOON), and CORS (SJHS). 2) Raw Lidar Data Processing - Technicians processed the raw data to LAS format flight lines with full resolution output before performing QC. A starting configuration file is used in this process, which contains the latest calibration parameters for the sensor. The technicians also generated flight line trajectories for each of the flight lines during this process. 3) Verification of Coverage and Data Quality - Technicians checked trajectory files to ensure completeness of acquisition for the flight lines, calibration lines, and cross flight lines. The intensity images were generated for the entire lift at the required 0.7 meter ANPS. Visual checks of the intensity images against the project boundary were performed to ensure full coverage to the 100 meter buffer beyond the project boundary. The intensity histogram was analyzed to ensure the quality of the intensity values. The technician also thoroughly reviewed the data for any gaps in project area. The technician generated a sample TIN surface to ensure no anomalies were present in the data. Turbulence was inspected for each flight line; if any adverse quality issues were discovered, the flight line was rejected and re-flown. The technician also evaluated the achieved post spacing against project specified 0.7 meter ANPS as well as making sure there is no clustering in point distribution.

Process Date/Time: 2017-04-26 00:00:00

Process Step 2

CC ID: 759506
Description:

The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Fugro proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas within the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze the matching between flight line overlaps for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was ≤ 6 cm within individual swaths (smooth surface repeatability) and ≤ 8 cm RMSD within swath overlap (between adjacent swaths) with a maximum difference of ± 16 cm. 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of RMSEZ (non-vegetated) ≤ 10 cm, NVA ≤ 19.6 cm 95% Confidence Level was met.

Process Date/Time: 2017-05-15 00:00:00

Process Step 3

CC ID: 759507
Description:

Once boresighting was complete for the project, the project was first set up for automatic classification. The lidar data was cut to production tiles. The low noise points, high noise points and ground points were classified automatically in this process. Fugro utilized commercial software, as well as proprietary, in-house developed software for automatic filtering. The parameters used in the process were customized for each terrain type to obtain optimum results. Once the automated filtering was completed, the files were run through a visual inspection to ensure that the filtering was not too aggressive or not aggressive enough. In cases where the filtering was too aggressive and important terrain were filtered out, the data was either run through a different filter within local area or was corrected during the manual filtering process. Bridge deck points were classified as well during the interactive editing process. Interactive editing was completed in visualization software that provides manual and automatic point classification tools. Fugro utilized commercial and proprietary software for this process. All manually inspected tiles went through a peer review to ensure proper editing and consistency. After the manual editing and peer review, all tiles went through another final automated classification routine. This process ensures only the required classifications are used in the final product (all points classified into any temporary classes during manual editing will be re-classified into the project specified classifications). Once manual inspection, QC and final autofilter is complete for the lidar tiles, the LAS data was packaged to the project specified tiling scheme, clipped to project boundary including the 100 meter buffer and formatted to LAS v1.4. It was also re-projected to UTM Zone 15 north; NAD83 (2011), meters; NAVD88 (GEOID12B), meters. The file header was formatted to meet the project specification with File Source ID assigned. This Classified Point Cloud product was used for the generation of derived products. This product was delivered in fully compliant LAS v1.4, Point Record Format 6 with Adjusted Standard GPS Time at a precision sufficient to allow unique timestamps for each pulse. Correct and properly formatted georeference information as Open Geospatial Consortium (OGC) well known text (WKT) was assigned in all LAS file headers. Each tile has unique File Source ID assigned. The Point Source ID matches to the flight line ID in the flight trajectory files. Intensity values are included for each point, normalized to 16-bit. The following classifications are included: Class 1 – Processed, but unclassified; Class 2 – Bare earth ground; Class 3 – Low Vegetation (3 meters or less); Class 7 – Low Noise; Class 9 – Water; Class 10 – Ignored Ground; Class 17 – Bridge Decks; and Class 18 – High Noise. The classified point cloud data was delivered in tiles without overlap using the project tiling scheme.

