Aerial Services, Inc.20190104Lidar point cloudProduct: These lidar data are processed Classified LAS 1.4 files, formatted to 22,028 individual 2000 foot x 2000 foot tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: West Central Illinois, covering approximately 3,077 square miles. Counties included are Schuyler, Brown, Menard, Mason, Sangamon, and Morgan. A lidar survey was collected over two (2) areas of interest (AOI) in Illinois identified as the Base AOI and the Option AOI. The Base AOI covers approximately 1,926 square miles in total and the Option AOI covers approximately 1,151 square miles for a total of 3,077 square miles. Dataset Description: West Central Illinois 2017 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.5 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2; Quality Level 2+. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane Coordinate System Illinois West (FIPS 1202), US Survey Feet and vertical datum of NAVD88 (GEOID12B), US Survey Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 22,208 individual 2000 foot x 2000 US survey feet tiles, as 22,208 tiled Intensity Imagery, and as 22,209 tiled bare earth DEMs; all tiled to the same 2000 foot x 2000 foot schema. In an effort to preserve smooth continuity of the surface in which there are multiple overlapping swaths, an isolated area of cross flight line 229 was bit set at withheld in the following nine tiles: 2207_1295, 2207_1293, 2209_1297, 2209_1295, 2209_1293, 2311_1297, 2311_1295, 2311_1293, and 2313_1297. One tile located in Mason County, titled 2353_1367, did not contain LAS points as it consisted strictly of water with no ground points present. Therefore, no intensity image TIF could be produced for this tile, only a hydro-flattened DEM image is available. This tile is included in the tile index consisting of 22,209 tiles. Ground Conditions: Lidar was collected in December 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Surveying and Mapping, LLC (SAM) established a total of 63 ground control points that were used to calibrate the lidar to known ground locations established throughout the Base AOI and Option AOI project areas. An additional 162 independent accuracy checkpoints, 91 in Bare Earth and Urban landcovers (91 NVA points), 71 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (71 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.To acquire QL2+ lidar detailing surface elevation data, vegetation, and buildings for use to support the 3DEP mission, the Natural Resources Consevation Services (NRCS) Agricultural Drainage Water Management Initiative, National Water Quality Initiative and the Mississippi River Basin Initiative. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 US survey feet cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.USGS Contract No. G17PD01203 CONTRACTOR: Aerial Services, Inc. Lidar data were acquired and calibrated by the prime contractor. SUBCONTRACTOR: Tetra Tech manually edited bare earth surface and building rooftop cleanup, preformed hydro collection, flattening, produced bare earth DEMs for 2/3 of the project area. All follow-on processing was completed by the prime contractor. USGS-NGP Base Lidar Specification v1.4Leica ALS70-HP40.540.541300110504719751.50106410.29121230National Geodetic Survey (NGS) Geoid12B0.184660.12247910.12256910.17489711.46Withheld (ignore) points were identified in these files using the standard LAS witheld bit.Swath "overage" points were identified in these files using the standard LAS overlap bit161Processed, but Unclassified2Bare Earth Ground3Low Vegetation4Medium Vegetation5High Vegetation6Building7Low Noise9Water10Ignored Ground17Bridge Decks18High Noise2017120320171213Ground ConditionCompleteNone Planned-90.91799-89.2163540.4368139.518061161653114725923638972278654NoneModelLAS Point CloudRemote SensingElevation DataLidarNoneIllinoisSchuyler CountyBrown CountyMenard CountyMason CountySangamon CountyMorgan CountyNo restrictions apply to these data.None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.Data covers the entire area specified for this project.These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.The specifications require that only nonvegetated vertical accuracy (NVA) be computed for raw lidar data swath files. The vertical accuracy was tested with 91 independent survey located in open terrain. These check points (check points) were not used in the calibration or post processing of the lidar data. The survey check points were distributed throughout the project. Specifications for this project require that the NVA be 19.6 centimeters (cm) or better AccuracyZ at 95-percent confidence level. 0.12256The NVA was tested using 91 independent survey located in open terrain. The survey check points were distributed throughout the project area. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control. The root mean square error vertical (RMSEz) was computed to be 0.06253 meters. AccuracyZ has been tested to meet 19.6 cm NVA at 95-percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using American Society of Photogrammetry and Remote Sensing (ASPRS) Guidelines.LAS Point Classification QL2+: The point classification was performed as described below. Classification Filters were applied to aid in the definition of; terrain characteristics, vegetation attribution of low, medium or high and building roof tops. Filtering processes address aspects of the data such as: ground points, noise points, air points, low points, Low vegetation 0.5-5’, medium vegetation 5-20’, high vegetation >20’, manmade features, buildings, and overlap points. The Classified point cloud data was manually reviewed to ensure correct classification of; ground (ASPRS class 2), and building roof tops (ASPRS class 6). After the bare earth surface was finalized, it was then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS class 2) lidar data inside of the Inland Ponds and Lakes, and Inland Streams and Rivers are classified to water (ASPRS class 9). A buffer of 2.5 feet was used around each hydro-flattened feature to classify ground (ASPRS class 2) to ignored ground (ASPRS class 10). Island features were checked to ensure that Ground point (ASPRS class 2) remained classified as Ground. Ground points (ASPRS class 2) within 2.5 feet of bridge breaklines, used to reduce triangulation between bridge decks were also classified to Ignored ground (ASPRS class 10). All bridge decks were classified to Bridge deck (ASPRS class 17). All remaining points were filtered, or manually classified to their respective point classification; processed (ASPRS class 1), low vegetation (ASPRS class 3), medium vegetation (ASPRS class 4), high vegetation (ASPRS class 5), buildings (ASPRS class 6), low noise (ASPRS class 7), high noise (ASPRS class 18). TerraScan v20.07.2018 was used to identify the overlap flag and bit set flags to LAS v1.4 specifications. LP360 64bit was used to deduce the Well Known Text (WKT) and an ASI proprietary software was used to format the LAS to the final LAS v1.4 Format 6 version. LAStools by rapidlasso GmbH, open source, lasvalidate, lasread v1.1 and a ASI proprietary software was used to perform final analysis to checks on LAS header information, LAS point classes, and LAS timestamps.20181220PointState Plane Coordinate System 1983NAD 1983 2011 Illinois West State Plane (FIPS 1202)0.999941-90.1666666736.666666677000000.0coordinate pair0.010.01US Survey FeetNorth American Datum of 1983 2011Geodetic Reference System 19806378137298.25722210North American Vertical Datum of 19880.01US survey feetExplicit elevation coordinate included with horizontal coordinates20190104Aerial Services, Inc.mailing and physical

