basics of using lidar data - esci.umn.edu · 4 “basics of using lidar data” workshop exercises...
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2 “Basics of Using LiDAR Data” Workshop Exercises
Basics of Using LiDAR Data
Workshop Exercises
Exercise 1: Raster Processing ..............................................................................................................4
A. Training Data Acquisition and Description ........................................................................................... 4
B. Basic Properties - Examining Source Data ............................................................................................ 4
C. Raster Processing .................................................................................................................................. 5
Activate Spatial Analyst Extension ........................................................................................................ 5
Spatial Analyst Tools ............................................................................................................................. 5
Raster Calculator ................................................................................................................................... 6
Raster Environments ............................................................................................................................. 6
Raster Processing – Depressions Example ............................................................................................ 7
Raster Clipping .................................................................................................................................... 12
Exercise 2: Minnesota LiDAR Data .................................................................................................... 13
A. Where and How to Get Minnesota LiDAR Data .................................................................................. 13
Install FileZilla ...................................................................................................................................... 13
Getting Minnesota LiDAR Data – Easy as 1, 2, 3 ................................................................................. 14
Minnesota LiDAR Quick Download Guide........................................................................................... 15
B. Navigating ........................................................................................................................................... 15
RTM – Read The Manual ..................................................................................................................... 15
Site Layout .......................................................................................................................................... 16
Data Folder.......................................................................................................................................... 17
Download ............................................................................................................................................ 17
C. File Formats and Data Types ............................................................................................................... 18
Geodatabase ....................................................................................................................................... 18
Raster/DEM – GRID ............................................................................................................................. 18
Feature Data – Contours, Breaklines, Bare Earth Points and Buildings .............................................. 18
Point Cloud – LAS/LAZ ......................................................................................................................... 19
Terrains ............................................................................................................................................... 19
Full Data Folder Description ............................................................................................................... 19
**NOTES – Additional Resources ............................................................................................................ 21
3 “Basics of Using LiDAR Data” Workshop Exercises
Exercise 3: Visualization and Management ....................................................................................... 22
A. Display Techniques .......................................................................................................................... 222
Default Layer Properties ..................................................................................................................... 22
Stretch Types .................................................................................................................................... 233
Statistics Calculations.......................................................................................................................... 23
Adding Color ..................................................................................................................................... 244
Adding Depth and 3D Effect ............................................................................................................. 244
B. Visualization / Comparative Techniques........................................................................................... 255
Orthophoto/DEM Comparison ......................................................................................................... 255
Add MNGEO WMS Service ................................................................................................................ 255
Swipe ................................................................................................................................................. 255
C. Managing Large Datasets .................................................................................................................. 266
Basic Tips ........................................................................................................................................... 267
Strategy - Divide, Then Conquer ..................................................................................................... 2727
Batch Processing ............................................................................................................................. 2828
4 “Basics of Using LiDAR Data” Workshop Exercises
Exercise 1: Raster Processing
A. Training Data Acquisition and Description
1. All data will be provided and work will be done on a USB thumb-drive given to you at the beginning of the workshop exercise. This thumb-drive is to be returned to the instructor before leaving the training room.
2. Load the thumb-drive, right click on start, then left-click on “explore” 3. Double click on the “basics” folder. This is where all data will come from and be saved to. 4. Start ArcMap
B. Basic Properties - Examining Source Data
1. Start ArcMap.
2. Select “add-data” , navigate to \thumb-drive\“basics” and add DEM. 3. Select this DEM Layer, right-click Properties.
o Click the Source tab in the properties for the layer to get a full description of the layer including cell size, format, extent and spatial reference.
o Now click the Symbology tab. Here you can change the color ramp. o Put a check mark on the Hillshade option to emphasize the terrain features. This does
not affect the analysis or change the data, but aids in visualization – more on that later. o Once you have examined all layer properties, click OK to close the layer properties.
4. Open ArcCatalog . Navigate to the thumb-drive. 5. Observe the different notations and icons that ArcCatalog uses between, shapefiles, Arc Grids,
etc. 6. Right click the Windows “Start” button, and select explore 7. Observe the how the folder and file structure is different for an Arc Grid than other formats.
TIP – Always use ArcCatalog to copy, move, or delete raster data. Arc Grids utilize a two folder system with one folder containing the raster geometry, and the other “info” folder containing tabular information for ALL rasters in the same directory.
