Welcome to this page of links intended to aid anyone interested in using LIDAR and related technologies to create or improve orienteering maps. Feel free to email suggestions anytime to me at greg_lennon @ usorienteer dot or g.

The sections on this page are to help you get quickly to the questions you might have about using LIDAR. The links certainly overlap between categories, though, so feel free to browse the whole page too.

• What's LIDAR All About? [LIDAR Primers]

• Where are the LIDAR Pretty Pictures? [Examples of LIDAR with other photos and datatypes]

• Surely there are Powerpoint Presentations Too! [including LIDAR examples]

• But Where Can I Get Free LIDAR Data Today? [U.S. LIDAR Data Sources]

• It Doesn't Compute - or Does It? [Software - Packages, Algorithms, and the Like]

• OK, I'm Ready To Read Some Actual Articles [Selected Articles]

• Who Else Cares About This? [Group Resources]

• NOAA's LIDAR Primer One of the best short but colorful and data-packed primers around, even including a relevant FAQ section, by a government agency that has led the way in making LIDAR data understandable and accessible.

• Principles of Laser Altimeter Terrain Mapping Don't let the title scare you; this is a short (2 page) article from 2000 written by a NASA/Goddard scientist.

• A Lidar Primer This article, published in 2002 in the magazine Geospatial Solutions, presents an overview of using LIDAR technology including all steps from pre-flight planning to post-flight data management. The author was a managing director at one of the largest LIDAR services company.

• LIDAR Mapping Technology at SBG, Inc. The small private firm of Spencer B. Gross has this short but good summary of how LIDAR works followed by information on how they process the data to produce maps for their clients.

• One Simple JPEG illustrating primarily LIDAR collection but mentioning cost estimates

• O/NA LIDAR article in which I've tried to capture most of the basic of applying LIDAR to creating orienteering basemaps.

• Bainbridge Island Aerials & LIDAR plus USGS & LIDAR- comparison of oblique aerial photo, 10m DEM from traditional contours vs DEMs from LIDAR data; note fine details in LIDAR

  ---

• Thomas Hohl's IOM 2005 Presentation - definitely the best presentation out there in terms of visual impact and examples, and completely oriented towards using LIDAR for orienteering. It takes a while to download but it's worth it. Thanks Thomas!

• LIDAR Technology Overview by Amar Nayegandhi. An (June 2007) overview of both LiDAR collection and processing.

• Seeing through the trees: LIDAR for the Puget Lowland - short presentation from 2001 focusing on why LIDAR is used, and the extensive surveying done in the greater Seattle WA area

• LiDAR 101 Video Yes, a video with plenty of moving images to help explain things more clearly. Note/warning: large file (~80Mb), so it takes a while to download.

  ---

• NOAA's LDART Page This is the most straightforward place to find LIDAR data readily available for downloading, but in keeping with NOAA's mission, the focus is heavily on data from states that have at least some coastline. Scroll down a bit on this page to see list of states represented.

• Puget Sound LIDAR Consortium Folks interested in Western Washington state can get LIDAR data here from this productive consortium

• North Carolina Floodplain Mapping Program Quite a bit of data from many parts of North Carolina are available through this site

• Louisiana Data Over half of the state of Louisiana now has some LIDAR coverage; look for the LIDAR download section at the very lower left of this page of the many topographic datatypes available for downloading from the Louisiana GIS Atlas

• Idaho Data This area is west of Boise, Idaho

• NOAA's State Projects Page Select states of interest in the "Projects in My State" pull-down menu to ferret out clues about which state agencies *might* have data that they *might* be willing to share with you

• USGS Seamless Data Distribution Service This is increasingly the main (federal) repository for LiDAR info, but using the application takes patience.

• QuikGrid - This is a free Windows program that can quickly turn millions of x,y,z points into a grid and contour plot. DXF file export is supported (for import into OCAD or other programs). This program can handle more data than Surfer or Global Mapper, and per datapoint, is faster anyway at what it does. You can also get a view of the data density by overlaying the points themselves on the contours made from them.

• Surfer 8.0 - Decent all around Windows/PC program that just about does it all (including generating contours and grid math) without being Ferrari priced. [It's priced around $600.] Widely used for these reasons. Digital Grove's page does a fine job of describing Surfer's features, perhaps even better than the makers.

• Global Mapper - Geared to mapping, including built-in support to download certain topos (USGS) and aerial photos overlayed immediately on (or under) your LIDAR data. Can also generate contours, has DXF export, and many data interconversion utilities. Windows; demo program available free (no exporting/printing), full program $300.

• IDL Very widely used in the scientific community for data analysis and visualization; PC, Mac and Unix platform support, all sorts of modules.

• QT Modeler - Among the best Windows/PC programs designed for very fast visualization of large datasets like LIDAR data. Easy to use, powerful, numerous built-in algorithms. Unfortunately rather expensive, but can download a 30 day free trial. They also have a free viewer product (QT Reader) that can be used to look at some data models (like GeoTiff DEMs) but it can't import raw data or generate contours from such.

• NOAA's LIDAR Data Handler For those of you able to use ESRI software, this is the place to get NOAA's ArcView and ArcMap extensions for handling NOAA LIDAR data

• TEC's Software List - The US Army's Topographic Engineering Center has an impressively long list of "terrain visualization software" programs. Note some links are (not surprisingly, given the breadth) out of date.

• Recent U.S. Geological Survey Applications of Lidar - Overview of many ways in which the USGS is (or hopes to be) using, and distributing, LIDAR data. Worth knowing about. Quieja VR et al, Photo Eng & Rem Sens, Jan 2005

• LIDAR Product Definitions - This summary from 2002 presents the most straightforward classification of LIDAR data, starting with Level 1 (all raw LIDAR datapoints) up to Level 5 (very refined, highly classified LIDAR data including use of other datatypes like aerial info)

• Swiss QC Procedures for Lidar Data Switzerland has undertaken a country-wide survey by LIDAR, and this article discusses some of the QC procedures the government project office swisstopo has instituted to examine the LIDAR data produced by the LIDAR subcontractors

• Comparison of Filtering Algorithms What's the basis for deciding if a given LIDAR datapoint is deemed on the ground or not? This paper discusses and grades the approaches taken by 8 different algorithms

• Article on virtual deforestation (LIDAR post-processing) - classic short article from 2001 including excellent figures discussing an algorithm for filtering out the "non-ground" data (like all those trees) in order to derive a bare-earth model, from which contours can be derived.

• O-Map Yahoo! Discussion Group The largest discussion group discussing many issues relating to producing orienteering maps, including use of LIDAR (I predict)

• Red Arrow Maps - Warning: Shameless Plug - My company, which makes maps from LiDAR info, primarily to use in adventure racing and orienteering, but also for plenty of other purposes

• LIDAR Industry Directory available if you register

• American Society for Photogrammetry and Remote Sensing Spearheading standards as well as serious study of the issues; international counterpart is the ISPRS

• Academics - and here's the largest list I've ever seen of links to all things GIS/aerial/etc, maintained by Geography Prof Gordon Petrie

• FEMA LIDAR Guidance - this Appendix is the standard for LIDAR-oriented contractors working with the government, and can be studied both to learn about LIDAR and to help craft (private) contracts with a vendor. Related issues include data standard specifications, which are in another FEMA publication.

I welcome your comments. Please alert me to anything I may have overlooked.