Don, That's interesting. I believe that Hans Andersen may have been involved with the development of UWash's FUSION publicly available free software or at least works with it's creators. Fusion, according to the USFS referenced tutorials, allows users to develop tree height data from LiDAR data and visualizations with georeferenced DOQQ's (digital ortho quarter-quads) by processing data with a combination of a Windows GUI and DOS command line tools.
http://forsys.cfr.washington.edu/fusion.html http://www.fs.fed.us/eng/rsac/fusion/ There is no LiDAR data available for Wisconsin, but I've been playing with the data for North Carolina, which has both 1998 CIR DOQQ's and recent Lidar data with tiles based upon DOQQ's. I hope to try to find J.Kelly's upper Wright Creek big trees (from a recent post here) on the Santeelee Creek DOQQ and LiDAR data to try to prove it out for usefulness to ENTS. Hopefully, I'll have local data to play with some time soon. Wisconsin's county governements are starting to acquire LiDAR data but aren't making it public domain - instead, selling it for thousands of dollars per user license! If I am successful with the process, I'll post the steps here later. Paul ---- DON BERTOLETTE <[email protected]> wrote: ============= Paul- I'm sure I'm oversimplifying it, but LIDAR has two wave types, one P and one L. P penetrates the forest canopy and L is 'slowed' by the crowns. The difference is the tree heights. So just using the P wave, one could create a LIDAR equivalent of a DEM (Digital Elevation Model-a 3D base map). With High Density L waves, there are 4 pie-plate sized "hits" per square meter, with Low Density L waves, you only get 1 "hit" per square meter, but is much cheaper. You mentioned U. of Washington folks, one of the two people I'll be joining, perhaps next month for a trip out into the field, is one of them...Hans Andersen is often one of three folks that co-author many LIDAR papers (for example, Andersen, H.-E., S.E. Reutebuch, and R.J. McGaughey. 2006, Forest measurement and monitoring using high-resolution airborne LIDAR. Society of American Foresters (SAF) South Puget Sound Chapter meeting, March 16, 2006, Fife, WA) Back when I using FARSITE to model fire area growth, one of the hardest inputs to get was crown bulk density...what better way then to use LIDAR to obtain that! I think it would be an exciting time for young folks with the 'knack' to be in this field. >From my initial understanding (and I'm just getting my feet wet in LIDAR), one >can do pretty well with a moderately competent home computer, as long as the >datasets are relatively small. LIDAR is very data-rich, so large area >investigations would move you into the workstation arena pretty quick. -Don From: [email protected] To: [email protected] Subject: [ENTS] Re: Lidar data availability and possible application Date: Thu, 19 Feb 2009 08:05:15 -0600 Don, I've been following LIDAR for a long time and waiting for it's practical application by the general public. The time is close to arriving with fast home computers, downloadable datasets, and amazingly, some free, public domain processing and visualization software. Once all the pieces can be put together into a reasonable process, then we take advantage of this technology. I've been following LIDAR since I first learned that it was being used to measure topography, tree height, leaf area indices,etc. probably years ago. I found the information that I sent yesterday while researching old USGS aerial photos. On the USGS EarthExplorer web site, you can search for all possible downloadable or orderable USGS data on a specific point on the earth based upon graphic map selection or coordinate entry. I was looking at their USGS and Army Map Service archive which goes back to 1939? for aerial photography. They have georeferenced photo mosaic indices that can be browsed to get medium resolution downloadable roll and frame numbers to browse and download for old frames that aren't searchable yet. I was browsing the more recent NAPP imagery and the older NAPP and Army mosaics, then browsed the preview thumbnails and low res imagery, then downloaded medium res frame scans. While "poking" around on the USGS web site imagery product page, http://www.usgs.gov/pubprod/aerial.html, I noticed that they had a special link for LIDAR data that I have not seen before, so I investigated... Anyway, I thought that some topographic data was inherent in raw LIDAR data. Forested areas can be post-processed to "remove" the trees from data to produce "bare earth" topographic data without using secondary sources that aren't as