5 “Basics of Using LiDAR Data” Workshop Exercises
C. Raster Processing
Activate Spatial Analyst Extension
1. From the Customize Menu, select Extensions and check-on the Spatial Analyst extension.
2. Click Close
Spatial Analyst Tools
1. Launch ArcToolbox by opening the ArcToolbox Window.
2. Expand the Spatial Analyst Tools, and observe the following
sub-categories: o Distance o Extraction o Hydrology o Interpolation o Map Algebra o Surface o Zonal
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Raster Calculator
1. Go to ArcToolbox > Spatial Analyst Tools > Map Algebra > Raster Calculator. 2. Observe interface and listen to demo:
Raster Environments
1. Go to ArcToolbox > Spatial Analyst Tools > Map Algebra > Raster
Calculator. 2. Select Environments to access environment settings. 3. Most common raster processing environment settings to manipulate
are as follows: o Processing Extent
Snap raster o Raster Analysis
Cell size
Mask o Raster Storage
Pyramid
Raster Statistics
Compression
7 “Basics of Using LiDAR Data” Workshop Exercises
Raster Processing – Depressions Example
For the below example, we’ll be utilizing our DEM to perform a simple depression identification. You
will calculate sinks in the landscape, and then use the raster calculator to isolate those sinks.
Sink Filling
1. Launch ArcToolbox by clicking the toolbar icon. 2. Click on Spatial Analyst Tools Hydrology Fill .
3. Input Surface Raster: DEM (select it from the drop-down). 4. Output Surface Raster: Browse to thumb-drive\basics and name 'fill_dem'. 5. Z limit: the maximum elevation difference between a sink and its pour point to be filled.
o Note: The default will fill all sinks regardless of depth. 6. The output surface raster is added to your map as a new layer. 7. Spend some time zooming in to different parts of the dem, checking layers on/off to see the
effect of pit-filling the DEM.
8 “Basics of Using LiDAR Data” Workshop Exercises
Isolating Depressions
1. Launch the Raster Calculator by clicking on Click on Spatial Analyst Tools Map Algebra Raster Calculator
2. Enter formula so the result looks exactly like the formula below: “dem” – “fill_dem” 3. Output Raster – thumb-drive\basics\depressions 4. Click OK to run the calculation. 5. Observe how negative values for “depressions” indicate depth of depression.
Problem – To make use of the many other raster tools available, it’s often useful to have an integer
version of the raster. Building a raster attribute table, converting the raster to a polygon, and other
functions require it. Data downloaded from the LiDAR FTP server is a single-band raster, type FLOAT.
However, if we convert to an integer grid as-is, we lose much of the precision (i.e. decimals) that LiDAR
is so renowned for.
9 “Basics of Using LiDAR Data” Workshop Exercises
Solution #1 – If your data was in meters, we could convert to feet automatically by doing the following. In this instance, we’ll convert to meters just to show you how it’s done
1. Launch the Raster Calculator by clicking on Click on Spatial Analyst Tools Map Algebra Raster Calculator
2. Enter formula so the result looks exactly like the formula below: "dem" / 0.3048 3. Output Raster – thumb-drive\basics\dem_ft 4. Click OK to run the calculation.
10 “Basics of Using LiDAR Data” Workshop Exercises
Solution #2– We’ll convert the DEM to an integer grid, but not before multiplying by a specified amount so as to preserve the decimals.
1. Launch the Raster Calculator by clicking on Click on Spatial Analyst Tools Map Algebra Raster Calculator
2. Enter formula so the result looks exactly like the formula below: "dem_ft” * 1000. Multiplying by 1000 will allow us to preserve 3 decimal places. After performing whichever functions are necessary, such as conversion to polygons, we can divide by 1000 to restore to the one-thousandths decimal place.
3. Output Raster – thumb-drive\basics\dem_ft1k 4. Click OK to run the calculation.
5. Launch the Raster Calculator by clicking on Click on Spatial Analyst Tools Map Algebra Raster Calculator
6. Enter formula so the result looks exactly like the formula below: Int("dem_ft1k"). 7. Output Raster – thumb-drive\basics\dem_int 8. Click OK to run the calculation.
