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OCM Partners, 2024: 2012 Suwannee River Water Management District (SRWMD) Lidar: Bradford (FL),

Item Identification

Title: 2012 Suwannee River Water Management District (SRWMD) Lidar: Bradford (FL)
Short Name: fl2012_srwmd_bradford_m4893_metadata
Status: Completed
Publication Date: 2015-05

USGS - Suwannee River Water Management District

Contract No.G10PC00093, Task Order No.G12PD00242

Prime Contractor: Digital Aerial Solutions (DAS)

Sub-Contractor: Gustin, Cothern & Tucker, Inc. (GCT)

The Vertical Accuracy Requirements are required to meet or exceed an RMSEz of 9.25 centimeters and a Fundamental Vertical Accuracy requirement of 18.2 centimeters at the 95% Confidence Level according to the NDEP guidelines.

Digital Aerial Solutions, LLC (DAS) was tasked to collect and process a Light Detection And Ranging

(LiDAR) derived elevation dataset for the Suwannee Management, FL. The Suwannee Management survey

area encompasses approximately 725 square miles. Aerial LiDAR data was collected utilizing an ALS60.

The ALS60 is a discrete return topographic LiDAR mapping system manufactured by Leica Geosystems.

LiDAR data collected for the Suwannee Management survey has a nominal pulse spacing of 0.9 meters,

and includes up to 4 discrete returns per pulse, along with intensity values for each return.


LiDAR datasets were post processed to generate elevation point cloud swaths for each flight line.

Deliverables include the point cloud swaths, tiled point clouds classified by land cover type, breaklines to support hydro-flattening of digital elevation models (DEM)s, and bare-earth DEM tiles. Point cloud deliverables are stored in the LAS version 1.2 format, point data record format 1. The tiling scheme for tiled deliverables is a 5000 Feet x 5000 Feet grid aligned and named according Florida State plane North index. All deliverables were generated in conformance with the U.S. Geological Survey National Geospatial Program Guidelines and Base Specifications, Version 13 - ILMF 2010.



Supplemental Information:

A report for this project is available at:

A report for this project is available at:

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


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None Ground
None Terrain

Temporal Keywords

Thesaurus Keyword
None 2012
None Spring

Physical Location

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

Data Set Information

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

LAS 1.2 format (classes 1,2,7,9,10,15,17,18)

Entity Attribute Detail Citation:


Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of Digital Aerial Solutions, SRWMD, USGS, NOAA, the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 673150
Date Effective From: 2015-05
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: 673152
Date Effective From: 2015-05
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: 673153
Date Effective From: 2015-05
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: 673151
Date Effective From: 2015-05
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: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1136884
W° Bound: -82.301917
E° Bound: -82.027309
N° Bound: 30.15012
S° Bound: 29.70548

Extent Group 1 / Time Frame 1

CC ID: 1136883
Time Frame Type: Range
Start: 2012-03-27
End: 2012-03-29

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:

The data set is dynamically generated based on user-specified parameters.;

Data Access Constraints:


Data Use Constraints:

The data depicts the elevations at time of survey and are accurate only for that time. Exercise professional judgment in using this data.

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: 740841
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: 740842
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 740844
URL Type:
Online Resource


CC ID: 740845
URL Type:
Online Resource


CC ID: 740846
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz

This graphic shows the lidar coverage for the 2013 extent of a project in Bradford in Florida.

Activity Log

Activity Log 1

CC ID: 673171
Activity Date/Time: 2017-10-20

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 673170
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: 718252
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 740843
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Data Quality


There is not a systematic method of testing when testing horizontal accuracy in LiDAR. The horizontal accuracy is checked by collecting building corners during the survey. Lines are then digitized representing the building outline and the differences are measure from each individual survey point to the corner of the building outline. Stats are calculated to ensure horizontal tolerances are met. These measurements resulted in an RMSE of .42 meters and equals a .73 meter horizontal accuracy at the 95 % confidence level.

Horizontal Positional Accuracy:

Horizontal accuracy assessments of LiDAR data require the presence of vertical targets such as buildings within in the survey area. Field check points are surveyed at the corners of the building roofs, and the surveyed locations compared to the estimated corner locations in the LiDAR point cloud. The Suwannee Management survey area did not present any accessible buildings for use as vertical targets.

From the manufacturer specifications, the estimated horizontal accuracy at one sigma, based on flying height for the project, is between 10 cm and 20 cm.; Quantitative Value: 0.20 meters, Test that produced the value: +/- 20 cm

Vertical Positional Accuracy:

Local TIN models of the elevation points are built around each ground check points. The tin model elevation is sampled at the horizontal position of the ground check point. The TIN model elevation and ground check point survey elevation values were used to calculate the fundamental vertical accuracy (FVA) of the swath point clouds as described in Section 1.5 of the NDEP Elevation Guidelines Version 1. The FVA of the TIN tested RMSEz 0.19 feet and 0.38 feet at the 95 percent confidence level in open terrain. FVA of the DEM tested at an RMSEz of 0.19 feet and 0.37 feet at the 95% confidence level in open terrain. The full calculations for all check points can be found in Appendix D of the lidar report.; Quantitative Value: 0.058 meters, Test that produced the value: 5.8 cm RMSE (~0.19 ft)


RMSEZ = 0.19 ft


RMSEZ = 0.19 ft

Completeness Measure:

Cloud Cover: 0

Completeness Report:

Ground Truth data was collected of the major land cover classes dispersed within the area of interest. 30 points were collected in each of the classes if the land cover was more then 10% of the AOI.

