2007 US Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP) Great Lakes Topo/Bathy LiDAR: Lake Erie (PA shoreline) and Lake Michigan (Manitou Islands, Grand Traverse Bay, Little Traverse Bay)

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This kmz file shows the general extent of the 2007 USACE Lake Michigan and Lake Erie topobathy

lidar data.

Date that the source FGDC record was last modified.

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Partial upload of Positional Accuracy fields only.

Partial upload to move data access links to Distribution Info.

These data were collected using the CHARTS surveys system. It is owned by the Naval Oceanographic Office and operated

through contract. The system collects topographic lidar data at 20 kHz and hydrographic data at 3 kHz. The system also

collects RGB imagery at 1 Hz. A CASI-1500 hyperspectral line scanner is integrated with the system as well. Aircraft

position, velocity and acceleration information are collected through a combination of Novatel and POS A/V equipment.

Raw data are collected and transferred to the office for downloading and processing in SHOALS GCS software. GPS data

are processed using POSPac software and the results are combined with the lidar data to produce 3-D positions for each

lidar shot. These data are edited using Fledermaus software where anomalous data are removed from the dataset.

The data are broken into files, with each covering approximately 5 km along the shoreline. The edited data are written

to 5 km tiles along the shoreline using chartsLAS, a program written by NAVO. This program reads data from the original

binary format files and produces separate ASCII files for first and last return data. The data are converted from ellipsoid

to orthometric heights, based on the GEOID03 model, within the chartsLAS program. The bathymetry files contain all of the

returns from the bathymetric sensor which include returns both above and below the water.

The NOAA Office for Coastal Management (OCM) received topo and hydro files in ASCII format. The files

contained Lidar elevation and intensity measurements. Both the topo and hydro points were classed as 'never classified.'

The data were provided in Geographic coordinates and ellipsoidal heights and in IGLD85 heights. OCM performed the following

processing to the ellipsoidal height data for data storage and Digital Coast provisioning purposes:

1. LASEdit was used to convert the ascii formatted files to las format.

2. Both the topo and the hydro points were classified as never classified. Hydro points were changed to class 11 (bathymetry)

and topo points were classified to class 2 (ground or bare earth).

3. The LAS data were sorted by latitude and the headers were updated.

The Grand Traverse Bay and Little Traverse Bay data were received by the NOAA OCM at a later date from the previoulsy processed

data (Lake Erie - PA Shoreline and Lake Michigan - Manitou Islands) in this data set. These later received data were processed

from the TL (last return topography) and H (bathymetry) ASCII files. The data were converted to las format using lastools.

The H files were converted from IGLD85 vertical datum to NAVD88 using Vdatum and then converted to ellipsoid heights using

GEOID03. Points were re-classified from 0 (never classified) to 11 (NOAA OCM bathymetry). These data were processed by NOAA OCM on 201206.