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OCM Partners, 2024: 2007 Southwest Florida Water Management District (SWFWMD) LiDAR: Hernando County,

Item Identification

Title: 2007 Southwest Florida Water Management District (SWFWMD) LiDAR: Hernando County
Short Name: swfwmd_hernando_m78_metadata
Status: Completed
Publication Date: 2008-02-18

This dataset is one component of a digital terrain model (DTM) for the Southwest Florida Water Management Districts FY2006 Digital

Orthophoto (B089) and LiDAR Project (L776) encompassing approximately 462 square miles in Hernando County, Florida. This dataset is

comprised of 530 LiDAR files, based on the DISTRICT 5,000' by 5,000' sheet index system in the LAS version 1.1 file format. LiDAR

acquisition dates were January 11 through January 16, 2007. The raw data was collected at an average ground sample distance of

2.1 feet. Other components of the DTM include a personal geodatabase in accordance with the SWFWMD 2006 Topographic Database Design

containing: obscured vegetation polygons; road overpass polygons; road breaklines; soft feature breaklines; water body polygons;

coastal shorelines; hydrographic features breaklines; island polygons; and 1-foot contours. Final products include FEMA-compliant

LIDAR-derived DTM data and 1-foot contours (for cartographic visualization purposes only) meeting or exceeding National Map Accuracy

Standards for 2-foot contours.

Original contact information:

Contact Name: Mapping and GIS

Contact Org: Southwest Florida Water Management District

Phone: (352) 796-7211


The DTM was developed to support the District's regulatory, land management and acquisition, planning, engineering, and habitat

restoration projects.



Supplemental Information:

Project Title: FY2007 Digital Orthophoto (B089) and LiDAR Project (L776) Purchase Order: 07POSOW0322 Work Order Name: North District

One-Foot Orthophoto and LiDAR - Work Order 1 Vendor Name: Woolpert, Inc.

The Hernando County LiDAR Final Report may be viewed at:

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


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None Surface
None Terrain

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
Entity Attribute Overview:

Refer to LAS Specification version 1.1

Entity Attribute Detail Citation:

See process steps within this metadata record for specific methodology

Distribution Liability:

Any conclusions drawn for the analysis of this information are not the responsibility of the Southwest Florida

Water Management District (SWFWMD), the Office for Coastal Management, or its partners.

Data Set Credit: Acknowledgement of the Southwest Florida Water Management District would be appreciated in products derived from these data.

Support Roles

Data Steward

CC ID: 687261
Date Effective From: 2008-02-18
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 687263
Date Effective From: 2008-02-18
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 687264
Date Effective From: 2008-02-18
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 687262
Date Effective From: 2008-02-18
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1140392
W° Bound: -81.925929
E° Bound: -81.848175
N° Bound: 28.35011
S° Bound: 28.308789

Extent Group 1 / Time Frame 1

CC ID: 1140391
Time Frame Type: Range
Start: 2007-01-11
End: 2007-01-16

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:;

Data Access Constraints:


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. DTM accuracy specifications are valid only within the Hernando County limits. The user is cautioned that any DTM data

falling outside of the Hernando County limits may not meet the accuracy specifications.

Metadata Use Constraints:

This dataset is not valid without the signed and sealed copy of the Florida Minimum Technical Standards Report

of Specific Purpose Survey dated 4/31/2008. Please refer to this document for user constraints.

Distribution Information

Distribution 1

CC ID: 742634
Download URL:
File Name: Customized Download

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

Distribution 2

CC ID: 742635
Download URL:
File Name: Bulk Download

Simple download of data files.

Activity Log

Activity Log 1

CC ID: 687281
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 687280
Activity Date/Time: 2017-11-14

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

Activity Log 3

CC ID: 718621
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742636
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Data Quality


Refer to SWFWMD MTS Survey Report, FY2007 Digital Orthophoto and LiDAR (dated 4/31/2008).

Horizontal Positional Accuracy:

Horizontal accuracy shall be tested to meet or exceed a 4.5 foot (1.37 m) horizontal accuracy at 95 percent confidence level

using RMSE(r) x 1.7308 as defined by the National Standard for Spatial Data Accuracy (NSSDA). See SWFWMD MTS Report of DOI Survey,

FY2007 Digital Orthophoto and LiDAR B089 & L776 (dated 4/31/2008)).

Vertical Positional Accuracy:

Tested vertical accuracy of the LiDAR data is 0.45 ft (13.71 cm) at the 95% confidence level for unobscured locations. See

SWFWMD MTS Report of DOI Survey, FY2007 Digital Orthophoto and LiDAR (B089 & L776 (dated 4/31/2008)).

