Data Management Plan

Aerial Cartographics of America (ACA) collected 2233 square miles in the New York counties of Chautauqua, Orleans, Wayne, Cayuga, Jefferson, Oswego and St. Lawrence. The nominal pulse spacing for this project was no greater than 0.7 meters. Dewberry used proprietary procedures to classify the LAS into an initial ground surface. Dewberry then used proprietary procedures to classify the LAS and performed manual classifications according to project specifications: 1-Unclassified, 2-Ground, 7-Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 11- Witheld. The LiDAR data were processed to a bare-earth digital terrain model (DTM). Detailed breaklines and bare-earth Digital Elevation Models (DEMs) were produced for the project area. Deliverables were produced in NAD83 (2011) UTM Zone 18, meters and NAVD88 (geoid 12a), meters. The data was formatted according to the USNG Tile naming convention with each tile covering an area of 1,500 meters by 1,500 meters.

The NOAA Office for Coastal Management (OCM) downloaded:

2344 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_GreatLakes_Phase2_L3_2014_LAS_2017/

218 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_FEMA_R2L1_ChautauquaCo_2014_LAS_2017/

507 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_FEMA_R2L2_OrleansCo_2014_LAS_2017/ (Two files from this source were later determined to be corrupt and were removed from the the NOAA OCM Data Access Viewer (DAV) database and the bulk download AWS S3 site. Valid files were downloaded from the Discover GIS Data NY site (https://orthos.dhses.ny.gov/) and processed to provide a complete dataset).

and processed the data to the Data Access Viewer (DAV) and https. OCM noted that along the Chautauqua and Orleans County shoreline, there are points that fall in Lake Erie and Lake Ontario that are classified as ground.

Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

Lineage Statement:
The laz files for this dataset were downloaded mainly from the USGS rockyweb site: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/FEMA_Region_2_NY_Great_Lakes_Area_QL2_LiDAR/. Two files from this source in the Orleans County part of the dataset were determined to be corrupt. Those files were deleted from the NOAA OCM Data Access Viewer (DAV) database and the bulk download AWS S3 site. Valid versions of the two corrupt files were downloaded from the Discover GIS Data NY site (https://orthos.dhses.ny.gov/) and processed to provide a complete dataset for custom and bulk downloads.

Process Steps:

