Data Management Plan

This task is issued under USGS Contract No. G10PC00057, Task Order No. G15PD00091. This task order requires lidar data to be acquired over approximately 5981 square miles. The lidar was collected and processed to meet a maximum Nominal Post Spacing (NPS) of 0.7 meter. The NPS assessment is made against single swath, first return data located within the geometrically usable center portion (typically ~90%) of each swath.

The data was collected using a Leica ALS70 500 kHz Multiple Pulses in Air (MPiA) lidar sensor and a Chiroptera II sensor.

The ALS70 sensor collects up to four returns per pulse, as well as intensity data, for the first three returns. If a fourth return was captured, the system does not record an associated intensity value.

The Chiroptera II sensor provides 35 kHz bathymetric data and up to 500 kHz topographic data. The system acquires bathymetric lidar, topographic lidar and 4-band 80 MP digital camera imagery simultaneously. For this project, the flight parameters were used to provide 100% coverage. Two multiple pulse in air zones were used.

The Coastal delivery was processed and projected in Mississippi State Plane East Zone, NAD83(2011). The vertical datum used for the task order was referenced to NAVD88, GEOID12A/12B in units of US Survey Feet. These data were converted to geographic coordinates with elevation in meters above the ellipsoid for ingest into the NOAA Digital Coast. Further projection and datum processing may have occurred (see process descriptions).

Process Steps:

• 2015-01-01 00:00:00 - All airborne GNSS and IMU data was post-processed and quality controlled using Applanix MMS software. GNSS data was processed at a 1 and 2 Hz data capture rate and the IMU data was processed at 200 Hz. Position and orientation data were acquired in the aircraft using a NovAtel SPAN with LCI-100C IMU. All data were post-processed using NovAtel Inertial Explorer software to provide a tightly-coupled kinematic position and orientation solution.
• 2015-01-01 00:00:00 - When the sensor calibration, data acquisition, and GPS processing phases were complete, the formal data reduction processes by Woolpert lidar specialists included: - Processed individual flight lines to derive a raw "Point Cloud" LAS file. Matched overlapping flight lines, generated statistics for evaluation comparisons, and made the necessary adjustments to remove any residual systematic error. - Calibrated LAS files were imported into the task order tiles and initially filtered to create a ground and non-ground class. Then additional classes were filtered as necessary to meet client specified classes. - Once all project data was imported and classified, survey ground control data was imported and calculated for an accuracy assessment. As a QC measure, Woolpert has developed a routine to generate accuracy statistical reports by comparisons against the TIN and the DEM using surveyed ground control of higher accuracy. The lidar is adjusted accordingly to meet or exceed the vertical accuracy requirements. - The lidar tiles were reviewed using a series of proprietary QA/QC procedures to ensure it fulfills the task order requirements. A portion of this requires a manual step to ensure anomalies have been removed from the ground class. - The lidar LAS files are classified into the Default (Class 1), Ground (Class 2), Low Noise (Class 7), Water (Class 9), Ignored Ground (Class 10), Bridge Decks (Class 17) and High Noise (Class 18) classifications. - FGDC Compliant metadata was developed for the task order in .xml format for the final data products. - The horizontal datum used for Coastal delivery was referenced to Mississippi State Plane East Zone, NAD83(2011). The vertical datum used for the task order was referenced to NAVD88, GEOID12A/12B in units of US Survey Feet.
• 2017-04-01 00:00:00 - The NOAA Office for Coastal Management received the LAS files in from Mississippi DEQ. The data was received in Mississippi State Plane East (zone 2301) horizontal coordinates in US survey feet with vertical coordinates referenced to NAVD88 (Geoid12a) in feet. The Digital Coast performed the following processing for data storage and Digital Coast provisioning purposes: 1. Data were reprojected to geographic NAD83(2011) coordinates in decimal degrees. 2. The vertical coordinates were transformed to ellipsoidal heights in meters using Geoid12a.

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=5168;