Data Management Plan

Product: These lidar data are processed classified LAS 1.4 files, formatted to 1,710 individual 5,000-foot x 5,000-foot tiles; used to create intensity images, 3D breaklines, hydro-flattened DEMs, building footprints, and contours as necessary.

Geographic Extent: Partial coverage of eastern San Diego County in southwestern California, covering approximately 1,353 total square miles.

Dataset Description: The Eastern San Diego County, California 2017 QL2 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 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane California Zone VI, US survey feet and vertical datum of NAVD88 (GEOID12B), US survey feet. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 1,710 individual 5,000-foot x 5,000-foot pilot tiles; as tiled intensity imagery, and as tiled bare earth DEMs, all tiled to the same schema. Continuous breaklines were produced in Esri file geodatabase format. Building footprints were produced in Esri file geodatabase format. Tiled contours with a 2-foot interval were produced in Esri file geodatabase format.

Ground Conditions: Lidar was partially collected in fall/winter of late 2016/early 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, Quantum Spatial, Inc. established a total of 28 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 116 independent accuracy checkpoints, 64 in Bare Earth and Urban landcovers (64 NVA points), 52 in the Forest, Shrubs, and Tall Weeds category (52 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

Process Steps:

• 2017-01-01 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 ground (ASPRS Class 2) lidar data inside of the Lake Pond and Double Line Drain hydro-flattened breaklines were then classified to Water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 3 feet was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). 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. Buildings were classified to Class 6. All bridge decks were classified to Class 17. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS through numerous conference calls and pilot study areas. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper us used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Quantum Spatial, 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.
• 2018-10-04 00:00:00 - Data were obtained by NOAA/OCM from USGS ftp site ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects /USGS_LPC_CA_E_SanDiegoCo_2016_LAS_2017/. For ingestion into the Digital Coast Data Access Viewer, the following changes were made. 1) horizontal reprojection from California State Plane VI (FIPS 0406) to geographic coordinates 2) vertical units change from feet to meters 3) reduction to vertical NAD83(2011) ellipsoid heights by removing the GEOID12B model.

Data is available online for custom downloads