Data Management Plan

LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform.

Using a combination of laser range finding, GPS positioning and inertial measurement technologies; LIDAR instruments are

able to make highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures and vegetation.

Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 262 flight lines of high density (submeter ground

sample distance) data were collected over areas in Bay, Calhoun, Jackson and Washington Counties in Florida. This data set

was collected at the same time as the collection for Jefferson County, FL. Collectively, these data sets cover

approximately 1201 square miles. The data acquisition occurred in 17 missions between February 22, 2007 and March

13, 2007. Multiple returns were recorded for each laser pulse along with an intensity value for each return.

This data was collected at sub-meter resolution to provide average point spacing of 0.7 m for collected points. Up to

5 returns were recorded for each pulse in addition to an intensity value.

Original contact information:

Contact Name: John Crowe

Contact Org: Northwest Florida Water Management District (NWFWMD)

Phone: 850-539-5999

Email: john.crowe@nwfwmd.state.fl.us

Process Steps:

• 2007-02-22 00:00:00 - Data Collection: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 262 flight lines of high density (submeter ground sample distance) data were collected over areas in Bay, Calhoun, Jackson and Washington Counties in Florida. This data set was collected at the same time as the collection for Jefferson County, FL. Collectively, these data sets cover approximately 1201 square miles. The data acquisition occurred in 17 missions between February 22, 2007 and March 13, 2007. Multiple returns were recorded for each laser pulse along with an intensity value for each return. During the LIDAR campaign, the Sanborn field crew conducted a GPS field survey to establish final coordinates of the ground base stations for final processing of the base-remote GPS solutions. Four (4) airborne global positioning system (GPS) base stations were used to support the LiDAR data acquisition. GPS ground control check points were also collected by the LiDAR team while onsite for product accuracy validation and delivery.
• 2007-04-01 00:00:00 - Airborne GPS Processing: Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface for each flight line. The overlap between flight lines was removed to provide a homogeneous coverage, and the coverage was classified to extract a bare earth digital elevation model (DEM). Airborne GPS is differentially processed using the GrafNAV V7.50 software by Waypoint Consulting of Calgary, Alberta, Canada. The PDOP and distance separation is as follows: IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia. The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland.
• 2007-05-01 00:00:00 - IMU data Processing: IMU data provides information concerning roll, pitch and yaw of collection platform during collection event. IMU information allows the pulse vector to be properly placed in 3D space allowing the distance from the aircraft reference point to be properly positioned on the elevation model surface. IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada.
• 2007-06-01 00:00:00 - Reflective Surface Generation: The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia.
• 2007-10-01 00:00:00 - LIDAR Ground Point Classification: The classification and quality control (QC) of LiDAR Ground point class is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland. In the filtering process points are classified as Ground or one of several non-Ground classes including Unclassified, Overlap, and Low Points.
• 2007-11-01 00:00:00 - Reclassification of Water Points: LiDAR returns from open water surfaces are commonly included in the Ground class by the ground filtering algorithms. Using 2D and 3D visualization methods, 2D vector polygons were digitized for significant waterways and water bodies that were readily identifiable in the LiDAR data. These polygons were then used to re-classify points in open water from the filtered Ground class to the Water class.
• 2007-11-09 00:00:00 - Coordinate Reprojection: Output LAS Files LIDAR points maintained in UTM coordinate system converted to Geographic projection with units of Decimal Degrees
• 2008-07-21 00:00:00 - The NOAA Office for Coastal Management (OCM) received files in LAS format. The files contained LiDAR intensity and elevation measurements. OCM performed the following processing on the data to make it available within the LiDAR Data Retrieval Tool (LDART): 1. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03. 2. The LAS header fields were sorted by latitude and updated. 3. The data was filtered to eliminate outliers.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer

The data set is dynamically generated based on user-specified parameters.

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