Data Management Plan

The mosaic image contained in this file is comprised of multiple CASI 1500 scanlines that were collected by the Coastal Zone Mapping and Imaging Lidar (CZMIL) system along the shoreline of Alaska. CZMIL integrates a lidar sensor with topographic and bathymetric capabilities, a digital camera, and a Itres' CASI-1500 hyperspectral imager on a single remote sensing platform for use in coastal mapping and charting activities. The CASI-1500 imagery was collected at an altitude of 400m, a ground swath of 300m and at a resolution of 1m by 1m ground sample distance (GSD). Native CASI-1500 imagery data is not generally in a format accessible to most Geographic Information Systems (GIS). Specialized in-house and commercial software packages processe the imagery data into GIS-compatible products for visualization and further analysis. Horizontal positions, projected in Universal Transverse Mercator (UTM), are referenced to the North American Datum of 1983 (NAD83). Vertical positions are referenced to the NAD83 ellipsoid. Individual image strips have been rectified and mosaicked into blocks commensurate with the collection blocks. The data file naming convention is based on the year, project, area name, product type, collection block, and survey altitude. These files have been separated and delivered by JALBTCX collection blocks. An example file name is "2019_NCMP_AK_03WVN2541_HSI.tif", where 2019 is the year of data collection, NCMP is the Effort under which data were collected, AK is the area of data collection, and "HSI" is the product type. The supplementary header file is of the same name.

Process Steps:

• 2019-08-31 00:00:00 - These data were collected using Itres Research Limited's Compact Airborne Spectrographic Imager (CASI) - 1500 owned by the USACE Army Corps of Engineers Joint Airborne Lidar Bathymetry Technical Center of eXpertise (JALBTCX) and operated through contract. The CASI-1500 is a fully programmable, pushbroom hyperspectral imager. All raw data streams were transferred to the office for downloading and processing. Optech Incorporated's HydroFusion (HF) software, which is built upon Exelis Visual Information Solutions' ENVI and IDL uses Itres' proprietary software to radiometrically correct and extract navigation data from each scanline. Proprietary atmospheric algorithms convert radiance to reflectance - depending on product type delivered. Glint and ripple correction alogrithms were used on the water surface. Final mosaics are then generated using HF function calls to Itres executables. Ground elevation Digital Elevation Models (DEM) were created from CZMIL lidar data for reference for commensurately flown hyperspectral data at 400m. USGS NED elevation data were used for hyperspectral data collected at 2000m. The USGS NED data was warped using GDAL and then elevations where move from NAVD88 to NAD83 Ellipsoid using VDATUM. Each scan line was geometrically corrected with the ground elevation DEMs and mosaicked using ground lookup tables (GLU) placing pixels closest to nadir where scanlines overalp. Final mosaics were QA/QC in ENVI and ArcMAP and compared to field collected, ground spectrum samples where available. Finally metadata were generated.

These data have been developed from the best available sources. Although efforts have been made to ensure that the data are accurate and reliable, errors and variable conditions originating from physical sources used to develop the data may be reflected in the data supplied. Users must be aware of these conditions and bear responsibility for the appropriate use of the information with respect to possible errors, scale, resolution, rectification, positional accuracy, development methodology, time period, environmental and climatic conditions and other circumstances specific to these data. The user is responsible for understanding the accuracy limitations of the data provided herein. The burden for determining fitness for use lies entirely with the user. The user should refer to the accompanying metadata notes for a description of the data and data development procedures.