Identification_Information: Citation: Citation_Information: Originator: Aero-Metric, Inc. Publication_Date: 20060412 Title: Dodge County, Wisconsin - LiDAR Data Geospatial_Data_Presentation_Form: remote-sensing image Description: Abstract: Dodge County, Wisconsin Purpose: The Dodge County LiDAR elevation data is to provide high accuracy bare-earth processed LiDAR data for the defined terrain located in Dodge County, Wisconsin. The project consisted of acquisition, post-processing, and classification of LiDAR data. The classified bare-earth data achieves the following: nominal horizontal spacing of 3 feet based on the Wisconsin County Coordinate System, Dodge County, related to the North American Datum of 1983/1997. Vertical accuracy was to support the capability of generating 2 ft contours relative to the North American Vertical Datum of 1988. The vertical accuracy testing methods derived from the NSSDA/FEMA and NDEP/ASPRS guidelines, when applied to the Dodge County project, verify that the digital vertical data provided by AME is well suited for the production of 2 ft contours. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20060412 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: unknown Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -89.010829 East_Bounding_Coordinate: -88.399516 North_Bounding_Coordinate: 43.633655 South_Bounding_Coordinate: 43.194652 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Light Detection and Ranging Theme_Keyword: LiDAR Place: Place_Keyword_Thesaurus: None Place_Keyword: Dodge County Place_Keyword: Wisconsin Access_Constraints: None Use_Constraints: None Data_Set_Credit: AERO-METRIC, INC. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Logical_Consistency_Report: Completeness_Report: Complete Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The data was acquired at 3600 feet above mean terrain (AMT) and produced a horizontal accuracy of 1.8 feet, with a nominal point spacing of 3.0 feet. The LiDAR data was additionally checked against ortho images to ensure horizontal accuracy. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The LIDAR data as tested according to NSSDA achieved a vertical accuracy of 0.201 feet RMSE. The LiDAR data was further tested according to FEMA/NSSDA achieving a vertical accuracy of 0.37 RMSE. Lineage: Process_Step: Process_Description: The LiDAR data was captured using AERO-METRIC's twin-engine Cessna 320 equipped with a LiDAR system. The LiDAR system includes a differential GPS unit and inertial measurement system to provide superior accuracy. Acquisition parameters: 1. Scanner - Optech ALTM 30/70 2. Flight Height - 3600 feet above mean terrain 3. Swath Width - 38 degrees 4. Sidelap - 30% 5. Nominal Post Spacing - 3 feet GPS and IMU processing parameters: 1. Processing Programs and version - Applanix - POSGPS and POSProc, versions 4.3 2. Number of base stations during LiDAR collection - 3 (2W29, 3W34, and JUNEAU or UNU A) 3. Max separation between base stations during LiDAR collection - 0.13m 4. IMU processing monitored for consistency and smoothness - Yes. Point Cloud Processing: 1. Program and version - REALM 3.5.3 2. Horizontal Datum - NAD83/97 3. Horizontal Coordinates - Wisconsin County Coordinates, Dodge County 4. Vertical Datum - NAVD88 5. Geoid Model used to reduce satellite derived elevations to orthometric heights - NGS Geoid03. LIDAR Processing: 1. Processing Programs and versions - TerraSolid TerraScan (version 006.0008) and TerraMatch (version 006.004) and Intergraph MicroStation (version.08.01.02.15). 2. Point Cloud data is imported to TerraScan in a Microstation V8 (V) CAD environment on a specified 5000 feet by 5000 feet tiling scheme. 3. Analyze the data for overall compleness and consistency. This is to ensure that there are no voids in the data collection. 4. Inspect for calibration errors in the dataset using the TerraMatch software. This is accomplished by sampling the data collected accross all flight lines and classify the idividual lines to ground. The sofware will use the ground-classified lines to compute corrections (Heading, Pitch, Roll, and Scale). 5. Orientation corrections are then applied to the entire dataset. 6. Automatic ground classification is performed using algorithms with customized parameters to best fit the project area. Several areas of varying relief and planimetric features were inspected to verify the final ground surface. 7. Bloom Consultants provided Quality Assurance and Quality Control (QAQC) data for this project. Bloom Consultants captured 480 QA/QC points spread throughout the project area were used to test the accuracy of the LiDAR ground surface. TerraScan's Output Control Report (OCR) was used to compare the QAQC data to the LIDAR data. This routine searches the LIDAR dataset by X & Y coordinate, finds the closest LIDAR point and compares the vertical (Z) values to the known data collected in the field. Based on the QAQC data, a bias adjustment of -0.200 feet was determined, and the results were applied to the LIDAR data. A final OCR was performed with a resulting RMSE of 0201 feet was achieved. 8. Once the automatic processing and the testing of LiDAR is complete, AERO-METRIC meticulously reviews the generated bare-earth surface data to insure that proper classification was achieved as part of a Quality Control process. 9. Final deliverable are generated. 10. In support of verifying the accuracy according to FEMA/NSSDA guidelines, Dodge County provided 105 supplemental points in the 5 land cover categories. Overall the points achieved a 0.72 feet at a 95% confidence according to FEMA/NSSDA testing guidelines. Please see Vertical Accuracy Assessment Report for more detail. Final Deliverables: 1. One paper and CD digital copy of theControl Report. 2. One Firewire containing the following: Bare Earth LIDAR in ASCII format (x,y,z) - comma delimited. x=Easting (0.001 resolution), y=Northing (0.001 resolution), z=Elevation (0.001 resolution) Process_Date: 200611 Cloud_Cover: unknown Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: other grid system Other_Grid_System's_Definition: Dodge County Coordinates Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.001 Ordinate_Resolution: 0.001 Planar_Distance_Units: Survey Feet Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983/1997 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Resolution: .001 Altitude_Distance_Units: Survey Feet Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Attributes present in the data set (e.g. X