<?xml version='1.0' encoding='UTF-8'?>
<metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <idinfo>
    <citation>
      <citeinfo>
        <origin>Jayme Strange</origin>
        <pubdate>20260128</pubdate>
        <title>Mississippi River, Pool 26 Digital Elevation Model, First Return</title>
        <geoform>Raster Digital Data Set</geoform>
        <pubinfo>
          <pubplace>Online</pubplace>
          <publish>U.S. Geological Survey</publish>
        </pubinfo>
        <onlink>https://doi.org/10.5066/P9BLTSTZ</onlink>
      </citeinfo>
    </citation>
    <descript>
      <abstract>In 2007, the U.S Army Corps of Engineers’ Upper Mississippi River Restoration (UMRR) program partnered with the Iowa Department of Natural Resources (IDNR) to collect FEMA-grade, bluff-to-bluff lidar for Navigation Pools 8-24 of the UMRS. In 2009, with American Recovery and Reinvestment (ARRA) funds awarded to UMRR, the remaining lidar for the Upper Mississippi River, to the confluence with the Ohio River, and the Illinois River was contracted. Data acquisition was completed in 2011. Lidar data are remotely sensed, high-resolution elevation data collected by airplane. The Upper Midwest Environmental Sciences Center is processing these data to create Digital Elevation Models (DEMs), 0.5 meter contour lines, and pool-wide hillshade images.</abstract>
      <purpose>Light Detection and Ranging (lidar) generates extremely accurate (vertical and horizontal) location information and has long been a desired product for the UMRS. Lidar data is used for 3D visualization, elevation based analysis and for feature extraction.</purpose>
      <supplinf>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.  Points are classified as on ground surface or not on ground surface to support creation of a bare earth model from the data.</supplinf>
    </descript>
    <timeperd>
      <timeinfo>
        <rngdates>
          <begdate>20091216</begdate>
          <enddate>20111228</enddate>
        </rngdates>
      </timeinfo>
      <current>ground condition</current>
    </timeperd>
    <status>
      <progress>Complete</progress>
      <update>None planned</update>
    </status>
    <spdom>
      <bounding>
        <westbc>-90.771015199004</westbc>
        <eastbc>-90.123150841</eastbc>
        <northbc>39.018497335</northbc>
        <southbc>38.779297845</southbc>
      </bounding>
    </spdom>
    <keywords>
      <theme>
        <themekt>USGS Thesaurus</themekt>
        <themekey>elevation</themekey>
        <themekey>lidar</themekey>
        <themekey>topography</themekey>
        <themekey>digital elevation models</themekey>
        <themekey>digital elevation models</themekey>
      </theme>
      <theme>
        <themekt>None</themekt>
        <themekey>elevation</themekey>
        <themekey>lidar</themekey>
        <themekey>laser</themekey>
        <themekey>topography</themekey>
        <themekey>digital elevation model</themekey>
        <themekey>DEM</themekey>
        <themekey>Surface Model</themekey>
      </theme>
      <theme>
        <themekt>USGS Metadata Identifier</themekt>
        <themekey>USGS:69728d65d4be024aa5bddf76</themekey>
      </theme>
      <place>
        <placekt>U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions (Federal Information Processing Standard (FIPS) 10-4): Washington, D.C., National Institute of Standards and Technology</placekt>
        <placekey>US</placekey>
        <placekey>Mississippi River</placekey>
      </place>
      <place>
        <placekt>State location</placekt>
        <placekey>Missouri</placekey>
        <placekey>Illinois</placekey>
      </place>
      <place>
        <placekt>Mississippi River</placekt>
        <placekey>Upper Mississippi River</placekey>
      </place>
    </keywords>
    <accconst>None.</accconst>
    <useconst>None.</useconst>
    <ptcontac>
      <cntinfo>
        <cntperp>
          <cntper>Jayme Strange</cntper>
          <cntorg>U.S. Geological Survey</cntorg>
        </cntperp>
        <cntpos>Geographer</cntpos>
        <cntaddr>
          <addrtype>mailing and physical</addrtype>
          <address>2630 Fanta Reed Road</address>
          <city>La Crosse</city>
          <state>WI</state>
          <postal>54603</postal>
          <country>US</country>
        </cntaddr>
        <cntvoice>608-781-6290</cntvoice>
        <cntemail>jstrange@usgs.gov</cntemail>
      </cntinfo>
    </ptcontac>
    <datacred>Sanborn Map Company, Inc., Western Air Maps, Inc, US Army Corps of Engineers</datacred>
    <native>Environment as of Metadata Creation: Microsoft [Unknown] Version 6.2 (Build 9200) ; Esri ArcGIS 10.6 (Build 8321) Service Pack N/A (Build N/A)</native>
  </idinfo>
  <dataqual>
    <attracc>
      <attraccr>No formal attribute accuracy tests were conducted.</attraccr>
    </attracc>
    <logic>All DEMS were created from LAS data.  All LAS formatted lidar data are validated using commercial GIS software to ensure proper formatting and loading before delivery.  This validation procedure ensures that data on delivery media is in correct physical format and is readable.The extent of the digital elevation models do not match the lidar SAB (study area boundary) because the las tiles were clipped by the USACE before distributing the tiles to UMESC.</logic>