Conceptual Consistency:

The GPS survey was tied into the Trimble VRS Now Network located in Florida. The Trimble VRS Now network is a network of continuously operating GPS reference stations that provides Real Time Kinematic (RTK) capabilities within a Real Time Network (RTN). This allows corrections to be applied to the points as they are being collected, eliminating the need for an adjustment. Several existing control monuments listed in the NSRS database were used as checks within the Trimble VRS Now Network. This confirmed network accuracies were being met during the field survey as well as providing a redundancy check on the Trimble VRSnetwork. The Specified local network accuracy of 5cm at the 95% confidence level was met or exceeded. Data analysis was accomplished by comparing ground truth checkpoints with LIDAR points from the edited data set, which were within 3.3 feet horizontally from the ground truth points. Based on the number of returns and the density of points in this project, it was not necessary to compare to anything further away than 3.3 feet horizontally from the ground truth points. Note that the edited LIDAR points are simply a subset of the raw LIDAR points. The points that fell above the ground surface on vegetation canopies, buildings, or other obstructions were removed from the data set. Comparisons were also made between the survey points and the LIDAR derived terrain surface. These comparisons provide an additional verification of the LIDAR data against the survey data.


Process Steps

Process Step 1

CC ID: 1136877

The ABGPS, inertial measurement unit (IMU), and raw scans are collected during the LiDAR aerial survey. The ABGPS monitors the xyz position of the sensor and the IMU monitors the orientation. During the aerial survey, laser pulses reflected from features on the ground surface are detected by the receiver optics and collected by the data logger. GPS locations are based on data collected by receivers on the aircraft and base stations on the ground. The ground base stations are placed no more than 40 km radius from the flight survey area.

Process Date/Time: 2013-01-22 00:00:00

Process Step 2

CC ID: 1136878

The ABGPS, IMU, and raw scans are integrated using proprietary software developed by Leica and delivered with the Leica System. The resultant file is in a LAS binary file format. The LAS version 1.2 file format can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return number, intensity value, xyz, etc.). The LiDAR mass points were processed in American Society for Photogrammetry and Remote Sensing LAS 1.2 format. The header file for each dataset is complete as defined by the LAS 1.2 specification. The datasets were divided into a 1500m by 1500m tiling scheme, based on the US National Grid. The tiles are contiguous, do not overlap, and are suitable for seamless topographic data mosaics that include no "no data" areas. The names of the tiles include numeric column and row designations and all files utilize the LAS file extension

Process Date/Time: 2013-01-22 00:00:00

Process Step 3

CC ID: 1136879

The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters are applied as appropriate for the production of bare earth digital elevation models (DEMs). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces.

Process Date/Time: 2013-02-15 00:00:00

Process Step 4

CC ID: 1136880

Filtered and edited data are subjected to rigorous QA/QC. A series of quantitative and visual procedures are employed to validate the accuracy and consistency of the filtered and edited data. Ground control is established by DAS and GPS-derived ground control points (GCPs) in various areas of dominant and prescribed land cover. These points are coded according to land cover, surface material, and ground control suitability. A suitable number of points are selected for calculation of a statistically significant accuracy assessment, as per the requirements of the National Standard for Spatial Data Accuracy. A spatial proximity analysis is used to select edited LiDAR data points within a specified distance of the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative error, and adequate sample size. Accuracy validation and evaluation is accomplished using proprietary software to apply relevant statistical routines for calculation of Root Mean Square Error (RMSE) and the National Standard for Spatial Data Accuracy (NSSDA), according to Federal Geographic Data Committee (FGDC) specifications.

Process Date/Time: 2013-02-28 00:00:00

Process Step 5

CC ID: 1136881

The NOAA Office for Coastal Management (OCM) received the files in las format from SRWMD. The files contained lidar elevation and intensity measurements. The data were in State Plane Zone 903, NAVD88 (orthometric) heights in feet. OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. The data were converted from State Plane coordinates to geographic coordinates.

2. The data were converted from NAVD88 (orthometric) heights in feet to GRS80 (ellipsoid) heights in meters using Geoid 09.

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

4. Duplicate points and erroneous elevations were removed.

5. Class 11 were reclassed to Class 15.

Process Date/Time: 2015-05-05 00:00:00

Catalog Details

Catalog Item ID: 49703
GUID: gov.noaa.nmfs.inport:49703
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:21+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