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Short Citation:
OCM Partners, 2023: 2015 USGS Lidar: Eastern Shore VA, https://www.fisheries.noaa.gov/inport/item/50784.

Item Identification

Title: 2015 USGS Lidar: Eastern Shore VA
Short Name: va2015_eastern_shore_m8445_metadata
Status: Completed
Publication Date: 2016-01
Abstract:

Leading Edge Geomatics (LEG) collected 994 square miles in the Virginia counties of Accomack and Northampton. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 0-Never Classified, 1-Unclassified, 2-Ground (bare earth points identified as Model Key Points are flagged with the Model Key Point bit), 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridge Decks, 18-High Noise. Because the Eastern Shore Virginia LiDAR project includes data from the Sandy Topobathy project, there are also topobathy point classifications. They are: 23 - Sensor noise, 24 - Refracted sensor noise, 25 - Water column, 26 - Bathymetric bottom, 27 - Water Surface. Classes 28, 29, and 151 were also included, but after discussion with Dewberry, were determined to be noise classes that should be disregarded. NOAA Office for Coastal Management processed all classifications of points to the Digital Coast Data Access Viewer (DAV), but have made the topobathy noise points unavailable. Classes available from the DAV are: 1, 2, 7, 9, 10, 17, 18, 25, 26, 27.

Dewberry produced 3D breaklines and combined these with the final LiDAR data to produce seamless hydro flattened DEMs for the project area. The data was formatted according to the VBMP tile naming convention with each tile covering an area of 5,000 feet by 5,000 ft. A total of 1375 LAS tiles and 1310 DEM tiles were produced for the entire project.

The NOAA Office for Coastal Management (OCM) downloaded this lidar data from the USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/NED/LPC/projects/USGS_LPC_VA_Eastern_ShoreBAA_2015_LAS_2017/ and processed the data to be available on the Digital Coast Data Access Viewer (DAV).

In addition to these lidar point data, the breakline data are also available. These data are are available for download at the link provided in the URL section of this metadata record. 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 purpose of this LiDAR data was to produce high accuracy 3D elevation products, including tiled LiDAR in LAS 1.4 format, 3D breaklines, and 2.5 foot cell size hydro flattened Digital Elevation Models (DEMs). All products follow and comply with USGS Lidar Base Specification Version 1.2.

Notes:

Loaded by FGDC Metadata Uploader, batch 10315, 12-15-2017 09:16

The following FGDC sections are not currently supported in InPort, but were preserved and will be included in the FGDC export:

- Spatial Reference Information (FGDC:spref),

- Spatial Data Organization Information (FGDC:spdoinfo)

Supplemental Information:

A complete description of this dataset is available in the Final Project Report that was submitted to the U.S. Geological Survey.

The following are the USGS lidar fields in JSON:

{

"lidar" : {

"ldrinfo" : {

"ldrspec" : "USGS-NGP Lidar Base Specification V1.2",

"ldrsens" : "Riegl 680i",

"ldrmaxnr" : "7",

"ldrnps" : "0.66",

"ldrdens" : "2.25",

"ldranps" : "0.53",

"ldradens" : "3.45",

"ldrfltht" : "1000",

"ldrfltsp" : "100",

"ldrscana" : "60",

"ldrscanr" : "78",

"ldrpulsr" : "200",

"ldrpulsd" : "5",

"ldrpulsw" : "0.89",

"ldrwavel" : "1064",

"ldrmpia" : "0",

"ldrbmdiv" : "5.0",

"ldrswatw" : "1155",

"ldrswato" : "50",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.118",

"rawnvan" : "59",

"clsnva" : "0.122",

"clsnvan" : "61",

"clsvva" : "0.177",

"clsvvan" : "52"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld points were identified in these files using the standard LAS Withheld bit",

"lasolap" : "Swath overage points were identified in these files using the standard LAS overlap bit",

"lasintr" : "16",

"lasclass" : {

"clascode" : "0",

"clasitem" : "Calibrated, never classified"

},

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth, ground (includes model key point bit for points identified as Model Key Point)"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored ground due to breakline proximity"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High noise"

}

}

}}

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
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Bare earth

Temporal Keywords

Thesaurus Keyword
UNCONTROLLED
None 2015
None April

Spatial Keywords

Thesaurus Keyword
UNCONTROLLED
Global Change Master Directory (GCMD) Location Keywords Continent>North America>United States>Virginia

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: None Planned
Data Presentation Form: Point Cloud (Digital)
Entity Attribute Overview:

LiDAR points in LAS 1.4 format

Entity Attribute Detail Citation:

none

Distribution Liability:

This data was produced for the U.S. Geological Survey according to specific project requirements. This information is provided "as is". Further documentation of this data can be obtained by contacting: USGS, 1400 Independence Road, Rolla, MO 65401. Telephone (573) 308-3810.

