This is collection level metadata for LAS and ASCII data files from the statewide Iowa Lidar Project. The Iowa Light Detection and Ranging (LiDAR) Project collects location and elevation (X, Y, Z) data to a set standard for the entire state of Iowa. LIDAR is defined as an airborne laser system, flown aboard rotary or fixed-wing aircraft, that is used to acquire x, y, and z coordinates of terrain and terrain features that are both manmade and naturally occurring. LIDAR systems consist of a light-emitting scanning laser, an airborne Global Positioning System (GPS) with attendant GPS base station(s), and an Inertial Measuring Unit (IMU). The laser scanning system measures ranges from the scanning laser to terrain surfaces by measuring the time it takes for the emitted light (LIDAR return) to reach the earth's surface and reflect back to the onboard LIDAR detector. The airborne GPS system ascertains the in-flight three-dimensional position of the sensor, and the IMU delivers precise information about the attitude of the sensor. The LIDAR system incorporates data from these three subsystems to produce a large cloud of points on the land surface whose X, Y, and Z coordinates are known within the specified accuracy. This collection consists of ASCII files of bare earth elevations and intensity (x,y,z,i) and, LAS (version 1.0 lidar data interchange standard) binary files that include all 1st and last returns, intensity and bare earth classification.

Color hillshade maps from 2007-2010 high resolution LiDAR terrain mapping project. The Iowa DNR, USDA Natural Resources Conservation Service and other partners funded a multi-year project to collect high-resolution LiDAR terrain data for the State of Iowa. These hillshade maps are a derivative product from 1-meter resolution digital elevation models (DEM) from the LiDAR bare-earth datasets

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between October 25th and 31st, 2020 at several sites in eastern Iowa using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topographic light detection and ranging (lidar) data that was collected between December 7th, 2019 and November 19th, 2020 using wide area mapping lidar systems for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of wide area topographic lidar mapping capabilities that are becoming more widely used in 3DEP. The airborne lidar was collected to support the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Hig ...

This dataset contains lidar water vapor measurements in the boundary layer and analyses in multiple formats as part of CASES-99. The data are located on a CD and have multiple formats.

(In progress)A popular acronym used as a generic term for digital topographic and bathymetric data in all its various forms. Unless specifically referenced as a digital surface model (DSM), the generic DEM normally implies x, y coordinates and z-values of the bare-earth terrain void of vegetation and man-made features.As used by the U.S. Geological Survey (USGS), a DEM is the digital cartographic representation of the elevation of the land at regularly spaced intervals in x and y directions, using z-values referenced to a common vertical datum.As typically used in the United States and elsewhere, a DEM has bare-earth z-values at regularly spaced intervals in x and y directions; however, grid spacing, datum, coordinate systems, data formats, and other characteristics may vary widely.A “D-E-M” is a specific raster data format once widely used by the USGS. DEMs are a sampled array of elevations for a number of ground positions at regularly spaced intervals.

DRAFT LiDAR-derived digital surface model of Iowa from 2020 LiDAR collection.Similar to DEMs except that they may depict the elevations of the top surfaces of buildings, trees, towers, and other features elevated above the bare-earth. DSMs are especially relevant for telecommunications management, air safety, forest management, and 3D modeling and simulation.

(In progress)For discrete-return lidar instruments, intensity is the recorded amplitude of the reflected lidar pulse at the moment the reflection is captured as a return by the lidar instrument. Lidar intensity values can be affected by many factors such as the instantaneous setting of the instrument’s Automatic Gain Control and angle of incidence and thus cannot be equated to a true measure of energy for discrete return systems. In full-waveform systems, the entire reflection is sampled and recorded, and true energy measurements can be made for each return or overall reflection. Intensity values for discrete returns derived from a full-waveform system may or may not be calibrated to represent true energy. Lidar intensity data make it possible to map variable textures in the form of a grayscale image. Intensity return data enable automatic identification and extraction of objects such as buildings and impervious surfaces and can aid in lidar point classification. In spite of their similar appearance, lidar intensity images differ from traditional panchromatic images in several important ways:Lidar intensity is a measure of the reflection of an active laser energy source, not natural solar energy.Lidar intensity images are aggregations of values at point samples. The value of a pixel does not represent the composite value for the area of that pixel.Lidar intensity images depict the surface reflectivity within an extremely narrow band of the electromagnetic spectrum, not the entire visible spectrum as in panchromatic images.Lidar intensity images are strongly affected by the angle of incidence of the laser to the target and are subject to unnatural shadowing artifacts.The values on which lidar intensity images are based may or may not be calibrated to any standard reference. Intensity images usually contain wide variation of values within swaths, between swaths, and between lifts.For these reasons, lidar intensity images must be interpreted and analyzed with unusually high care and skill.

