1. DISTRIBUTION OF LIDAR DATA VIA THE INTERNET Michael Hearne and Andrew Meredith Technology Planning and Management Corporation Coastal Remote Sensing Program NOAA Coastal Services Center Charleston, SC Abstract There are a large number of remotely sensed data sets in the public domain, but few of them are readily available or usable by the coastal resource management community. One of the goals of the NOAA Coastal Services Center is to take these data, remove the burden of data processing from the user, and create a more useful end product. LIDAR (LIght Detection and Ranging) is a technology that creates a promising, but difficult to use, data set. The Center has a vast quantity of high- resolution topographic LIDAR data for many of the beaches within the 48 contiguous U.S. states. To distribute this data to as many people with differing technological capabilities as possible, we developed the LIDAR DAta Retrieval Tool (LDART). LDART utilizes various web technologies that allow users to select data from specific areas and to define the final output product. The user can specify geographic projections, datums, and file formats. By providing this LIDAR data via the Internet, the Center aims to help coastal resource managers make environmentally sound, scientifically defensible policy decisions. What Is LIDAR? A remote sensing technology used to collect topographic data. Data collected via a partnership with NASA and the USGS, using an instrument called the Airborne Topographic Mapper. Data with a vertical accuracy of + 20 centimeters. What Is LDART? World Wide Web based LIDAR data selection tool created for: extracting data for a specific geographic area defining a high-resolution digital elevation data set Why Was It Created? A LIDAR data set of appreciable size contains hundreds of thousands of individual elevation measurements e.g., 320,000 individual measurements over a one-kilometer beach section. LDART was developed to remove the burden of data processing from the coastal manager,allowing them to: create a more usable data product than the raw x,y,z points easily incorporate this remote sensing data into a GIS create small, manageable data sets in a particular region of interest How Can I Define My LIDAR Data Set? The LDART User Interface allows user to define various options (Table 1): Select geographic boundaries Select state and period of interest Select survey date(s) Conclusions Topographic LIDAR data is being used for determining regulatory setback lines, and for identifying habitat for endangered beach plants. It has also been used to quantify sand volume changes on beaches in North Carolina, assess impacts from El Niño on the U.S. West Coast, and investigate variations in shoreline response to different storm events. Anyone interested in working with a high- resolution digital elevation model in coastal regions should investigate this data source. LDART can deliver GIS-ready remotely sensed data to anyone with a browser and a reasonably fast connection to the Internet, and the addition of GeoTiff as an output format allows those who are not as knowledgeable about GIS or remote sensing see the types of information that LIDAR can provide. LDART can be found at the following web address: http://www.csc.noaa.gov/ldart Step 1: Enter user information Step 2: Define spatial bounds and survey dates Step 3: Select product options Where Was Data Collected? Since the Fall of 1996, the Center in partnership with NASA and USGS has surveyed over 6100 kilometers of U.S. coastline. Table 2 shows the breakdown of LIDAR data collection by region and year. What Can I Do with the Data? All of the above images are shaded relief maps of LIDAR, created using ArcView® Spatial Analyst. In each case, blue represents lower elevations, while red represents high. From the left: Pillar Point, south of San Francisco, CA. Getting the Data Examples of binning methods Example of x,y,z point data Table 1. LDART parameters and options. Table 2. LIDAR survey coverage