Any conclusions drawn from the analysis of this information are not the responsibility of Leading Edge Geomatics, Dewberry & Davis the US Geological Survey, the NOAA Office for Coastal Management, or its partners.

Data Set Credit: Dewberry & Davis, Leading Edge Geomatics, USGS

Support Roles

Data Steward

CC ID: 704548
Date Effective From: 2017-12-15
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: 704549
Date Effective From: 2017-12-15
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: 704550
Date Effective From: 2017-12-15
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

Originator

CC ID: 704551
Date Effective From: 2017-12-15
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: 704552
Date Effective From: 2017-12-15
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: 1140639
W° Bound: -76.093949
E° Bound: -75.2271
N° Bound: 38.064707
S° Bound: 37.062181

Extent Group 1 / Time Frame 1

CC ID: 1140638
Time Frame Type: Range
Start: 2015-04-11
End: 2015-04-24

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8445

Data Access Constraints:

None

Data Use Constraints:

This data was produced for the U.S. Geological Survey according to specific project requirements. This information is provided "as is". Further documentation of this data can be obtained by contacting: USGS, 1400 Independence Road, Rolla, MO 65401. Telephone (573)308-3810.

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

Distribution Information

Distribution 1

CC ID: 704557
Start Date: 2017-12-15
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8445
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2017-12-15 - Present)
Compression: Zip

Distribution 2

CC ID: 704558
Start Date: 2017-12-15
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8445/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2017-12-15 - Present)

URLs

URL 1

CC ID: 704559
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8445/supplemental/va2015_usgs_eastern_shore_m8445.kmz
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic displays the footprint for this lidar data set.

URL 2

CC ID: 704560
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8445/supplemental/va2015_usgs_eastern_shore_m8445_project_report.pdf
URL Type:
Online Resource
File Resource Format: pdf
Description:

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

URL 3

CC ID: 704561
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8445/breaklines/index.html
URL Type:
Other
Description:

Link to download the breakline data

URL 4

CC ID: 704562
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource
Description:

Link to the Data Access Viewer (DAV) where elevation, imagery, and land cover data are available for custom download.

URL 5

CC ID: 704563
URL: https://coast.noaa.gov/dataregistry
URL Type:
Online Resource
Description:

Link to the Digital Coast Data where many types of coastal data are available for download.

URL 6

CC ID: 704564
URL: https://coast.noaa.gov/
URL Type:
Online Resource
Description:

Link to the NOAA Office for Coastal Management (OCM) homepage.

URL 7

CC ID: 713533
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8445/supplemental/va2015_usgs_eastern_shore_m8445_survey_report.pdf
Description:

This survey report provides accompanying information about the collection and processing of the check point data.

Technical Environment

Description:

Microsoft Windows 7 Enterprise Service Pack 1; ESRI ArcCatalog 10.3

Data Quality

Horizontal Positional Accuracy:

Only checkpoints photo-identifiable in the intensity imagery can be used to test the horizontal accuracy of the LiDAR. Photo-identifiable checkpoints in intensity imagery typically include checkpoints located at the ends of paint stripes on concrete or asphalt surfaces or checkpoints located at 90 degree corners of different reflectivity, e.g. a sidewalk corner adjoining a grass surface. The xy coordinates of checkpoints, as defined in the intensity imagery, are compared to surveyed xy coordinates for each photo-identifiable checkpoint. These differences are used to compute the tested horizontal accuracy of the LiDAR. As not all projects contain photo-identifiable checkpoints, the horizontal accuracy of the LiDAR cannot always be tested.