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9. Alternatively, we could’ve done all of these calculations in one window by entering the following: Int(1000 * ("dem" / 0.3048))
The point of the long-hand procedure, only to reveal an “easier” way to perform the same calculation is
to drive home the point of the Raster Calculator living up to the term “Map Algebra.” Any raster can be
utilized with any mathematical and algebraic function to yield a wide array of results. Ultimately, this is
one of the key features that makes the raster processing environment so powerful.
12 “Basics of Using LiDAR Data” Workshop Exercises
Raster Clipping
Clipping out portions of raster data to work on as “pilot-areas” is a critical concept used when
determining best-practice workflows. In this instance, we want to work with both LiDAR data and a
raster that displays conservation-value on the landscape. To make for easier processing, we need to clip
this layer (EBI300) to the same extent as the DEM, and use “snap-to-raster” to ensure they have the
same spatial origin.
**NOTE – There are several ways to clip a raster in ArcGIS. This method, titled “extract by mask” is
useful because you can utilize feature data OR raster data for a clip layer (mask).
1. Select “add-data” , navigate to \thumb-drive\basics and add ebi300.
2. Go to ArcToolbox > Spatial Analyst Tools > Extraction > Extract by mask. 3. Input Raster: ebi300 4. Mask Data: dem 5. Output Raster: thumb-drive\basics\ebi_300_msk 6. Select Environments 7. Under Processing Extent, set snap raster to: DEM
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Exercise 2: Getting LiDAR Data
A. Where and How to Get Minnesota LiDAR Data
Minnesota LiDAR Data is at ftp://lidar.dnr.state.mn.us/ and
ftp.lmic.state.mn.us/pub/data/elevation/lidar/data
LMIC FTP download site is faster and preferred at this time
Interactive DNR download and viewer to come in next few months - http://arcgis.dnr.state.mn.us/gis/lidarviewer/
Large file sizes require more reliable transfer than web browser connections. Instead, use a third party FTP client. Filezilla FTP is recommended and is free.
An interactive download site is currently under development – similar to International Waters Institute LiDAR Download Site at http://gis.rrbdin.org/lidarapps.htm
Install FileZilla
http://filezilla-project.org/
1. Navigate to the thumb-drive, double click “FileZilla_3.5.3_2in32-setup.exe” in the root directory of the filesystem.
2. Custom install directions will be given during the exercise to install FileZilla on the thumb-drive itself.
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Getting Minnesota LiDAR Data – Easy as 1, 2, 3
1. Open Filezilla FTP client and enter host – lidar.dnr.state.mn.us – then click “Quickconnect”. 2. Browse the remote site for LiDAR data of interest (See Quick Download Guide below). 3. Drag and drop folder geodatabase from remote site to resident file-space of your own
choosing.
1
2 3
15 “Basics of Using LiDAR Data” Workshop Exercises
Minnesota LiDAR Quick Download Guide
B. Navigating
RTM – Read The Manual
DON’T IMMEDIATELY DOWNLOAD!
Watchmefirst.swf – Adobe Shockwave File – Video Tutorial on entire site
Readmefirst.rtf – Each folder has this written description of contents of folder
Where To Get It
What Data Type?
What Geographic
Scale?
MN GEO FTP LiDAR
Quick Download
Guide
FTP Download Site
County
DEM
Contours
lmic.state.mn.us/pub/data/elevation/lidar/data/coun
ty
Smaller
DEM
Contours
Bare Earth Points
lmic.state.mn.us/pub/data/elevation/lidar/data/co
unty
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MN GEO Site Layout - /pub/data/elevation/lidar
\county – this is the folder where all of the LiDAR and derived products are stored. \examples – examples of LiDAR products and data samples.
\lidar_sample – contains a sample of a standardized LiDAR data packet \maps – maps and other samples depicting LiDAR or derived products, usually as PDF files.
\projects – smaller geographic areas, project-specific lidar data \tile index– tile index information, graphical and .lyr file \tools – contains various tools for working with LiDAR data.
\lastools – a set of open source tools for working with LAS data files. \scripts – a variety of scripts not associated with toolboxes. \toolboxes – ArcGIS toolboxes and associated files.
\training – contains various training materials that have been contributed by the Authors.
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Data Folder
Organized by tiling scheme or geographic extent AND data type
o Geodatabase
All raw data packaged by USGS 1:24k Quarter-Quarter Quadrangle
o Elevation_data.gdb.zip
County-wide Dataset
o laz
Compressed .LAS files – RAW data only
Download
Due to the size of both the county-tiled and LAS/LAZ format data, we will not be doing exercises with
these data. Check the **NOTES section at the end of this exercise to view additional resources for
working with these datasets.