Product: These lidar data are processed Classified LAS 1.4 files, formatted to individual 4500 ft x 4500 ft tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

Geographic Extent: 4 counties in Wisconsin WI_12County_3 (Work Unit 300206) covering approximately 590 square miles in Green County WI_12County_4 (Work Unit 300207) covering approximately 77...

Used by Districts to show the difference between the LiDAR collected clearance and what we had on record.

NCALM. PI: Witold Krajewski, University of Iowa. The two survey areas are both irregular polygons. The first polygon enclosed approximately 282 square kilometers and was centered on the Iowa River from the Coralville Dam just north of Iowa City, Iowa and continuing south. The second polygon enclosed 282 km square and was centered on the Clear Creek Watershed. The data were collected to survey the Iowa River Flood along the Iowa River and Clear Creek Watershed. The data collection was funded by NSF Small Grant for Exploratory Research (SGER) program. Publications associated with this dataset can be found at NCALM's Data Tracking Center

DRAFT LiDAR-derived digital surface model hillshade from 2020 Iowa LiDAR collection.Similar to DEMs except that they may depict the elevations of the top surfaces of buildings, trees, towers, and other features elevated above the bare-earth. DSMs are especially relevant for telecommunications management, air safety, forest management, and 3D modeling and simulation.

Hillshade maps from 2007-2010 high resolution LiDAR terrain mapping project. The Iowa DNR, USDA Natural Resources Conservation Service and other partners funded a multi-year project to collect high-resolution LiDAR terrain data for the State of Iowa. These hillshade maps are a derivative product from 1-meter resolution digital elevation models (DEM) from the LiDAR bare-earth datasets.

Clear Creek Data:

• Clear Creek DEM Hillshade Near IR U West - Near Infra-red (NIR) Lidar. Hillshade including canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Hillshade Near IR U East - Near Infra-red (NIR) Lidar. Hillshade including canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Hillshade Near IR F West - Near Infra-red (NIR) Lidar. Hillshade of topograpy without canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Hillshade Near IR F East - Near Infra-red (NIR) Lidar. Hillshade of topograpy without canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Hillshade Green Lidar F West - Green Lidar. Hillshade of topograpy without canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Hillshade Green Lidar F East - Green Lidar. Hillshade of topograpy without canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Near IR Lidar U West - Near Infra-red (NIR) Lidar. DEM including canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Near IR Lidar U East - Near Infra-red (NIR) Lidar. DEM including canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Near IR Lidar F West - Near Infra-red (NIR) Lidar. DEM of topography without canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Near IR Lidar F East - Near Infra-red (NIR) Lidar. DEM of topography without canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Green Lidar F West - Green Lidar. DEM of topography without canopy of western block in the watershed. QA/QC: By NCALM.

• Clear Creek DEM Green Lidar F East - Green Lidar. DEM of topography without canopy of eastern block in the watershed. QA/QC: By NCALM.

• Clear Creek CSD AQ 2015 - CZO Clear Creek IA - Waveform CSD Digitizer Data - CSD AQ 2015 Data.

• Clear Creek CSD AQ 2014 - Green Lidar. Raw Full Waveform Lidar. QA/QC: None.

• Clear Creek CSD NIR 2015 - CZO Clear Creek IA - Waveform CSD Digitizer Data - NIR 2015 Data.