• Data for the New York Great Lakes LiDAR project was acquired by Aerial Cartographics of America, Inc. using a CESSNA TU206G aircraft. The project area included approximately 2233 contiguous square miles for New York. LiDAR sensor data was collected with the RIEGL LMS-Q680i LiDAR system and RIEGL LMS-Q780i LiDAR system. No imagery was requested or delivered. The calibrated data was processed to NAD83(2011) UTM 18, meters, NAVD88 (Geoid12A), meters. Deliverables for the project included a raw (unclassified) calibrated LiDAR point cloud, survey control, and a final control report. A preliminary RMSEz error check is performed at this stage of the project life cycle in the raw LiDAR dataset against GPS static and kinematic data and compared to RMSEz project specifications. The LiDAR data is examined in open, flat areas away from breaks. Lidar ground points for each flightline generated by an automatic classification routine are used. Overall the LiDAR data products collected by ACA meet or exceed the requirements set out in the Statement of Work. The quality control requirements of ACAs quality management program were adhered to throughout the acquisition stage fo this project to ensure product quality. LIDAR acquisition began on May 5, 2014 (julian day 125) and was completed on October 27, 2015 (julian day 300). A total of 28 survey missions were flown to complete the project. ACA utilized a CESSNA TU206G for the acquisition. The flight plan was flown as planned with no modifications. There were no unusual occurrences during the acquisition and the sensor performed within specifications. There were 455 flight lines required to complete the project. The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile any data if not complete. Subsequently the mission points are output, initially with default values from Riegl or the last mission calibrated for system. The initial point generation for each mission calibration is verified within Microstation/Terrascan for calibration errors. If a calibration error greater than specification is observed within the mission, the roll pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are regenerated and validated internally once again to ensure quality. All missions are validated against the adjoining missions for relative vertical biases and collected GPS validation points for absolute vertical accuracy purposes. On a project level, a supplementary coverage check is carried out to ensure no data voids unreported by Field Operations are present. The initial points for each mission calibration are inspected for flight line errors, flight line overlap, slivers or gaps in the data, point data minimums, or issues with the LiDAR unit or GPS. Roll, pitch and scanner scale are optimized during the calibration process until the relative accuracy is met. Relative accuracy and internal quality are checked using at least 3 regularly spaced QC blocks in which points from all lines are loaded and inspected. Vertical differences between ground surfaces of each line are displayed. Color scale is adjusted so that errors greater than the specifications are flagged. Cross sections are visually inspected across each block to validate point to point, flightline to flightline and mission to mission agreement. For this project the specifications used are as follow: Relative accuracy <= 7cm RMSEZ within individual swaths and <=10 cm RMSEZ or within swath overlap (between adjacent swaths). UTM coordinate system, meters, zone 18, horizontal datum NAD83 (2011), vertical datum NAVD88, Geoid 12A
• 2015-12-01 00:00:00 - Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All LiDAR related processes begin by importing the data into the GeoCue task management software. The swath data is tiled according to project specifications (1,500 m x 1,500 m). The tiled data is then opened in Terrascan where Dewberry uses proprietary ground classification routines to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. Once the ground routine has been completed a manual quality control routine is done using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review and supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification corrections were completed, the dataset was processed through a water classification routine that utilizes breaklines compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points that are within 0.3 meter of the hydrographic features are moved to class 10, an ignored ground due to breakline proximity. In addition to classes 1, 2, 9, and 10, there is a Class 7, noise points and Class 11, withheld . Class 7 was only used if needed when points could manually be identified as low/high points and class 11 points are points that contain a scan angle greater than 20 degrees. The fully classified dataset is then processed through Dewberry's comprehensive quality control program. The data was classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 7= Noise Class 9 = Water Class 10=Ignored Class 11= Withheld The LAS header information was verified to contain the following: Class (Integer) GPS Week Time (0.0001 seconds) Easting (0.003 m) Northing (0.003 m) Elevation (0.003 m) Echo Number (Integer 1 to 4) Echo (Integer 1 to 4) Intensity (8 bit integer) Flight Line (Integer) Scan Angle (Integer degree)
• 2019-06-04 00:00:00 - The NOAA Office for Coastal Management (OCM) downloaded: 2344 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_GreatLakes_Phase2_L3_2014_LAS_2017/ 218 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_FEMA_R2L1_ChautauquaCo_2014_LAS_2017/ 507 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_NY_FEMA_R2L2_OrleansCo_2014_LAS_2017/ The data were in UTM Zone 18 North (NAD83 2011) coordinates and NAVD88 (Geoid12A) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 11 - Withheld (Points with scan angles exceeding +/- 20 degrees). OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 3, 7, 9, 10, 11. OCM noted that along the Chautauqua and Orleans County shoreline, there are points that fall in Lake Erie and Lake Ontario that are classified as ground. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. The LAStools software scripts lasinfo and lasvalidate were run on the laz files to check for errors. 2. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 3. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12A model, to convert from UTM Zone 18 North (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.
• 2023-09-28 00:00:00 - In September of 2023, two of the laz files in the Orleans County portion of this dataset were determined to be corrupt. The files were corrupt from the source, which was the USGS rockyweb site. USGS was notified of the issue. The two corrupt files were deleted from the NOAA OCM Data Access Viewer (DAV) database and the AWS S3 bulk download site. The two corrupt files were: 17TQH390810 and 17TQH555870. Valid replacement versions of the two corrupt files were downloaded from the Discover GIS Data NY lidar download site at: https://orthos.dhses.ny.gov The data were in UTM Zone 18 North (NAD83 2011) coordinates and NAVD88 (Geoid12A) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 11 - Withheld (Points with scan angles exceeding +/- 20 degrees). OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 3, 7, 9, 10, 11. OCM noted that along the Orleans County shoreline, there are points that fall in Lake Ontario that are classified as ground. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. The LAStools software scripts lasinfo and lasvalidate were run on the laz files to check for errors. 2. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 3. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12A model, to convert from UTM Zone 18 North (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 AWS S3.

Data is available online for bulk and custom downloads.