1. Open Filezilla FTP client and enter host – lidar.dnr.state.mn.us 2. Right click in your “Filename” window and under the thumb-drive\basics folder, select
“Create New Directory” 3. Name the directory “raw_data” 4. Browse the remote site pubData Elevation Lidar CountyNicollet
Geodatabase 4326-24-63.gdb 5. Left click this file, hold, then drag into recently created “raw_data” directory
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While these data download – we’ll go over some of the file formats and data types available on the LiDAR FTP server.
C. File Formats and Data Types
Geodatabase
o Storage model that most of the LiDAR data will be delivered in o elevation_data.gdb – same geodatabase name for each county – File management
implications o Folder – File management implications
Cannot move items within folder separately, must maintain complete hierarchy Many contents - different data types stored within Can store derived products within or outside-of – pros/cons to
each ESRI Proprietary Model – doesn’t transfer well to Windows
world Use ArcCatalog
Raster/DEM – GRID
o Most widely used – Arc GRID raster format o Available in 1m, 3m, and hillshaded versions, county and
quadrangle tiling schemes o Used to derive several other products – Hydrology and Terrain
Analysis Modules
Feature Data – Contours, Breaklines, Bare Earth Points and Buildings
o Contours are great aid in visualization of DEM, especially in areas of relatively low relief.
o Contour lines available as 2-foot contour interval for county and quadrangle tiling schemes.
o Hydro breaklines are edge-of-water polygons. o Building footprints available in county and quadrangle tiling
schemes (where available).
19 “Basics of Using LiDAR Data” Workshop Exercises
Point Cloud – LAS/LAZ
o Point cloud data packaged as both LAS and LAZ files. o Also provided as Bare Earth Points – easier for most ArcGIS users
– requires some prep work however. o LAZ files are compressed LAS files, 10 TIMES SMALLER! –
Download these. o CONTAIN MORE INFORMATION THAN JUST ELEVATION
Need 3rd party extension or stand-alone software to utilize.
Terrains
o Combination of all above. o TIN-based data model – multi-resolution. o Advantage - Store elevation information at an
optimized resolution. o Reside in a geodatabase with the features used to
construct them.
Full Data Folder Description
\data – folder stores mosaiced lidar data as projects or counties. For most folks this is the data that they will want to download.
\county – contains county based products that are homogenized to a standard set of products with consistent names, schemas and organization. Here you will find mosaiced DEMS (1 and 3 meter), Hydro breaklines, 2 foot contours and building outlines where available.
\[county name]\elevation_data.gdb – this folder stores the elevation.gdb geodatabases (9.3 format). Each file geodatabase contains the following file structure:
DEM01 - one meter DEM DEM03 - three meter DEM DEM03HS - Hillshade of DEM03
CONTOURS – 1 or 2 foot contours (depends on data quality) HYDRO_BREAKLINES – merged edge-of-water breaklines for entire area
BUILDINGS – Merged buildings for entire area TILE_INDEX - a tile index with a field called TILE_NAME which identifies all of the tiles. VALIDATION_POINTS - a feature class of the points used in the vertical accuracy assessment qaqc - a table summarizing all of the tiles and various attributes about them - used for QA/QC purposes.
\projects - contains specific projects that are not organized by county. Products are not consistent from project to project. You will have to read through the provided documentation to understand the parameters of the project.
Available
County
Data
20 “Basics of Using LiDAR Data” Workshop Exercises
\raw – this folder stores the raw data that was used to put together the county mosaic datasets found in \data\county. This is where you will find tiles of compressed LAS files and Geodatabase files for each of the counties.
\geodatabase – this folder stores the original tiled file geodatabases (9.3 format). Each file Geodatabase contains the following file structure:
CONTOUR_DATA – Feature database Contours – contours for tile TERRAIN_DATA – feature database
Bare_Earth_Points – Bare earth points extracted from LAS files and stored as multi-point features Hydro_breaklines – edge of water breakline polygons Buildings – feature class of building outlines generated from LAS files
DEM01 – one meter DEM \LAZ – contains compressed LAS files. These compressed files are typically 10 times smaller than the original LAS files. Please download these files if you are interested in point cloud data. PLEASE NOTE: The LAS files were compressed with a utility called LASZIP.EXE. This utility is free and part of the LASTOOLS software package. This tool is available in the LAZ folder and there is also a batch file called UNZIPLAZ.BAT that will unzip all of the LAZ files in the folder.
