Data Management Plan

NOAA Office for Coastal Management received the 2001 Lake Ontario dataset with 2 separate metadata records in 2013 on a hard-drive device from the USGS Center for LiDAR Information Coordination and Knowledge (CLICK); the first record was for the topographic portion of the shoreline from the USACE Detroit Office collected in May of 2001 and a second stating the USACE JALBTCX SHOALS system as having collected the bathymetric points for these same areas in August of 2001. The collection dates and GPS times correspond to each having successfully collected and delivered their respective areas. This record is a combination of the two and will highlight sections from both in order to create a complete and complementary metadata record. The original metadata records will be available by request only.

This data set is the raw topographic LIDAR data set. The data set contains selected base categories of geographic features, and characteristics of these features (X,Y,Z), in digital form. The X,Y represent geographic coordinates and the Z represents elevation in meters. The information was collected by EarthData International, LLC for the U.S. Army Corps of Engineers, Detroit District. This collection was done on the behalf of the Lake Ontario St. Lawrence River Study by the International Joint Commission.

These data were collected by the SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) system which consists of an airborne laser transmitter/receiver capable of measuring 400 soundings per second. The system operates from a deHavilland DHC-6 Twin Otter flying at altitudes between 200 and 400 meters with a ground speed of about 100 knots. The SHOALS system also includes a ground-based data processing system for calculating accurate horizontal position and water depth. Lidar is an acronym for LIght Detection And Ranging. The system operates by emitting a pulse of light that travels from an airborne platform to the water surface where a small portion of the laser energy is backscattered to the airborne receiver. The remaining energy at the water's surface propagates through the water column and reflects off the sea bottom and back to the airborne detector. The time difference between the surface return and the bottom return corresponds to water depth. The maximum depth the system is able to sense is related to the complex interaction of radiance of bottom material, incident sun angle and intensity, and the type and quantity of organics or sediments in the water column. As a rule-of-thumb, the SHOALS system should be capable of sensing bottom to depths equal to two or three times the Secchi depth.

Process Steps:

• 2001-05-09 00:00:00 - The aircraft was based at Genessee County airport located in Batavia, New York. During the first airborne mission on May 09 Area #1 was completeley collected. For the duration of the data collection there were 2 stationary GPS receivers in constant operation. One receiver was located at the Genessee county airport. The second GPS receiver was operated by Costage Engineering located in Rochester, New York. Both instruments collected GPS phase data at 1 Hz. for the duration of the mission.
• 2001-05-10 00:00:00 - A second flight was executed on May 10, 2001. During this airborne mission Area #2 and Area #3 were completely collected. During the data collection there were 3 stationary GPS receivers in constant operation. One receiver was located at the Oswego County Airport, NY. A second receiver was located at the Williamson-Sodus Airport. The third receiver was located at the Genessee County airport. All 3 instruments collected GPS phase data at 1 Hz. for the duration of the mission.
• 2001-05-09 00:00:00 - LIDAR data was collected at a flying height of 8,000't AMT (above mean terrain), at an average post-spacing of 4 m, at a laser pulse rate of 15 kHz, and with a field-of-view (FOV) of 40 degrees. The average swath width of the LIDAR flight lines was 5800'. Survey data also was collected over the project area to check the vertical accuracy of the LIDAR dataset.
• 2001-08-01 00:00:00 - The SHOALS airborne system acquires a tremendous volume of raw data during a single mission. The lidar data are unique and require a specialized Data Processing System (DPS) for post-processing. The DPS main funcions 1) import airborne data stored on high density data tape; 2) perform quality control checks on initial depths and horizontal positions; 3) provide display and edit capabilities; 4) calculate depth and position (XYZ) values for each sounding; and 5) output final positions and depths for each sounding.
• 2006-07-07 00:00:00 - Original reach-specific topographic LIDAR data were merged, checked for consistency, and packaged/compressed using the gzip compression utility.
• 2006-07-10 00:00:00 - Original reach-specific bathymetric LIDAR data were merged, checked for consistency, and packaged/compressed using the gzip compression utility.
• 2015-07-01 00:00:00 - The NOAA Office for Coastal Management (OCM) received ASCII text files without classifications or complete attributes for each point. The data were received in UTM Zone 18 (meters) and referenced vertically to NAVD88 (meters) using the Geoid99 model in meters. Three separate areas arrived in OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. ASCII files were converted from to LAS files with LASTools (txt2las). 2. LAS files were removed of any duplicated points and extraneous points were reclassified to noise. 3. The LAS tiles were then processed to reclassify unclassified topographic points to ground using an existing shoreline footprint from NOAA. 4. The LAS tiles were then processed to reclassify unclassified to bathymetric points for all submerged, open water area points. Processing errors were caused by data uncertainties beyond the reasonable extent of bathymetric depths (for 2001) therefore these points were not reclassified to bathymetric points, class 11. 5. The LAS files were transformed to geographic (decimal degrees), ellipsoidal coordinates (meters) referenced to the Geoid12a model.

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4700;