Lidar vendors calibrate their lidar systems during installation of the system and then again for every project acquired. Typical calibrations include cross flights that capture features from multiple directions that allow adjustments to be performed so that the captured features are consistent between all swaths and cross flights from all directions. Dewberry tested the horizontal accuracy of the LiDAR by comparing photo-identifiable survey checkpoints to the LiDAR Intensity Imagery. As only seventeen (17) checkpoints were photo-identifiable, the results are not statistically significant enough to report as a final tested value but the results of this testing are shown below. Using NSSDA methodology (endorsed by the ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014)), horizontal accuracy at the 95% confidence level (called ACCURACYr) is computed by the formula RMSEr * 1.7308 or RMSExy * 2.448. Actual positional accuracy of this dataset was found to be RMSEx = 0.83 ft (25 cm) and RMSEy = 0.91 ft (28 cm) which equates to +/- 2.13 ft (65 cm) at 95% confidence level.

Vertical Positional Accuracy:

The vertical accuracy of the LiDAR was tested by Dewberry with 113 independent survey checkpoints. The survey checkpoints are evenly distributed throughout the project area and are located in areas of non-vegetated terrain (61 checkpoints), including bare earth, open terrain, and urban terrain, and vegetated terrain (52 checkpoints), including forest, brush, tall weeds, crops, and high grass. The vertical accuracy is tested by comparing survey checkpoints to a triangulated irregular network (TIN) that is created from the LiDAR ground points. Checkpoints are always compared to interpolated surfaces created from the LiDAR point cloud because it is unlikely that a survey checkpoint will be located at the location of a discrete LiDAR point. All checkpoints located in non-vegetated terrain were used to compute the Non-vegetated Vertical Accuracy (NVA). Project specifications required a NVA of 0.64 ft (19.6 cm) at the 95% confidence level based on RMSEz (0.33 ft/10 cm) x 1.9600. All checkpoints located in vegetated terrain were used to compute the Vegetated Vertical Accuracy (VVA). Project specifications required a VVA of 0.96 ft (29.4 cm) based on the 95th percentile.

This LiDAR dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 0.33 ft (10 cm) RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz =0.21 ft (6.40 cm), equating to +/- 0.41 ft (12.5 cm) at 95% confidence level.

Completeness Report:

A visual qualitative assessment was performed to ensure data completeness and bare earth data cleanliness. No void or missing data and data passes vertical accuracy specifications.

Conceptual Consistency:

Data covers the entire tile scheme provided for the project area.

Lineage

Process Steps

Process Step 1

CC ID: 1140633
Description:

Data for the Eastern Shores Virginia QL2 LiDAR project was acquired by Leading Edge Geomatics (LEG).

The project area included approximately 994 contiguous square miles or 2574.45 square kilometers for the counties of Accomack and Northampton in Virginia. LiDAR sensor data were collected with the Riegl 680i LiDAR system. The data was delivered in the State Plane coordinate system, feet, Virginia South, horizontal datum NAD83, vertical datum NAVD88, Geoid 12a. Deliverables for the project included a raw (unclassified) calibrated LiDAR point cloud, survey control, and a final acquisition/calibration report.

The calibration process considered all errors inherent with the equipment including errors in GPS, IMU, and sensor specific parameters. Adjustments were made to achieve a flight line to flight line data match (relative calibration) and subsequently adjusted to control for absolute accuracy. Process steps to achieve this are as follows:

Rigorous LiDAR calibration: all sources of error such as the sensor's ranging and torsion parameters, atmospheric variables, GPS conditions, and IMU offsets were analyzed and removed to the highest level possible. This method addresses all errors, both vertical and horizontal in nature. Ranging, atmospheric variables, and GPS conditions affect the vertical position of the surface, whereas IMU offsets and torsion parameters affect the data horizontally. The horizontal accuracy is proven through repeatability: when the position of features remains constant no matter what direction the plane was flying and no matter where the feature is positioned within the swath, relative horizontal accuracy is achieved.

Absolute horizontal accuracy is achieved through the use of differential GPS with base lines shorter than 25 miles. The base station is set at a temporary monument that is 'tied-in' to the CORS network. The same position is used for every lift, ensuring that any errors in its position will affect all data equally and can therefore be removed equally.

Vertical accuracy is achieved through the adjustment to ground control survey points within the finished product. Although the base station has absolute vertical accuracy, adjustments to sensor parameters introduces vertical error that must be normalized in the final (mean) adjustment.

A copy of the final calibrated swaths are maintained in LAS format 1.2 for production utilizing Terrascan software. A second, identical version of final calibrated swaths are converted from v1.2 to v1.4 using GeoCue software. The withheld and overlap bits are set and all headers, appropriate point data records, and variable length records, including spatial reference information, are updated in GeoCue software and then verified using proprietary Dewberry tools.

