2011 U.S. Geological Survey Topographic LiDAR: Suwannee River Expansion
This kmz file shows the extent of coverage for the 2011 USGS Suwannee River lidar
USGS Task Order No. G10PD00236 USGS Contract No. G10PC00093 The Light Detection and
Ranging (LiDAR) dataset is a survey of the Suwannee River Expansion in north-central
Florida. The entire survey area encompasses 950 square miles. The LiDAR point cloud
was flown at a nominal post spacing of 1.0 meters for unobscured areas. The LiDAR
data and derivative products produced are in compliance with the U.S. Geological Survey
National Geospatial Program Guidelines and Base Specifications, Version 13-ILMF 2010.
The flight lines were acquired by Digital Aerial Solutions. This data set is divided
into 4 Areas: A, B, C, and D. Area A: Portions of Dixie, Levy, and Gilchrist Counties
Area B: Portions of Lafayette, Suwannee, and Madison Counties Area C: Suwannee County
Area D: Bradford and Union Counties A map of each Area can be found in the Task Order
Detail listed below. This data set is classified according to ASPRS LAS V1.2 standards.
The classifications for this data set are as follows: Class 1: Unclassified Class
2: Ground Class 7: Noise Class 9: Water Class 10: Ignored Ground (Breakline Proximity)
Class 12: Overlap (Witheld)
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
United States Geological Survey, National Geospatial Technical Operations Center (NGTOC)
- DOI/USGS > United States Geological Survey, U.S. Department of the Interior
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||LiDAR points in LAS 1.2 format (ASPRS Classes 1,2,7,9,10,13)
||This regional LiDAR elevation mapping was obtained under the American Recovery and
Reinvestment Act (ARRA) of 2009.
||2011-03-17 to 2011-04-06
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Remote Sensing
- Hamilton County
- Lafayette County
- Suwannee County
- Columbia County
- Union County
- Bradford County
- Gilchrist County
- Dixie County
- Levy County
- Madison County
- Suwannee River
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| Processing Steps
- 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.
- 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 resultant points
are produced in the NAD83/2007 HARN State Plane Florida North Coordinate System, with
units in U.S. Feet and referenced to the NAVD88 datum. 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 5000 ft by 5000 ft tiling scheme, based on the Florida
state grid network. 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
- 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.
- Filtered and edited data are subjected to rigorous QA/QC, according to the 3001 Operating
Unit Quality Control Plan and procedures. 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 Northrop Grumman, 3001 Operating Unit 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.
- The NOAA Coastal Services Center (CSC) received topographic files in LAS 1.2 format.
The files contained lidar elevation measurements. The data were received in Florida
State Plane North Zone 0903, NAD83 coordinates and were vertically referenced to NAVD88
using the Geoid09 model. The vertical units of the data were feet. CSC performed the
following processing for data storage and Digital Coast provisioning purposes: 1.
The topographic las files were converted from orthometric (NAVD88) heights to ellipsoidal
heights using Geoid09. 2. The topographic las files were converted from a Projected
Coordinate System (FL SP North) to a Geographic Coordinate system (NAD83). 3. The
topographic las files' vertical units were converted from feet to meters. 4. The topographic
las files' horizontal units were converted from feet to decimal degrees. 5. Class
11 (Witheld) was changed to Class 13. 6. The data were converted to LAZ format.
- The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are currently
being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS or LAZ
The LAS format is an industry standard for LiDAR data developed by the American Society
of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version
LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively
in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically
the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most
up to date geoid model when transforming to orthometric heights.
Metadata Last Modified: 2013-06-28
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