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UNDERSTANDING LIDAR LIGHT DETECTION AND RANGING LIDAR is a remote sensing technique that can measure the distance to objects on and above the ground surface.

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Presentation on theme: "UNDERSTANDING LIDAR LIGHT DETECTION AND RANGING LIDAR is a remote sensing technique that can measure the distance to objects on and above the ground surface."— Presentation transcript:

1 UNDERSTANDING LIDAR LIGHT DETECTION AND RANGING LIDAR is a remote sensing technique that can measure the distance to objects on and above the ground surface by illuminating the targets with a laser light and analyzing the backscattered light. LIDAR produces High accurate x,y,z measurements

2 TYPES OF LIDAR Airborne Airplanes and helicopters are used to acquire data over broad areas. The majority of these platforms cover about 50 kilometers per hour with a high accuracy level. Airborne LIDAR systems are the most commonly used for generating DEM (Digital Elevation Models). Ground based Offers a street perspective and can be mounted in cars, boats, trucks, tripods or trains. Is great for smaller areas where higher density is required.

3 IMPORTANT THINGS TO KNOW ABOUT LIDAR Point spacing of your LIDAR Data Refers to how close the laser points are to each other. This is important because the point spacing determines the resolution of derived products. If you want to create building footprints you need at least 1 meter spacing. Type of files supply with your LIDAR LAS files or ASCII Intensity images Raster files (DEM) Metadata QA and QC of your data Completeness of data (LAS files, intensity images, etc) Comparison of elevations among different deliverables Classification of your data. How many classes does your LAS point data contain? Every point of your LIDAR has a classification assigned to it that defines the type of object and its correspondent reflected laser pulse. These classifications are defined using numeric integer codes.

4 IMPORTANT THINGS TO KNOW ABOUT LIDAR The SC Consortium Project uses the following classification: The ESRI LAS 1.1 standard use this classification:

5 IMPORTANT THINGS TO KNOW ABOUT LIDAR Understanding Returns The laser pulse emitted from a LIDAR system reflects from objects on and above the ground surface. A laser pulse can return to the LIDAR system as one or many returns. The first return includes the buildings, tree canopy and is referred to a DSM (Digital Surface Model). The last return or bare earth surface contains only the topography and is called a DEM (Digital Elevation Model).

6 SOFTWARE YOU NEED TO INTERACT WITH LIDAR The Data derivatives and analysis you can perform from LIDAR mainly depends on the software and type of data you have. Stand-alone applications Quick Terrain Modeler (Applied Imagery) MARS Explorer/Explorer Pro (Merrick) LAS Tools (free) http://www.cs.unc.edu/~isenburg/lastools/http://www.cs.unc.edu/~isenburg/lastools/ ArcGIS extensions LIDAR Analyst (Visual Learning Systems) LP360 (QCoherent) 3D Analyst

7 SOFTWARE YOU NEED TO INTERACT WITH LIDAR ArcGIS 10.1 Supports the following datasets: Terrain dataset 9.2 Mosaic datasets 10 LAS datasets 10.1

8 SOFTWARE YOU NEED TO INTERACT WITH LIDAR ArcGIS 10.1

9 ARC GIS 10.1 PROFILE VIEW EDITING 3D WINDOW ARC GIS 10.1 ARCSCENE 10.1 SOFTWARE YOU NEED TO INTERACT WITH LIDAR

10 LIDAR APPLICATIONS & USES Contour Maps Land Slip Risk Assessment Bathymetric Biomass Study Mining Corridor and Quarrying Flood Analysis Hydrology Seismic Hazards Pipeline Surveys Highways Railways Infrastructure Design Environmental Planning Engineering Planning Telecommunications City Models Electricity and Transmission lines CONTOURS HYDROLOGY DESIGN PLANNING

11 LIDAR APPLICATIONS & USES DEM DSM CITY MODELS RASTERS3D VIEWS

12 LIDAR TRAINING ACCESING LIDAR SC DNR http://www.dnr.sc.gov/GIS/lidarcounty.htmlhttp://www.dnr.sc.gov/GIS/lidarcounty.html NOAA http://www.csc.noaa.gov/digitalcoast/data/coastallidar/index.htmlhttp://www.csc.noaa.gov/digitalcoast/data/coastallidar/index.html USGS http://lidar.cr.usgs.gov/http://lidar.cr.usgs.gov/ OPEN TOPOGRAPHY http://opentopo.sdsc.edu/gridsphere/gridsphere?cid=datasetshttp://opentopo.sdsc.edu/gridsphere/gridsphere?cid=datasets NOAA http://www.csc.noaa.gov/digitalcoast/training/intro-lidarhttp://www.csc.noaa.gov/digitalcoast/training/intro-lidar ESRI

13 CONCLUSION In conclusion, processing large amounts of LIDAR points can be time consuming, no matter what method or software you use. It is important to take into account considerations such as: point density of your LIDAR points, desired resolution of rasters, and extent of project. Analyzing these considerations will help you come up with a plan to process LIDAR data.


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