• Clear Creek CSD NIR 2014 - Near Infra-red (NIR) Lidar. Raw Full Waveform Lidar. QA/QC: None.

• Clear Creek NIR - Near Infra-red (NIR) Lidar. Point Cloud data. QA/QC: By NCALM.

• Clear Creek AQ_532 - Green Lidar. Point Cloud data. QA/QC: By NCALM.

  GIS data in CCW - This dataset contains: * wss_gsmsoil_IA_[2006-07-06].zip = Soil data from SURRGO of the IA state * wss_SSA_IA095_soildb_IA_2003_[2016-09-22].zip = Soil data from SURRGO of watershed IA095. covers another half of CCW *. wss_SSA_IA103_soildb_IA_2003_[2016-09-22].zip = Soil data from SURRGO of watershed IA095. covers half of CCW * CCW_crop_cover_tif.zip = CCW crop cover in 2007 * ClearCreek_Streams.zip = Stream file for Clear Creek watershed in Iowa *. State_of_Iowa.zip = Shape file of the boundary of * ClearCreek_Border.zip = Shape file of the boundary of Iowa State QA/QC: Yes. * CCW 10 DEM - This dataset contains: * n42w093.zip = 10 meter resolution DEM at 42N 93W * n42w092.zip = 10 meter resolution DEM at 42N 92W * n42w091.zip = 10 meter resolution DEM at 42N 91W QA/QC: Yes. * CCW 1m lidar DEM - 1 meter resolution DEM for Clear Creek watershed QA/QC: Yes. * 2m Lidar DEM - 2 meter resolution DEM for Clear Creek watershed QA/QC: Yes.

Used by Districts to review structures clearance information that was captured by LiDAR as well as review where the measurement was taken.

This coverage contains selected arcs from the Iowa Stream Centerline coverage which was developed by the DNR and U of I IIHR. The selected arcs represent the centerlines of wide streams, impoundments, reservoirs, and wetlands as well as the segments of single line streams. Pseudonodes were removed from the Stream Centerline coverage so each segment went from confluence to confluence. Elevations for each node were obtained from the Iowa LiDAR DEM (2007-2010) data. The change in elevation between nodes was calculated and divided by the segment length to obtain the slope in m/m.

Two hydro-DEM versions available. Hydro elevation surface derived from Iowa lidar collected during 2007-2010. S-LibraryThe Iowa S-Library series of elevation data are watershed-scale, high-resolution rasters that have been hydro-conditioned and include some hydrologic enforcement. These data should be considered 'bare earth data' and are suitable for large scale examination of the landscape using a variety of terrain analysis methods and visualization techniques. Full metadata available here: https://acpfdata.gis.iastate.edu/ACPF/SLib2m_metadata.pdf

P-LibraryThe Iowa P-Library series of elevation data are watershed-scale, high-resolution rasters that have been hydro-conditioned to remove artifacts of the LiDAR collection process. These data should be considered 'bare earth data' and are suitable for large scale examination of the landscape using a variety of terrain analysis methods and visualization techniques. Full metadata available here: https://acpfdata.gis.iastate.edu/ACPF/PLib2m_metadata.pdf

Original Dataset Product: These are Digital Elevation Model (DEM) data for Wisconsin as part of the required deliverables for the WI_12County project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 2 foot hydro-flattened Raster DEM.

Original Dataset Geographic Extent: 4 counties in Wisconsin WI_12County_3 (Work Unit 300206) covering approximatel...

DRAFT Color hillshade digital surface model (DSM) from the 2020 LiDAR collection of Iowa.Similar to DEMs except that they may depict the elevations of the top surfaces of buildings, trees, towers, and other features elevated above the bare-earth. DSMs are especially relevant for telecommunications management, air safety, forest management, and 3D modeling and simulation.

(In progress)

2 Foot Contours of Iowa, Derived from LiDAR Data.

Full Metadata:

ftp://ftp.igsb.uiowa.edu/gis_library/ia_state/elevation/contours_2ft/contours_2ft.html