    <complete>Lidar raster data is visually inspected for completeness to ensure that any gaps between flight lines or loss of signal represents less than 5% of required collection area.  Areas of open water where loss of lidar signal is common are corrected to the best estimate of water level at time of collection.  Lidar is self-illuminating and has minimal cloud penetration capability.  Water vapor in steam plumes or particulates in smoke may cause reflection of lidar signals and loss of elevation information beneath these plumes.  Glass structures and roofs may appear transparent to the lidar signal and therefore may not register on the reflective surface.  Some asphalt formulations have been shown to absorb topographic lidar wavelength energy resulting in "pitting" of roof surfaces using this material.</complete>
    <posacc>
      <horizpa>
        <horizpar>Contracted to meet 1 meter (RMSE) horizontal accuracy.</horizpar>
      </horizpa>
      <vertacc>
        <vertaccr>Contracted to meet 18.5cm (RMSE) on open bare terrain and 37cm (RMSE) in vegetative areas. Western Air Maps used testing procedures consistent with those specified in the National Standard for Spatial Data Accuracy (NSSDA) resulting in a tested vertical accuracy (preliminary checkpoint results located in various vegetation classifications yielded 15 cm (RMS) at 95% confidence level.</vertaccr>
      </vertacc>
    </posacc>
    <lineage>
      <srcinfo>
        <srccite>
          <citeinfo>
            <origin>Sanborn Map Company, Inc., Western Air Maps, Inc</origin>
            <pubdate>2011</pubdate>
            <title>Middle Mississippi River Lidar</title>
            <geoform>Digital and/or Hardcopy Resources</geoform>
            <pubinfo>
              <pubplace>Rock Island, IL</pubplace>
              <publish>USACOE</publish>
            </pubinfo>
            <onlink>na</onlink>
          </citeinfo>
        </srccite>
        <typesrc>Digital and/or Hardcopy Resources</typesrc>
        <srctime>
          <timeinfo>
            <rngdates>
              <begdate>20091216</begdate>
              <enddate>20111228</enddate>
            </rngdates>
          </timeinfo>
          <srccurr>ground condition</srccurr>
        </srctime>
        <srccitea>Source Input 1</srccitea>
        <srccontr>Source information used in support of the development of the data set.</srccontr>
      </srcinfo>
      <srcinfo>
        <srccite>
          <citeinfo>
            <origin>Merrick &amp; Co</origin>
            <pubdate>2008</pubdate>
            <title>Missouri County Las</title>
            <geoform>Las</geoform>
            <pubinfo>
              <pubplace>Jefferson City, Missouri</pubplace>
              <publish>Merrick &amp; Co</publish>
            </pubinfo>
            <onlink>na</onlink>
          </citeinfo>
        </srccite>
        <typesrc>Digital and/or Hardcopy Resources</typesrc>
        <srctime>
          <timeinfo>
            <rngdates>
              <begdate>20081113</begdate>
              <enddate>20081118</enddate>
            </rngdates>
          </timeinfo>
          <srccurr>ground condition</srccurr>
        </srctime>
        <srccitea>Source Input 2</srccitea>
        <srccontr>Missouri County Lidar Data</srccontr>
      </srcinfo>
      <procstep>
        <procdesc>Data Collection: 
Using a Leica ALS 50 Light Detection and Ranging (lidar) system, flight lines of standard density (FEMA grade 1.4-meter ground sample distance) data were collected as part of the project 2000 square mile corridor expanding the Mississippi River from Illinois to Missouri.  Multiple returns were recorded for each laser pulse along with an intensity value for each return.  During the lidar campaign, the field crew conducted a GPS field survey to establish final coordinates of the ground base stations for final processing of the base-remote GPS solutions.  Airborne global positioning system (GPS) base stations were used to support the lidar data acquisition.</procdesc>
        <procdate>200801</procdate>
      </procstep>
      <procstep>
        <procdesc>Airborne GPS Processing: Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the lidar slant range measurements to a raw reflective surface for each flight line. The overlap between flight lines was removed to provide a homogeneous coverage, and the coverage was classified to extract a bare earth digital elevation model (DEM). Airborne GPS is differentially processed using the GrafNAV V7.50 software by Waypoint Consulting of Calgary, Alberta, Canada. The PDOP and distance separation is as follows: IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS &amp; Mapping Division of Atlanta, Georgia. The classification and quality control (QC) of lidar data is carried out using TerraScan software by Terrasolid Limited of Helinski, Finland.</procdesc>
        <procdate>2008</procdate>
      </procstep>
      <procstep>
