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Short Citation:
OCM Partners, 2022: 2006 Texas Water Development Board (TWDB) Lidar: Victoria County, https://www.fisheries.noaa.gov/inport/item/50044.

Item Identification

Title: 2006 Texas Water Development Board (TWDB) Lidar: Victoria County
Short Name: tx2006_victoria_m88_metadata
Status: Completed
Publication Date: 2007-08
Abstract:

Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 94 flight lines of standard density (1.4 meter ground

sample distance) data were collected over areas in Victoria County, TX (approximately 891 square miles). Multiple returns

were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 7 missions

between June 14, 2006, June 16, 2006, June 19, 2006 and another collection between June 23, 2006 and June 26, 2006. The data

was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency

Management Agency (FEMA).

Original contact information:

Contact Name: Ryan Mitchell

Contact Org: Texas Natural Resources Information System (TNRIS)

Phone: 512-463-8337

Email: lidar@tnris.state.tx.us

Purpose:

This LIDAR operation was designed to provide a high density set of masspoints within the defined areas. The data

sets are suitable for the development of contours for use in hydraulic/hydrologic model development, and for assessing

environmental impacts. Typical uses for the data set include: FEMA Flood Plain Map Modernization, DFIRM map updates,

watersheds and other hydro studies per FEMA specifications, county mapping projects, and flood mitigation assessment.

Notes:

10688

Supplemental Information:

The Victoria County data set was received from the Texas Water Development Board (TWDB). It was reviewed by the

NOAA Office for Coastal Management at the macro level, which included checking for format and point characteristics for approximately

5% of the tiles. In addition, the entire data set was reviewed to establish that bare earth processing and proper classification

of the points had been performed. It did not include accuracy or data processing (e.g. bare earth quality, flightline

mismatch, feature removal) assessments. Based on the limited review, the data set on average appeared to be of fair quality.

This determination is based on the issues listed under the reviews below. Again, no accuracy assessment was performed.

The results may be viewed as a formatted document. This document is entitled "Lidar Fact Sheet: Victoria County, Texas,"

and may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/88/supplemental/victoria_fact-sheet.pdf

Tile Review

Some minor formatting issues were noted:

1) Ground classified points were in some cases listed as return one of two returns.

2) Some/many flightlines have no first returns (only 2 of 2) but have bare earth.

3) Many files have only first returns.

4) No flightline source information.

Although these are directly related to bare-earth quality, the issues above (1, 2, and 3) raise questions regarding the data

processing.

Bare Earth Point Density Review

Figure 1 of the pdf depicts the bare-earth point density per 2500 sq meter cell and per sq meter. The issues determined in this

review are as follows:

1) There are noticeable point density deficiency "strips" in the middle of the county. This may be a sensor issue.

2) The northern portion of the county appears to have collected well.

3) The southern portion has some specific "flightline" point density (classification) variance.

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

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/88/supplemental/2006_TWDB_Lidar_Victoria_County.kmz

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Drainage Area
None Hydraulic
None Hydrographic
None Hydrology
None TNRIS (Texas Natural Resources Information System)

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Distribution Liability:

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

Data Set Credit: Data collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA). Acknowledgement of TNRIS (Texas Natural Resources Information System) would be appreciated in products derived and used from this data. Sanborn Mapping Company asks to be credited in derived products.

Support Roles

Data Steward

CC ID: 688276
Date Effective From: 2007-08
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: 688278
Date Effective From: 2007-08
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: 688279
Date Effective From: 2007-08
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: 688277
Date Effective From: 2007-08
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: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1142580
W° Bound: -97.305792
E° Bound: -96.655992
N° Bound: 29.103773
S° Bound: 28.485973

Extent Group 1 / Time Frame 1

CC ID: 1142575
Time Frame Type: Discrete
Start: 2006-06-14

Extent Group 1 / Time Frame 2

CC ID: 1142576
Time Frame Type: Discrete
Start: 2006-06-16

Extent Group 1 / Time Frame 3

CC ID: 1142577
Time Frame Type: Discrete
Start: 2006-06-19

Extent Group 1 / Time Frame 4

CC ID: 1142578
Time Frame Type: Discrete
Start: 2006-06-23

Extent Group 1 / Time Frame 5

CC ID: 1142579
Time Frame Type: Discrete
Start: 2006-06-26

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;

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: 742758
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=88
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: 742759
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/88/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 742761
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 742762
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 688305
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 688304
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: 718650
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742760
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Technical Environment

Description:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350

Data Quality

Horizontal Positional Accuracy:

FEMA LiDAR Specifications

Vertical Positional Accuracy:

FEMA LiDAR Specifications; +/- 18 cm in open terrain

Completeness Report:

None

Conceptual Consistency:

None

Lineage

Process Steps

Process Step 1

CC ID: 1142567
Description:

Data Collection:

Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 94 flight lines of standard density (1.4 meter ground

sample distance) data were collected over areas in Victoria County, TX (approximately 891 square miles). Multiple returns

were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 7 missions

between June 14, 2006, June 16, 2006, June 19, 2006 and another collection between June 23, 2006 and June 26, 2006. During

the LIDAR campaign, the Sanborn field crew conducted a GPS field survey to establish final coordinates of the ground base

stations for final processing of the base-remote GPS solutions.

Process Date/Time: 2007-08-01 00:00:00

Process Step 2

CC ID: 1142568
Description:

Airborne GPS Processing:

Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best

estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface

for each flight line. The overlap between flight lines was removed to provide a homogeneous coverage, and the coverage was

classified to extract a bare earth digital elevation model (DEM).

Airborne GPS is differentially processed using the GrafNAV V7.50 software by Waypoint Consulting of Calgary, Alberta, Canada.

The PDOP and distance separation is as follows:

IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada.

The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta,

Georgia.

The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of

Helsinki, Finland.

Process Date/Time: 2007-08-01 00:00:00

Process Step 3

CC ID: 1142569
Description:

IMU data Processing:

IMU data provides information concerning roll, pitch, and yaw of collection platform during collection event. IMU information

allows the pulse vector to be properly placed in 3D space allowing the distance from the aircraft reference point to be properly

positioned on the elevation model surface. IMU data is processed using the PosPac V4.2 software by Applanix Corporation of

Richmond Hill, Ontario, Canada.

Process Date/Time: 2007-08-01 00:00:00

Process Step 4

CC ID: 1142570
Description:

Reflective Surface Generation:

The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta,

Georgia.

Process Date/Time: 2007-08-01 00:00:00

Process Step 5

CC ID: 1142571
Description:

LIDAR Point Classification

The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of

Helsinki, Finland.

Process Date/Time: 2007-08-01 00:00:00

Process Step 6

CC ID: 1142572
Description:

Output LAS Files

The product output of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland. LAS Binary,

ascii xyz, and intensity images were created.

Process Date/Time: 2007-08-01 00:00:00

Process Step 7

CC ID: 1142573
Description:

The NOAA Office for Coastal Management (OCM) received the files in las format. The files contained Lidar

elevation and intensity measurements. The data was in UTM projection, and NAVD88 Geoid 03 vertical datum. OCM performed

the following processing to the data to make it available within the Digital Coast:

1. The data were converted from UTM coordinates to geographic coordinates.

2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03.

3. The LAS data were sorted by latitude and the headers were updated.

Process Date/Time: 2008-08-13 00:00:00

Catalog Details

Catalog Item ID: 50044
GUID: gov.noaa.nmfs.inport:50044
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:23+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