6315 Chancellor Dr.

Cedar FallsIA50613USA(319)277-0436FGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998To acquire QL2+ lidar detailing surface elevation data, vegetation, and buildings for use to support the 3DEP mission, the Natural Resources Consevation Services (NRCS) Agricultural Drainage Water Management Initiative, National Water Quality Initiative and the Mississippi River Basin Initiative. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 US survey feet cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.<DIV STYLE="text-align:Left;"><DIV><P><SPAN>Product: These lidar data are processed Classified LAS 1.4 files, formatted to 22,028 individual 2000 foot x 2000 foot tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: West Central Illinois, covering approximately 3,077 square miles. Counties included are Schuyler, Brown, Menard, Mason, Sangamon, and Morgan. A lidar survey was collected over two (2) areas of interest (AOI) in Illinois identified as the Base AOI and the Option AOI. The Base AOI covers approximately 1,926 square miles in total and the Option AOI covers approximately 1,151 square miles for a total of 3,077 square miles. Dataset Description: West Central Illinois 2017 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.5 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2; Quality Level 2+. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane Coordinate System Illinois West (FIPS 1202), US Survey Feet and vertical datum of NAVD88 (GEOID12B), US Survey Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 22,208 individual 2000 foot x 2000 US survey feet tiles, as 22,208 tiled Intensity Imagery, and as 22,209 tiled bare earth DEMs; all tiled to the same 2000 foot x 2000 foot schema. In an effort to preserve smooth continuity of the surface in which there are multiple overlapping swaths, an isolated area of cross flight line 229 was bit set at withheld in the following nine tiles: 2207_1295, 2207_1293, 2209_1297, 2209_1295, 2209_1293, 2311_1297, 2311_1295, 2311_1293, and 2313_1297. One tile located in Mason County, titled 2353_1367, did not contain LAS points as it consisted strictly of water with no ground points present. Therefore, no intensity image TIF could be produced for this tile, only a hydro-flattened DEM image is available. This tile is included in the tile index consisting of 22,209 tiles. Ground Conditions: Lidar was collected in December 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Surveying and Mapping, LLC (SAM) established a total of 63 ground control points that were used to calibrate the lidar to known ground locations established throughout the Base AOI and Option AOI project areas. An additional 162 independent accuracy checkpoints, 91 in Bare Earth and Urban landcovers (91 NVA points), 71 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (71 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.</SPAN></P></DIV></DIV>IL_West_Central_Lidar_2017_D17; Classified LAS 1.4ModelLAS Point CloudRemote SensingElevation DataLidar<DIV STYLE="text-align:Left;"><DIV><P><SPAN>None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.</SPAN></P></DIV></DIV>15000000050001.0FGDC2019041514021800FGDC CSDGM MetadataTRUEfile://\\isgs-terrain\distribution\counties\mason\morgan_2017_metadataLocal Area Networkknown Calls 1. The “Boundary, Bridges, Inland_Lake_Pond, Inland_Stream_River, Island_Polygon, and Island_Polyline” break line feature classes somehow have the horizontal datum with the wrong unit of measurement, meters instead of feet, in the Z information. (It should be NAVD88 ft us) 2. The GCP, NVA, and VVA checkpoint shapefiles are not Z enabled, and as a result have no vertical datum information 3. The metadata states that 4 tiles in Mason County have points with the withheld flag, but upon examination those 4 tiles do not have any point with the withheld flag nor do any other tiles in the county (It appears to be a metadata issue with the actual tiles residing in Schuyler County) 4. The breaklines on two lakes are out of tolerance 5. There is smoke and steam from a power plant that should have been classified as noise 6. There are several instances where structures or vegetation have been misclassified as ground 7. There is a sporadic issue of points in one of the advanced classifications, i.e. points that represent structures, trees, etc., being misclassified into one of the other classes