Data Management Plan

Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1995 individual 1250 ft x 1250 ft tiles clipped to the DPA; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

Geographic Extent: LaPorte, Lake, and Porter counties in Indiana (and small portions of Cook County, Illinois and Berrien County, Michigan), covering approximately 112 square miles.

Dataset Description: The lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification 2021, Revision A. The data was developed based on a horizontal projection/datum of NAD83(HARN), Indiana West Feet, and vertical datum of NAVD88 (GEOID18) Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1995 individual 1250 ft x 1250 ft tiles clipped to the DPA, as tiled Intensity Images and tiled bare-earth DEMs; all tiled to the same 1250 ft x 1250 ft schema.

Ground Conditions: Lidar was collected in April 2022, while no snow was on the ground and rivers were at or below normal levels.

Sanborn Map Company, Inc. established a total of 25 accuracy check points, 20 in Bare Earth and Urban landcovers (20 NVA points), 5 in Tall Grass and Brushland/Low Trees categories (5 VVA points), that were used to assess the vertical accuracy of the data.

These data were received by the NOAA Office for Coastal Management (OCM) from the Indiana Dept. of Natural Resources (IN DNR). NOAA OCM processed the data to be available for custom and bulk downloads from the NOAA Digital Coast Data Access Viewer (DAV). In addition to the lidar point data, topobathy bare earth Digital Elevation Models (DEMs) at a 1 foot grid spacing, created from the lidar point data are also available from the NOAA Digital Coast. The link to these data and the hydro breaklines are provided in the URL section of this metadata record. Reports and hillshade rasters are available by request at coastal.info@noaa.gov.

Lineage Statement:
The Sanborn Map Company, Inc., collected lidar data for the Indiana (and small portions of the Illinois and Michigan) Lake Michigan coastline, for the Indiana Department of Natural Resources (IN DNR). The IN DNR provided the data to NOAA OCM for data distribution via the NOAA Digital Coast.

Process Steps:

• 2022-01-01 00:00:00 - The boresight was completed prior to project execution. The following steps describe the Raw Data Processing process: 1) Technicians processed the raw data to LAS format flight lines using the final GNSS/IMU solution. This LAS data set was used as source data for lidar matching. 2) Technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps match for the entire lift and adjusted as necessary until the results met the project specifications. 3) Once all lifts were completed with lidar matching, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSEz or within swath overlap (between adjacent swaths). 4) The technicians ran a final vertical accuracy check of the flight lines against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 2021, Revision A, and breaklines were collected for water features. Bare-earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening.
• 2022-01-01 00:00:00 - LAS Point Classification: The point classification is performed as described below. The bare-earth surface is then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is finalized, it is then used to generate all hydro-breaklines through heads-up digitization. All Class 2 (Ground) lidar data inside of the Lake Pond and Double Line Drain hydro-flattened breaklines were then classified to Class 9 (Water) using LP360 functionality. A buffer of 1 ft was also used around each hydro-flattened feature to classify these Class 2 (Ground) points to Class 20 (Ignored Ground). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the Class 2 (Ground) points were reclassified to the correct classification after the automated classification was completed. All data was manually reviewed and any remaining artifacts removed using functionality provided by LP360, TerraScan and TerraModeler. Global Mapper was used as a final check of the bare-earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files. Sanborn Map Company, Inc. proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information.
• 2022-01-01 00:00:00 - Data was tested at 0.29 meter aggregate nominal pulse spacing and at 12.0 aggregate points per meter. The aggregate nominal pulse spacing was tested on classified tiled LAS using geometrically reliable first-return points. ANPS was tested using Delaunay Triangulation that produced average point spacing between all nearest neighbors.
• 2023-02-17 00:00:00 - The NOAA Office for Coastal Management (OCM) received 1995 las files from the Indiana DNR for the Indiana (and small portion of Illinois) Lake Michigan coastline. The lidar data had elevation and intensity measurements. The data were in Indiana State Plane West coordinates (NAD83 HARN), US survey feet and NAVD88 (Geoid18) elevations in US survey feet. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 17 - Bridge Decks, 18 - High Noise, 20 - Ignored Ground. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 7, 9, 17, 18, 20. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 2. Internal OCM scripts were run on the las files to convert from Indiana State Plane West coordinates (NAD83 HARN), US survey feet to geographic coordinates, to convert from NAVD88 (Geoid18) elevations in feet to ellipsoidal elevations in meters, to assign the geokeys, to sort the data by gps time and zip the data to database and to AWS S3.

Data is available online for bulk and custom downloads.

Data is backed up to tape and to cloud storage.