2011 MDEQ Tennessee-Tombigbee Waterway Lidar Survey
This kmz file shows the extent of coverage for the 2006 MDEQ Tennessee-Tombigbee Waterway,
MS lidar data set.
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. The Nominal Point Spacing
Value for the final lidar is 3.2 ft (~1 m). Deliver LiDAR Bare Earth and Contour lines
within the areas designated in areas of Clay, Itawamba, Monroe, and Lowndes Counties
to aid in visual interpretation of Flood Basin elevations and for addition to the
MDEM elevation dataset. 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)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||Reflective surface data represents the DEM created by laser energy reflected from
the first surface encountered by the laser pulse. Some energy may continue beyond
this initial surface to be reflected by a subsequent surface as represented by the
last return data. Intensity information is captured from the reflective surface pulse
and indicates the relative energy returned to the sensor as compared to the energy
transmitted. The intensity image is not calibrated or normalized but indicates differences
in energy absorption due to the interaction of the surface materials with laser energy
at the wavelength transmitted by the sensor. Points are classified as water, bare
ground or not bare ground to support creation of a bare earth model from the data.
||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.
|| Unknown to Unknown
|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
- The Atlantic Group
| Processing Steps
- The ABGPS, IMU, and raw Optech LiDAR data are integrated into the Optech post processor
software. The resultant file is in a LAS binary file format. The LAS file version
1.2 formats 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#, intensity
value, xyz, etc.). The resultant points are produced in the geodetic coordinates referenced
to the NAD83 horizontal datum and NAVD88 2004.65 vertical datum.
- The unedited data are classified to facilitate the application of the appropriate
feature extraction filters. A combination of proprietary filters is applied as appropriate
for the production of bare earth digital terrain models (dtms). 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. The LiDAR mass points were delivered in American Society
for Photogrammetry and Remote Sensing LAS 1.2 format. The header file for each dataset
is complete as define by the LAS 1.2 specification. The data was classified as follows:
Class 1 = Unclassified. This class includes all non-ground classified points. Class
2 = Ground. Class 7 = Low Points. Class 9 = water. Class 9 = water. Class 10 = Ignored.
Class 11 = Overlap Points.
- Conversion from Geodetic coordinates NAD83 into Mississippi state plane zone 16 East
using NAD83 and conversion from ellipsoid heights (us feet) into orthometric heights
using NAVD88 (US Survey Foot). Files are orthogonally tiled based to a 1500m x1500m
extent, and labeled with a "Tile_ID" attribute.
- 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 East 2301,
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 East 2301)
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 535 ft and below 100 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 bathy points, though these points are overlap points, Class
- 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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