\tile_index – all tiled data are organized by 1/16th of a USGS 1:24,000 quadrangle. This folder contains the tile index that helps you identify where the tiles are and their names. This folder stores an ESRI File Geodatabase (9.3) called indx_q006kpy4 and this GDB has a feature class named indx_q006kpy4. The field that identifies the tile names is DNR_QQQ_ID.
Available
QQ-Quad
Data
21 “Basics of Using LiDAR Data” Workshop Exercises
**NOTES – Additional Resources
Not all tools are being demonstrated in these exercises for various reasons, but here are a few useful
ones, should the need arise. Few are free, but often there are trial versions available.
LiDAR and DEM Tools – Minnesota DNR
MN DNR has developed a full toolbox of VERY useful LiDAR tools for versions 9.x and 10, available for
download on the LiDAR download site here – ftp://lidar.dnr.state.mn.us/tools/toolboxes/
Toolbox highlights include the following:
-Batch Convert to CAD -Wetness Index -Calculate Surface Area -Converting to County Coordinates -Convert Z Units from Meters to Feet -Converting Grid Z values from meters to feet -Identify Bluffs -Converting to CAD Formats -LAS to Contours 9.3 -Raster Split -Points to X,Y,Z ASCII
LAS Data
LAS Tools - ftp://lidar.dnr.state.mn.us/tools/lastools/
LP360 Lidar Tools Extension for ArcGIS - www.qcoherent.com
MARS – From Merrick – stand-alone program
LASTOOLS – command line resources (Free)
LiDAR Handler- ArcGIS Extension by the NOAA Coastal Services Center (free)
LiDAR Analyst – ArcGIS Extension - http://www.featureanalyst.com/lidar_analyst.htm
LiDAR Explorer – ArcGIS Extension
3DLiDAR Viewer – Virtual Geomatics Free LAS viewer
22 “Basics of Using LiDAR Data” Workshop Exercises
Exercise 3: Visualization and Management
A. Display Techniques
Default Layer Properties
Stretched Display o Limits “stretch” display to 2 Standard Deviations
Statistics Drive Display – based on summary stats from entire DEM
Predefined color ramp – grayscale standard
Nearest Neighbor Resampling
Most display variables changed in Layer Properties Symbology Tab
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Stretch Types
1. Select “add-data” , navigate to root directory and add DEM. 2. Select this DEM Layer, right-click PropertiesSymbology tab. 3. Under “stretched” view the “Histograms” button. When you adjust the histogram, you see
multiple sets of vertical bars: the purple bars represent the current display values, and the gray bars represent your original values.
4. Select each of the following and zoom to examine how “stretch” type affects display, paying careful attention to the notes for each one:
o Custom or Histogram Specification – Manually defined – not recommended o Standard Deviations – Standard display o Histogram Equalize – This setting accentuates minor variations – uplands in this case –
by applying the value display equally across the entire histogram o Minimum/Maximum – This setting accentuates larger variations in relief - dendritic
drainage in this case – by visually ignoring the tails of the histogram 5. Gamma – This can be used with Standard Deviation or Min/Max stretch types. By applying a
gamma correction, you can control the overall brightness of a raster dataset, to enhance the overall contrast and interpretation of the image.
Statistics Calculations
1. Select DEM Layer, right-click PropertiesSymbology tab”stretched” sub-menu 2. Select “From Each Raster Dataset” from Statistics – then zoom to different extents
24 “Basics of Using LiDAR Data” Workshop Exercises
3. If using “From Current Display Extent” for printing, you need to save as XML. 4. Select DEM Layer, right-click PropertiesSymbology tab”stretched””Statistics”
submenus to select “Import” for your previously saved XML file.
Adding Color
1. Select DEM Layer, right-click PropertiesSymbology tab”stretched” sub-menu
2. Select various displays from “color ramp” to bring out different effects. Many elevation ramps are multi-chromatic, a few will be demonstrated in this exercise.
Adding Depth and 3D Effect
Shaded relief adds depth and perspective while simulating a lighted surface (DEM). Temporary hillshade
effects can be created within Layer Properties, but are “quick and dirty,” not yielding consistent results
compared to the below method.