Completeness Measure:

Cloud Cover: 0

Completeness Report:

All elevation measurements within the bounding coordinates of this XML were used to derive this dataset.

Conceptual Consistency:

The LiDAR DTM was developed in accordance with the Federal Emergency Management Agency's (FEMA) Guidelines and Specifications for

Flood Hazard Mapping Partners, Appendix A: Guidance for Aerial Mapping and Surveying, April 2003, and in accordance with the

2007 SWFWMD LiDAR specifications.



Hernando County, Florida: Digital Terrain Model Derived From 2006 Aircraft Laser Elevation Measurements

CC ID: 1140384
Publish Date: 2006-08-24
Extent Type: Discrete
Extent Start Date/Time: 2006-08-24
Source Contribution:

Unknown | Source Geospatial Form: Model | Type of Source Media: Digital tape media

Process Steps

Process Step 1

CC ID: 1140385

The LiDAR data was acquired using a Leica ALS50 from an average altitude of 2,400-feet above ground level to provide an average

ground sample distance of 2.1-feet. First and last return data was collected along with the signal return intensity. Two

redundant airborne GPS bases stations were utilized during the data acquisition with maximum line-of-sight distance between

the base station and aircraft of 20-km. The LiDAR data was reduced using Grafnav (Waypoint Consulting) for GPS post-processing,

PosProc (Applanix Crop) for IMU processing, ALS50 Post Processor (LH Systems) to initial LiDAR processing, TerraScan (Terrasolid)

for initial point classification, and proprietary Woolpert developed software for refining the point classification and QC.

The LiDAR data was reviewed in 3D using a digital photogrammetric work station using ADS40 digital stereo imagery. During the

production process, LiDAR data gaps between the flight lines were observed. These gaps between flight lines were corrected by

adding photogrametrically compiled mass points. These points are classified as class 10, in the LAS file. In the areas with the

compiled mass points, it may be noted that the mass points are not as dense the areas with complete LiDAR coverage. The mass

points were compiled at a sufficient density to define the surface to contract specifications. The LAS files contain 5

classifications: 1 = unclassified; 2 = ground; 9 = water; 10 = photogrammetric masspoints; and 11 = swamp and/or wetlands.

The class 1 consists of all points not on the ground. Class 2 consists of bare earth points. Class 9 consists of points within

water polygons. Class 11 consists of points within swamps and/or wetlands. Class 10 consists of supplementary mass points that

were photogrametrically compiled on point's features such as peaks or pits, and LiDAR data gaps. These points were created to

maintain the accuracy of the DTM. 3D breaklines were collected at the digital photogrammetric workstation during the LiDAR data

review. These breaklines were delineated to insure the DTM is hydrologically correct. Hydrologically Enforced Elevation Data is

defined as "Hydorenforced TINS, DEMS, or contours ensure that top surfaces of bridges and culverts are cut by stream breaklines

so that computer models will accurately represent drainage flow" per FEMA's Appendix A A.4.10. The breaklines were collected

for hydrologically significant features as appropriate to support the development of the generation of 2-foot contours meeting

National Map Accuracy Standards. The following breakline features were classified and separated: Closed Water Body Features,

Linear Hydrographic Features, Coastal Shorelines, Road Features, Soft Features, Obscured Vegetated Areas, Island Features,

Overpasses, and Bridges. Per contract specifications, culverts were not collected as part of this project. Therefore continuity

of hydrographic features may not be consistent. During final data production and analysis, the occurrence of mound type features

in the data set was noted. These areas were checked, and verified to be above ground septic systems. For a complete description

of survey methods, processing methods, software, system parameters, and accuracy analysis, see the Florida MTS Report of

Specific Purpose Survey, SWFWMD MTS Report of DOI Survey, FY2007 Digital Orthophoto and LiDAR (B089 & L776 (dated 4/31/2008))

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

Process Step 2

CC ID: 1140386

Dataset copied.

Process Step 3

CC ID: 1140387

Dataset copied.

Process Step 4

CC ID: 1140388

Dataset copied.

Process Step 5

CC ID: 1140389

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

elevation measurements. The data was in Florida State Plane Projection and NAVD88 vertical datum. OCM performed the following processing

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

1. The data were converted from Florida State Plane West 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: 2008-04-24 00:00:00

Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity Point

Catalog Details

Catalog Item ID: 50019
GUID: gov.noaa.nmfs.inport:50019
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