        <procdesc>IMU data Processing: IMU data provides information concerning roll, pitch and yaw of airplane during collection event. IMU information allows the pulse vector to be properly placed in 3D space allowing the distance from the aircraft reference point to be properly positioned on the elevation model surface. IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada.</procdesc>
        <procdate>2008</procdate>
      </procstep>
      <procstep>
        <procdesc>Reflective Surface Generation: The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS &amp; Mapping Division of Atlanta, Georgia.</procdesc>
        <procdate>2008</procdate>
      </procstep>
      <procstep>
        <procdesc>Lidar Point Classification The classification and quality control of lidar data is carried out using TerraScan software by Terrasolid Limited of Helinski, Finland.</procdesc>
        <procdate>2008</procdate>
      </procstep>
      <procstep>
        <procdesc>Output LAS Files Random lidar points maintained in UTM coordinate system converted to Geographic projection with units of Meters. Assigned point class, "unclassified" = 1; "ground" = 2.</procdesc>
        <procdate>2008</procdate>
      </procstep>
      <procstep>
        <procdesc>Water surfaces were hydroflattened using breaklines.</procdesc>
        <procdate>201505</procdate>
      </procstep>
      <procstep>
        <procdesc>LAS files were converted to first return DEM by using LP360 lidar point cloud processing software. DEM was clipped down to study area boundary.</procdesc>
        <procdate>20200113</procdate>
      </procstep>
    </lineage>
    <cloud>Unknown</cloud>
  </dataqual>
  <spdoinfo>
    <direct>Raster</direct>
    <rastinfo>
      <rasttype>Grid Cell</rasttype>
      <rowcount>25016</rowcount>
      <colcount>55535</colcount>
      <vrtcount>1</vrtcount>
    </rastinfo>
  </spdoinfo>
  <spref>
    <horizsys>
      <planar>
        <gridsys>
          <gridsysn>Universal Transverse Mercator</gridsysn>
          <utm>
            <utmzone>15</utmzone>
            <transmer>
              <sfctrmer>0.9996</sfctrmer>
              <longcm>-93.0</longcm>
              <latprjo>0.0</latprjo>
              <feast>500000.0</feast>
              <fnorth>0.0</fnorth>
            </transmer>
          </utm>
        </gridsys>
        <planci>
          <plance>row and column</plance>
          <coordrep>
            <absres>1.0</absres>
            <ordres>1.0</ordres>
          </coordrep>
          <plandu>METERS</plandu>
        </planci>
      </planar>
      <geodetic>
        <horizdn>D_North_American_1983</horizdn>
        <ellips>GRS_1980</ellips>
        <semiaxis>6378137.0</semiaxis>
        <denflat>298.257222101</denflat>
      </geodetic>
    </horizsys>
  </spref>
  <eainfo>
    <detailed>
      <enttyp>
        <enttypl>Attribute Table</enttypl>
        <enttypd>Table containing attribute information associated with the data set.</enttypd>
        <enttypds>Producer defined</enttypds>
      </enttyp>
      <attr>
        <attrlabl>Value</attrlabl>
        <attrdef>Raster Value</attrdef>
        <attrdefs>Producer defined</attrdefs>
        <attrdomv>
          <rdom>
            <rdommin>81.772850036621</rdommin>
            <rdommax>1978.6984863281</rdommax>
            <attrunit>Meter</attrunit>
          </rdom>
        </attrdomv>
      </attr>
    </detailed>
    <overview>
      <eaover>The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set.</eaover>
      <eadetcit>The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information.</eadetcit>
    </overview>
  </eainfo>
  <distinfo>
    <distrib>
      <cntinfo>
        <cntorgp>
          <cntorg>U.S. Geological Survey - ScienceBase</cntorg>
        </cntorgp>
        <cntaddr>
          <addrtype>mailing and physical</addrtype>
          <address>Denver Federal Center, Building 810, Mail Stop 302</address>
          <city>Denver</city>
          <state>CO</state>
          <postal>80225</postal>
          <country>USA</country>
        </cntaddr>
        <cntvoice>1-888-275-8747</cntvoice>
        <cntemail>sciencebase@usgs.gov</cntemail>
      </cntinfo>
    </distrib>
    <distliab>Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.</distliab>
  </distinfo>
  <metainfo>
    <metd>20260128</metd>
    <metc>
      <cntinfo>
        <cntperp>
          <cntper>Jayme M Strange</cntper>
          <cntorg>U.S. Geological Survey, MIDCONTINENT REGION</cntorg>
        </cntperp>
        <cntpos>Geographer</cntpos>
        <cntaddr>
          <addrtype>mailing and physical</addrtype>
          <address>2630 Fanta Reed Road</address>
          <city>La Crosse</city>
          <state>WI</state>
          <postal>54603</postal>
          <country>US</country>
        </cntaddr>
        <cntvoice>608-781-6290</cntvoice>
        <cnttdd>N/A</cnttdd>
        <cntemail>jstrange@usgs.gov</cntemail>
      </cntinfo>
    </metc>
    <metstdn>Content Standard for Digital Geospatial Metadata</metstdn>
    <metstdv>FGDC-STD-001-1998</metstdv>
    <mettc>local time</mettc>
    <metextns>
      <onlink>http://www.Esri.com/metadata/Esriprof80.html</onlink>
      <metprof>ESRI Metadata Profile</metprof>
    </metextns>
  </metainfo>
</metadata>
