2012 MDEQ-FEMA Madison-Yazoo Lidar Survey
This kmz file shows the extent of coverage for the 2012 MDEQ/FEMA Yazoo and Madison
Counties, MS lidar data set.
The project entails the acquisition and processing of LiDAR for approximately 1,265
square miles covering areas of Madison and Eastern Yazoo Counties. Collect and deliver
high-density elevation point data derived from multiple-return light detection and
ranging (LiDAR) measurements for use in supporting topographic analysis, including
applications such as flood plain mapping. Hydro enforced breaklines were collected
within the identified Special Flood Hazard Area for Madison County, MS including an
additional 221sq. miles in the heavily developed areas in Madison County, and 112
sq. miles in a buffered area along the Big Black River in Yazoo County, MS. The data
will be delivered as LiDAR Bare Earth within the areas designated in areas of Madison
and Eastern Yazoo Counties to aid in visual interpretation of Flood Basin elevations
and for addition to the MDEM elevation dataset. Also included in the delivery was
LiDAR Intensity data in Tiff format. The intensity values are a measure of the return
signal strength. It measures the peak amplitude of return pulses as they are reflected
back from the target to the detector of the LiDAR system. These intensity images are
a very useful tool to clients and can be used as a substitute for orthophotos. All
data will comply with mapping guidelines and specifications as stated in the FEMA
Procedure Memorandum No.61.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
||Mississippi Department of Environmental Quality
- Mississippi Department of Environmental Quality (MDEQ)
- DHS/FEMA > Federal Emergency Management Agency, U.S. Department of Homeland Security
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||Atlantic Group will provide LiDAR products to support MDEQ in supporting solutions
for a variety of purposes including updating DFIRM maps, hydrologic modeling, transportation
routing, floodplain mapping and assessment of natural hazards. Furthermore, the data
sets can be utilized by the general public including engineers, surveyors, appraisers
and others interested parties to evaluate transportation and land use planning.
||2012-02-19 to 2012-02-24
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Land Surface
- Digital Terrain Model
- Elevation Data
- Ground Control
- Point Cloud
- LAS Point Files
- Bare Earth
- Point Cloud
- Light Detection and Ranging
- Digital Elevation
- Remote Sensing
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
- Atlantic Group, LLC
- The Atlantic Group
- The Atlantic Group
- The Atlantic Group
| Processing Steps
- The flight path will be planned as a series of parallel flight lines with cross flight
lines for the purposes of quality control. In addition, the flight plan will include
flight line distances of 45 kilometers or less and zigzag flight line collection as
a result of the inherent IMU drift associated with IMU systems. A digital flight line
layout using OPTECH ALTM NAV flight design software for direct integration into the
aircraft flight navigation system was created and used.
- LiDAR Sensor Calibration and LiDAR Processing. LIDAR calibrations are performed to
determine and eliminate systematic bias that may occur within the hardware of the
ALTM system. The systematic bias that are corrected involve scale, roll, and pitch.
In addition to the calibration process regarding sensor installation, for every mission,
the runway is kinematically surveyed by making three passes. The LiDAR system is flown
at right angles over the runway several times and residuals are generated from the
- Breaklines were captured within the identified SFHA for Madison County, MS, including
a buffered 112 sq. mile area along the Big Black River in Yazoo County, MS. The breaklines
are significant hydrological features that are appropriate to support the future development
of 2-foot contours meeting a 1.19-foot absolute vertical accuracy at the 95% confidence
level. Horizontal accuracy is computed using the formula RMSE (z) x 1.7308: 1-inch
= 100 feet equivalent (Accuracy = 2.2 feet or 0.67 meters) as defined by the ASPRS
Guidelines: Accuracy Reporting for topographic Data. This guideline implements the
National Standard for Spatial Data Accuracy (NSSDA) for testing of topographic data.
- Digital Elevation Models (DEMs) are generated in spatial software and have a final
cell size of 4 feet. Each DEM is a 32-bit floating point GeoTiff.
- The NOAA Coastal Services Center (CSC) received topographic files in .laz format from
the Mississippi Department of Environmental Quality (MDEQ). The files contained lidar
elevation measurements. The data were received in Mississippi State Plane West 2300,
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 laz files
were converted from a Projected Coordinate System (Mississippi State Plane West 2300)
to a Geographic Coordinate system (NAD 83). 2. The topographic laz files' horizontal
units were converted from feet to decimal degrees. 3. The topographic laz files were
cleaned of error points above 492 ft and below 114 ft. 4. The topographic laz files'
were converted from NAVD88 elevations to NAD83 ellipsoidal elevations using Geoid03
5. Classification 11 was moved to classification 12 due to CSC system requirements
(class 11 is reserved for bathymetric points, though these points are overlap points,
- 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: 2013-10-17
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