Data Management Plan (Deprecated)

This record describes Light Detection and Ranging (Lidar) data acquired for the island of Puerto Rico. The data were acquired for

USACE, St. Louis District by 3001, Inc., between January 10 and February 8, 2004. The mission was flown at a density sufficient to support

a maximum final post spacing of 6 feet for unobscured areas. The Puerto Rico LiDAR Survey was collected under the guidance of a

Professional Mapper/Surveyor.

Original contact information:

Contact Org: 3001, Inc.

Title: LiDAR Department

Phone: (985) 661- 3001

Email: lidar@3001inc.com

Process Steps:

• 2007-01-01 00:00:00 - The ABGPS, inertial measurement unit (IMU), and raw scans are collected during the LiDAR aerial survey. The ABGPS monitors the xyz position of the sensor and the IMU monitors the orientation. During the aerial survey laser pulses reflected from features on the ground surface are detected by the receiver optics and collected by the data logger. GPS locations are based on data collection receivers on the aircraft and base stations on the ground. The ground base stations are placed no more than 35 km radius from the flight survey area.
• 2007-01-01 00:00:00 - The ABGPS, IMU, and raw scans are integrated using proprietary software developed by the Leica Geosystems and delivered with the Leica ALS50 System. The resultant file is in a LAS binary file format. The LAS file version 1.0 format can easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return#, intensity value, xyz, etc.). The resultant points are produced in the State Plane Puerto Rico FIPS 5200 coordinate system, with units in feet and referenced to the NAD83 horizontal datum and NAVD88 vertical datum.
• 2007-01-01 00:00:00 - The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters is applied as appropriate for the production of bare-earth digital terrain models (DTMs). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces.
• 2007-01-01 00:00:00 - Filtered and edited data are subjected to rigorous QA/QC according to the 3001 Inc. Quality Control Plan and procedures. Very briefly, a series of quantitative and visual procedures are employed to validate the accuracy and consistency of the filtered and edited data. Ground control is established by 3001, Inc. and GPS-derived ground control points (GCPs) points in various areas of dominant and prescribed land cover. These points are coded according to landcover, surface material and ground control suitability. A suitable number of points are selected for calculation of a statistically significant accuracy assessment as per the requirements of the National Standard for Spatial Data Accuracy. A spatial proximity analysis is used to select edited LiDAR data points within a specified distance of the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative error and adequate sample size. Accuracy validation and evaluation is accomplished using proprietary software to apply relevant statistical routines for calculation of Root Mean Square Error (RMSE) and the National Standard for Spatial Data Accuracy (NSSDA) according the Federal Geographic Data Committee (FGDC) specifications.
• 2007-01-01 00:00:00 - The LiDAR mass points were delivered in ASPRS LAS 1.0 format. The header file for each dataset is complete as defined by the LAS 1.0 specification. The LAS files do not include overlap. The delivered tiles are suitable for seamless topographic data mosaics that include no "no data" areas. The names of the tiles are left padded with zeros as required to achieve a five character length and all files utilize the LAS file extension.
• 2010-12-07 00:00:00 - The NOAA Office for Coastal Management (OCM) received the files in las format. The files contained Lidar elevation and intensity measurements. The data were in projected in Puerto Rico State Plane Coordinates (FIPS 5200/NAD83), and referenced to the orthometric datum of NAVD88 utilizing Geoid 99. Both planar and vertical units were measured in feet. OCM performed the following processing to the data to make it available within the Digital Coast: 1. The data were converted from State Plane Coordinates (NAD83; ft) to UTM coordinates (Zone 20/NAD83; m). 2. The vertical units of the data were converted from NAVD88 (ft) to NAVD88 (m). 3. The data were re-tiled using MARS software. 4. The data were reclassified such that all classifications were set to Class 0. 5. The data were filtered to Bare Earth (Class 2) and Unclassified (Class 1) using an automated process in LASEdit. 6. The data were converted from UTM coordinates (Zone 20/NAD83) to geographic coordinates (NAD83) and ellipsoidal elevations (GRS80) using Geoid 99. 7. The LAS data were sorted by latitude and the headers were updated.