Process Date/Time: 2018-01-25 00:00:00

Process Step 4

CC ID: 759508
Description:

Upon the completion of lidar point cloud product creation, First Return points were used for intensity image generation automatically. The software considers points from neighboring tiles while creating the images for seamless edge matching. The initial intensity images were generated at 1.0 meter resolution in 16bit TIFF format. They were then converted to 8bit format. Georeferencing information was assigned to all images. The technician QC’ed the final intensity images before delivery. The intensity images were delivered in GeoTIFF with TFW format.

Process Date/Time: 2017-10-01 00:00:00

Process Step 5

CC ID: 759509
Description:

Hydro linework is produced by heads-up digitizing using classified lidar datasets. Additionally, products created from lidar including intensity images, shaded-relief TIN surfaces, and contours are used. Hydrographic features were collected as separate feature classes: 1) Inland Ponds and Lakes approximately 2-acre or greater surface area (Lakes) and 2) Inland Streams and Rivers of 100 feet nominal width (Rivers). Additionally, all breaklines used to enforce a logical terrain surface below a bridge were delivered as a separate shapefile. After initial collection, features were combined into working regions based on watershed sub-basins. Linework was then checked for the following topological and attribution rules: 1) Lines must be attributed with the correct feature code and 2) Lake and stream banklines must form closed polygons. Hydro features were collected as vector linework using lidar and its derived products listed above. This linework is initially 2D, meaning that it does not have elevation values assigned to individual line vertices. Vertex elevation values were assigned using a distance weighted distribution of lidar points closest to each vertex. This is similar to draping the 2D linework to a surface modeled from the lidar points. After the initial ‘drape’, the linework elevation values were further adjusted based on the following rules: 1) Lake feature vertices were re-assigned (flattened) to lowest draped vertex value and 2) Double stream bankline vertices were re-assigned based on the vertices of the closest adjusted double stream connector line. Fugro proprietary software was used to create profiles to ensure bank to bank flatness, monotonicity check, and lake flatness. The hydro breaklines were delivered as polygons in Esri ArcGIS version 10.3 geodatabase format.

Process Date/Time: 2018-01-30 00:00:00

Process Step 6

CC ID: 759510
Description:

The bare earth DEM was generated using the lidar bare earth points and 3D hydro breaklines to a resolution of 1.0 meter. Where needed, supplemental breaklines were collected and used in DEM generation under the bridges to ensure a logical terrain surface below a bridge. This was delivered as a separate shapefile. The bare earth points that fell within 1*NPS along the hydro breaklines (points in class 10) were excluded from the DEM generation process. This is analogous to the removal of mass points for the same reason in a traditional photogrammetrically compiled DTM. This process was done in batch using proprietary software. The technicians then used Fugro proprietary software for the production of the lidar-derived hydro flattened bare earth DEM surface in initial grid format at 1.0 meter GSD. Water bodies (inland ponds and lakes), inland streams and rivers, and island holes were hydro flattened within the DEM. Hydro flattening was applied to all water impoundments, natural or man-made, that are larger than approximately 2 acres in area and to all streams that are nominally wider than 100 feet. This process was done in batch. Once the initial, hydro flattened bare earth DEM was generated, the technicians checked the tiles to ensure that the grid spacing met specifications. The technicians also checked the surface to ensure proper hydro flattening. The entire data set was checked for complete project coverage. Once the data was checked, the tiles were then converted to industry-standard, GIS-compatible, 32-bit floating point raster format (LZW compressed 32-bit GeoTIFFs). Georeference information is included in the raster files. Void areas (i.e., areas outside the project boundary but within the tiling scheme) are coded using a unique “NODATA” value.

Process Date/Time: 2018-01-25 00:00:00

Process Step 7

CC ID: 759667
Description:

The NOAA Office for Coastal Management (OCM) downloaded 4802 LA_UpperDeltaPlain_2017 Digital Elevation Model (DEM) files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/OPR/. The data were in UTM Zone 15 North coordinates and NAVD88 (Geoid12B) elevations in meters. The bare earth raster files were at a 1 meter grid spacing.

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

1. Copied the files to https

Process Date/Time: 2018-07-02 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 52969
GUID: gov.noaa.nmfs.inport:52969
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2018-07-02 13:24+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2018-08-23
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2018-08-23
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2019-08-23