Data Management Plan

Product: Calibrated LiDAR version 1.4 .las tiles, classified to bare earth for subsequent derivatives.

Geographic Extent: Erie, Genesee, and Livingston Counties, New York, covering approximately 2,188 square miles.

Dataset Description: Erie, Genesee, and Livingston Counties, New York 2019 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. Project specifications are based on the USGS LIDAR Base Specifications Version 1.3. The data was developed based on a horizontal projection/datum of NAD83(2011), Conus Albers, meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 5667 individual 1000 m x 1000 m tiles, as tiled bare earth DEMs; all tiled to the same 1000 m x 1000 m schema.

Ground Conditions: Lidar was collected in the spring 2019, 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, New York Office of Information Technology Services provided a total of 44 ground control points that were used to calibrate the lidar to known ground locations established throughout the Erie, Genesee, and Livingston Counties, New York project area. An additional 214 checkpoints, 111 NVA in Bare Earth and Urban landcover and 103 VVA in Tall Grass and Brushland/Low Trees categories were surveyed by Axis Geospatial, LLC to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. 4 of the 111 NVA checkpoints fell beyond the contracted project limits and were not used for the NVA assessment of the DEMs but were used for the NVA assessment of the swaths.

Process Steps:

• 2019-01-01 00:00:00 - LAS Point Classification: The point classification is performed as described below. The bare earth surface was manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface was finalized, breaklines for hydrography and underneath bridges were digitized. Hydro breaklines were compiled for rivers and streams over 30 m wide and for lakes and ponds greater than 2 acres in area then utilized to generate hydro-flattened water features for the DEMs. The bridge terrain breaklines were captured at the bridge deck level and below along the ground beneath to allow proper flow of hydro through bridges per USGS “LIDAR Base Specification, Version 1.3”. All breaklines were delivered as 3D ESRI shapefiles with attribution for feature types. All ground (ASPRS Class 2) lidar data inside of hydro-breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro-breakline feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to appropriately bit flag overlapping flight line data per USGS specifications. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper was used as a final check of the bare earth dataset. LP360 was then used to create the deliverable industry-standard LAS files for both the Raw Swath Data and the Classified Tiles. New York Office of Information Technology Services 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.
• 2020-10-20 00:00:00 - The NOAA Office for Coastal Management (OCM) downloaded this data set from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/NY_3County_2019_A19/ Metadata was retrieved from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/NY_3County_2019_A19/NY_3County_2019/ The number of files downloaded and processed was 5518. The data were in Albers CONUS (NAD83 2011) coordinates in meters and NAVD88 (Geoid12b) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 17 - Bridge Decks, 18 - High Noise, 20 - Ignored Ground. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). 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 laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid12b model, to convert from Albers CONUS (NAD83 2011) coordinates in meters to geographic coordinates, to assign the geokeys, to sort the data by gps time and zip the data to database and to http.

Data is available online for bulk or custom downloads

Data is backed up to tape and to cloud storage.