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Short Citation:
OCM Partners, 2022: 2010 ARRA Lidar: Eleven County Virginia, https://www.fisheries.noaa.gov/inport/item/50123.

Item Identification

Title: 2010 ARRA Lidar: Eleven County Virginia
Short Name: va2010_arra_11_county_virginia_m2621_metadata
Status: Completed
Publication Date: 2014-03-04
Abstract:

Terrapoint and LMSI collected LiDAR for over 2,572 square miles in Northumberland, Lancaster, Middlesex, King and Queen, Matthews, Gloucester, James City, Williamsburg, Surry, Isle of Wight, and Suffolk Counties in Virginia. The nominal pulse spacing for this project was no greater than 0.7 meters. This project was collected with a sensor which collects waveform data and provides an intensity value for each discrete pulse extracted from the waveform. GPS Week Time, Intensity, Flightline and echo number attributes were provided for each LiDAR point. Dewberry used proprietary procedures to classify the LAS according to USGS ARRA specifications: 1-Unclassified, 2-Ground, 7-Noise, 9-Water, 10-Ignored Ground due to breakline proximity. Dewberry produced 3D breaklines and combined these with the final LiDAR data to produce seamless hydro flattened DEMs and first return DSMs for the 3,199 tiles (5000 ft x 5000 ft) that cover the project area.

Original contact information:

Contact Org: USGS

Title: USGS NGTOC

Phone: (573) 308-3587

Email: pemmett@usgs.gov

Purpose:

The purpose of this LiDAR data was to produce high accuracy 3D elevation products, including tiled LiDAR in LAS 1.2 format, 3D breaklines, and 5 ft cell size hydro flattened Digital Elevation Models (DEMs) and 5 ft cell size Digital Surface Models (DSMs).

Notes:

10767

Supplemental Information:

A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2621/supplemental/va2010_arra_11_county_virginia_m2621.KMZ

Reports explaining collection and quality assurance is available at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2621/supplemental/va2010_arra_11_county_virginia_m2621.pdf

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Data Presentation Form: las
Entity Attribute Overview:

LiDAR points in LAZ format (Classes 1,2,7,9,10)

Entity Attribute Detail Citation:

none

Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility

of Watershed Sciences, PSLC, NOAA, the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 691342
Date Effective From: 2014-03-04
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: 691344
Date Effective From: 2014-03-04
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: 691345
Date Effective From: 2014-03-04
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: 691343
Date Effective From: 2014-03-04
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: 1135155
W° Bound: -77.216413
E° Bound: -76.218342
N° Bound: 38.054124
S° Bound: 36.529391

Extent Group 1 / Time Frame 1

CC ID: 1135154
Time Frame Type: Range
Start: 2010-04-08
End: 2010-05-10

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

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=2621;

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. These data depict the heights at the time of the survey and are only accurate for that time.

Distribution Information

Distribution 1

CC ID: 743150
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2621
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 743151
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2621/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 743153
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 743154
URL: https://coast.noaa.gov
URL Type:
Online Resource

URL 3

CC ID: 743155
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2621/supplemental/va2010_arra_11_county_virginia_m2621.KMZ
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar coverage of the eleven counties of Virginia collected in 2010 to support the ARRA of 2009.

Activity Log

Activity Log 1

CC ID: 691371
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 691370
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718728
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 743152
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Horizontal Positional Accuracy:

Lidar source compiled to meet 3.5 foot horizontal accuracy.; Quantitative Value: 1.06 meters, Test that produced the value: Dewberry does not perform independent horizontal accuracy testing on the LiDAR. LiDAR vendors perform calibrations on the LiDAR sensor and compare data to adjoining flight lines to ensure LiDAR meets the 3.5 ft horizontal accuracy standard at the 95% confidence level. Please see the final project report delivered to the USGS for more details. 3.5 ft = 1.06 m

Vertical Positional Accuracy:

The vertical accuracy of the LiDAR was tested by Dewberry with 105 independent survey checkpoints. The survey checkpoints were evenly distributed throughout the project area and were located in areas of either urban or open terrain.

All checkpoints were used to compute the Fundamental Vertical Accuracy (FVA). Project specifications required a FVA of 1.20 ft (36.2 cm) based on a RMSEz (0.60 ft/18.5 cm) x 1.9600. All checkpoints were used to compute the Consolidated Vertical Accuracy (CVA). Project specifications required a CVA of 1.20 ft (36.2 cm) based on the 95th percentile.; Quantitative Value: 0.22 meters, Test that produced the value: Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA methodology, vertical accuracy at the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for the USGS Eleven County Virginia LiDAR project satisfies the criteria:

Lidar dataset tested 0.75 ft vertical accuracy at 95% confidence level in open and urban terrain, based on RMSEz (0.38 ft) x 1.9600.

Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, consolidated vertical accuracy at the 95% confidence level is computed using the 95th percentile method. The dataset for the USGS Eleven County Virginia LiDAR project satisfies the criteria:

Lidar dataset tested 0.73 ft vertical accuracy at 95% confidence level in all land cover categories combined (urban and open terrain). 0.73 ft = 0.22 m

Completeness Report:

A visual qualitative assessment was performed to ensure data completeness and bare earth data cleanliness. No void or missing data, the bare earth surface is of good quality and data passes vertical accuracy specifications.

Conceptual Consistency:

Data covers the tile scheme provided for the project area.

Lineage

Process Steps

Process Step 1

CC ID: 1135150
Description:

Data for the Eleven County Virginia LiDAR project was acquired by both Terrapoint and LMSI.

Three Optech ALTM 3100EA LiDAR systems were utilized to collect the data. The three aircraft used for the survey were Piper Navaho, registrations C-FVTL (Terrapoint) and C-FVYW (Terrapoint) with an endurance of approximately 6 hours and a Piper Turbo Aztec registration N40204 (LMSI) with an endurance of approximately 7 hours.

Fifty-four (54) flight missions resulting in 477 production lines were required to obtain data over the entire project area. A combination of Sokkia GSR 2600 and NovAtel DL-4+ dual-frequency GPS receivers were used to support the airborne operations of this survey and to establish the GPS control network. Five existing published survey monuments and two newly surveyed points were used as base stations for all missions. Forty-eight (48) additional points were established by LMSI and used for quality control and calibration of the data.

Airborne GPS kinematic data was processed on-site using GrafNav kinematic On-The-Fly (OTF) software. Flights were flown with a minimum of 6 satellites in view (13o above the horizon) and with a PDOP of better than 3. Distances from base station to aircraft were kept to a maximum of 24km.

The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile any data if not complete. Subsequently the mission points are output using Optech's Dashmap, initially with default values from Optech or the last mission calibrated for system. The initial point generation for each mission calibration is verified within Microstation/Terrascan for calibration errors. If a calibration error greater than specification is observed within the mission, the roll pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are regenerated and validated internally once again to ensure quality. All missions are validated against the adjoining missions for relative vertical biases and collected GPS kinematic validation points for absolute vertical accuracy purposes. On a project level, a supplementary coverage check is carried out, to ensure no data voids unreported by Field Operations are present.

Process Date/Time: 2010-05-01 00:00:00

Process Step 2

CC ID: 1135151
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. GeoCue allows the data to retain its delivered tiling scheme (5000 ft by 5000 ft). The tiled data is then opened in Terrascan where Dewberry 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. Once the ground routine has been completed a manual quality control routine is done using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review and 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 corrections were completed, the dataset was 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 which are in close proximity (3 ft) to the hydrographic features are moved to class 10, an ignored ground. In addition to classes 1, 2, 9, and 10, there is a Class 7, noise points. This class was only used if needed when points could manually be identified as low/high points.

The fully classified dataset is then processed through Dewberry's comprehensive quality control program.

The data was classified as follows:

Class 1 = Unclassified. This class includes vegetation, buildings, noise etc.; Class 2 = Ground; Class 7= Noise; Class 9 = Water; Class 10= Ignored Ground

The LAS header information was verified to contain the following:

Class (Integer); GPS Week Time (0.0001 seconds); Easting (0.01 foot); Northing (0.01 foot); Elevation (0.01 foot); Echo Number (Integer 1 to 4); Echo (Integer 1 to 4); Intensity (8 bit integer); Flight Line (Integer); Scan Angle (Integer degree)

Process Date/Time: 2010-10-01 00:00:00

Process Step 3

CC ID: 1135152
Description:

The NOAA Office for Coastal Management (OCM) downloaded topographic files in LAZ format from the website for William and

Mary's Center for Geospatial Analysis. The files contained lidar easting, northing, elevation, intensity,

return number, class, scan angle and GPS time measurements; the data was received in state plane

Virginia South (in feet) and vertical coordinates were referenced to NAVD88 in feet using the Geoid03 model.

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

1. The All-Return LAZ files were checked for erroneous outliers removed, as well as variable length records.

2. The laz files were converted from a Projected Coordinate System (SP 4502) to a Geographic Coordinate system (NAD83)

3. The laz files were then converted to ellipsoidal vertical units in meters using the geoid03 conversion.

Process Date/Time: 2014-03-04 00:00:00

Catalog Details

Catalog Item ID: 50123
GUID: gov.noaa.nmfs.inport:50123
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:24+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+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