Process Date/Time: 2015-04-01 00:00:00

Process Step 2

CC ID: 1140634
Description:

Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All LiDAR related processes begin by importing the data into the GeoCue task management software. The swath data is tiled according to project specifications (5,000 ft x 5,000 ft). Dewberry extended the client provided boundary where tiles had ground to include thirty four extra tiles. The tiled data is then opened in Terrascan where Dewberry classifies edge of flight line points that may be geometrically unusable to a separate class. These points are separated from the main point cloud so that they are not used in the ground algorithms. Dewberry then uses proprietary ground classification routines to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. As part of the ground routine, low noise points are classified to class 7 and high noise points are classified to class 18. Once the ground routine has been completed, bridge decks are classified to class 17 using bridge breaklines compiled by Dewberry. A manual quality control routine is then performed using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review is performed on all tiles and a supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification and bridge deck corrections are completed, the dataset is processed through a water classification routine that utilizes breaklines compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points that are within 1x NPS or less of the hydrographic features are moved to class 10, an ignored ground due to breakline proximity. Next, an intelligently thinned ground classification identified model key points and are flagged with the Model Key Point bit. Overage points are then identified in Terrascan and GeoCue is used to set the overlap bit for the overage points and the withheld bit is set on the withheld points previously identified in Terrascan before the ground classification routine was performed. A final QC is performed on the data. The LAS files are then converted from v1.2 to v1.4 using GeoCue software. At this time, all headers, appropriate point data records, and variable length records, including spatial reference information, are updated in GeoCue software and then verified using proprietary Dewberry tools.

The data was classified as follows:

Class 1 = Unclassified. This class includes vegetation, buildings, noise etc.

Class 2 = Ground (bare earth points identified as Model Key Points are flagged with the Model Key Point bit)

Class 7 = Low Noise

Class 9 = Water

Class 10 = Ignored Ground due to breakline proximity

Class 17 = Bridge Decks

Class 18 = High Noise

The LAS header information was verified to contain the following:

Class (Integer)

Adjusted GPS Time (0.0001 seconds)

Easting (0.003 m)

Northing (0.003 m)

Elevation (0.003 m)

Echo Number (Integer)

Echo (Integer)

Intensity (16 bit integer)

Flight Line (Integer)

Scan Angle (degree)

Process Date/Time: 2015-09-01 00:00:00

Process Step 3

CC ID: 1140635
Description:

Existing lidar data acquired and processed as part of the NOAA Sandy Supplemental project were re-processed and combined with the LEG data to supplement/complete data coverage along the eastern portion of this project

Process Date/Time: 2015-09-01 00:00:00

Process Step 4

CC ID: 1140636
Description:

The NOAA Office for Coastal Management (OCM) downloaded 1375 las files from the USGS rockyftp site. The files contained elevation and intensity measurements for the eastern shore of Virginia. The data were in VA State Plane South coordinates and NAVD88 (Geoid12A) elevations in survey feet. The data were classified as: 1-Unclassified, 2-Ground (bare earth points identified as Model Key Points are flagged with the Model Key Point bit), 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridge Decks, 18-High Noise. Because the Eastern Shore Virginia LiDAR project included data from the Sandy Topobathy project, there were also topobathy point classifications. They were: 23 - Sensor noise, 24 - Refracted sensor noise, 25 - Water column, 26 - Bathymetric bottom, 27 - Water Surface. Classes 28, 29, and 151 were also included, but after discussion with Dewberry, were determined to be noise classes that should be disregarded. NOAA Office for Coastal Management processed all classifications of points to the Digital Coast Data Access Viewer (DAV), but made the topobathy noise points unavailable. Classes available on the DAV are: 1, 2, 7, 9, 10, 17, 18, 25, 26, 27.

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

1. Data file names were standardized to OCM file naming convention (retaining USGS names).

2. The LAStools software scripts lasinfo and lasvalidate were run on the las files to check for errors.

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

4. Internal OCM scripts were run on the las files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12A model, to convert from VA State Plane South coordinates to geographic coordinates, to convert from elevations in survey feet to meters, to assign the geokeys, to sort the data by gps time and zip the data to database and to http.

Process Date/Time: 2018-01-29 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 50784
GUID: gov.noaa.nmfs.inport:50784
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2017-12-15 09:16+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-08-15 17:09+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16