1. ArcToolbox Spatial Analyst Tools Surface Hillshade 2. Input Raster: DEM 3. Output Raster: thumb-drive\basics\hillshade
4. Arrange elevation on top of hillshade in table of contents 5. Make elevation display 35 – 50% transparent. Layer Properties Display Tab Transparency
25 “Basics of Using LiDAR Data” Workshop Exercises
B. Visualization / Comparative Techniques
Orthophoto/DEM Comparison
Often, the best way to understand differences in your landscape is to view each layer in
conjunction with other layers. By paying careful attention to a specific portion of the landscape,
one can overlay orthophotography on a DEM to gain a better understanding of the area.
Add Aerial Imagery – 3 ways
1. Use ArcGIS Basemap – o Pros – Fresh data, updated regularly, can be extremely high resolution especially near
urban areas o Cons – Slow, various unassociated reference layers appearing with it
2. Use downloaded imagery o Pros – Download once for your area and you have it, o Cons – Confusing website, difficult to determine which area on reference map you’re in,
have to store locally 3. Add MNGEO WMS Service
1. Open ArcMap and click on 'Add Data' 2. Look in the Catalog, and click on 'GIS Servers' 3. Highlight 'Add WMS Server' so that it appears in the Name window, and hit 'Add'. An 'Add
WMS Server' window will pop up. 4. To bring up the Imagery server, type http://geoint.lmic.state.mn.us/cgi-bin/wms? in the
URL window. You can click on the 'Layers' button to see a list of the layers available under the wms. Click 'OK'.
5. To bring up the Scanned DRG server, type http://geoint.lmic.state.mn.us/cgi-bin/wmsz? in the URL window. You can hit the 'Get Layers' button to see a list of the layers available under the wms. Click 'OK'.
6. Now when you look under 'GIS Servers' you have two new entries: 'LMIC WMS server (aerial photography) on geoint.lmic.state.mn.us' and 'LMIC WMS server (quad sheet drgs) on geoint.lmic.state.mn.us'
7. Still in the 'Add Data' window under 'GIS Servers', highlight one of the services listed under #6 to bring it into the 'Name' window, then click on 'Add'. The service, with all of its layers, has now been added to your ArcMap project.
8. Click on the '+' to open the map service
Swipe
1. To display the Effects Toolbar, right-click anywhere in the toolbar and select Effects. 2. Select the Swipe Tool to "wipe" a layer using a horizontal or vertical line across the screen.
26 “Basics of Using LiDAR Data” Workshop Exercises
3. Make sure the layer you want to "swipe" is shown in the "Layer:" box. 4. Click on the map and drag to swipe (do not release mouse button; the mouse must be depressed
to get the swipe effect.)
Example of swipe:
C. Managing Large Datasets
Basic Tips
o Gear up – Ease of use is often hardware dependent o CPU – multiple core, fast processors o RAM – 64 bit systems allow more RAM – upgrade o Disks – High speed, large – cheap!
o Work locally – network speed, USB cables, etc. slow down processing o Allow 20% overage for storage space – ensures better disk functionality, along with the option
to defrag or disk check for bad sectors o Store source elevation information only if space is available – download is fast and easy o Avoid display of multiple LiDAR scenes – hang-ups
27 “Basics of Using LiDAR Data” Workshop Exercises
o Image Analysis – Accelerated rendering, test this with larger display datasets o Calculate BOTH Statistics AND Pyramids for faster drawing later o Backup – external hard drives cheap, failing to archive data it took days to process is not o Contour data can clutter screen, set appropriate scale range limiters such as 1:10,000
Strategy - Divide, Then Conquer
A critical concept in working with LiDAR data involves
using “pilot areas” to test processing techniques and
methodology on before applying to entire dataset. The
“try it and see” approach to LiDAR processing is
frustrating and time consuming. Once processing steps
have been tested on smaller areas, utilize batch
processing or scripting to maximize “autopilot” overnight
processing.
28 “Basics of Using LiDAR Data” Workshop Exercises
Batch Processing
o Great tactic for processing any dataset which requires running the same tool against a large number of areas
o With LiDAR data, the limitation is often the processing speed in which a single dataset can be run
o Processing in these smaller chunks is more efficient should files be missing, corrupt, or otherwise unstable
o Batch processing is VERY user-friendly and non-intimidating for those who don’t write code
Document version: March 2013