accurate or at least relative to the local tree height and density data. The raw data can also be used to produce LAI data, so it is obviously giving much more data than just the height to the first hard object. I believe that this was inferred by articles posted here earlier about LIDAR tracking of invasive tree species in Hawaii? and for locating potential ivory-billed woodpecker habitat. You guys might want to talk to BVP about it at Congaree. I believe that his University is one with a remote sensing lab that is actively involved with LIDAR and natural resources/forestry applications. Non-Lidar FYI: Additionally, recent high (2005 & 2008) and med. res. (2004&2006) leaf-on National Ag. imagery is available at http://datagateway.nrcs.usda.gov/ or from local sites of members of the USGS AmericaView.org program, such as http://www.wisconsinview.org/ Regards, Paul J. ----- Original Message ----- From: DON BERTOLETTE To: [email protected] Sent: Thursday, February 19, 2009 2:00 AM Subject: [ENTS] Re: Lidar data availability and possible application Ed- It might be that the NPS dataset could be accessed by an ENTS volunteer willing to spend time at the NPS office that has Congaree LIDAR imagery. Often times they'll have competent computer facilities. Gary Beluzo has a potential solution, with GIS computer competency. I guess my point is, maybe not all ducks are yet in a row, but enough of them are that it may be worth looking into. Your comment re topo surface elevation data being subtracted from the LIDAR data is correct...it's simple mathematics at one level, but with enormous repetitions such as computers are uniquely suited for. The bottom line? If we can access ACCURATE tall tree location data in the Congaree, it can be later used as an axillary data layer, and co-registered to LIDAR. It may be that ground truthed data as accurate as ENTS collects might be valuable to NPS folks...something could be worked out, perhaps? GPSs like Will's new Garmin are capable of being averaged, downloaded and post-processed into a potentially valuable dataset. -Don From: [email protected] To: [email protected] Subject: [ENTS] Re: Lidar data availability and possible application Date: Thu, 19 Feb 2009 01:49:01 -0500 Don, Paul, I certainly can see the applications of the LIDAR data to the work ENTS people are doing. For example if you had the topographic surface elevation data for a site and the LIDAR showed the top of the trees, then it would be feasible with the right software to simply subtract the two and get a tope of canopy height. One of the things we are all aware of is that trees in valleys tend to be taller than their counterparts on the hilltops resulting in the surface of the tree tops reflecting a more subdued version of the general topography of the surface. Dale has observed that along these river corridors the trees near the base of the slope at the side of the valley wall tend to be taller than those more in the flood play and on the slopes above. These relationships that can be observed would stand out in a topo of canopy height generated by this process and the validity of these assumptions could be determined and documented. Certainly it would give a broader overview things like canopy height topography relationships, and canopy height and relationships to many different environmental parameters. What relationships are there that might jump out at you once the data is manipulated, compiled, and displayed? It is something worth pursuing, but for me at the moment I doubt I have the capacity to manage these data sets effectively on my laptop, and even if I could I don't have the programs needed to do so, and don't have the topographic and LIDAR datasets If big chunks of the LIDAR is available online, that is great, but I still would need the topo data sets that would be compatible with the process, and the data manipulation programs. I don't have the bucks for a good GIS package or even a minimal one. (If you have sources of freebies let me know.) I think many ENTS are interested in the LIDAR data, but just don't have the ability to make use of the data without being at a university. Ed ----- Original Message ----- From: DON BERTOLETTE To: [email protected] Sent: Thursday, February 19, 2009 1:15 AM Subject: [ENTS] Re: Lidar data availability and possible application Paul- You and I may be the only ones interested...I posted several weeks back when I read Allen's post on the LIDAR that NPS and another agency had, of the Congaree. Of course when I heard that there was already imagery for the Congaree, I thought, what do we need to collect to be able to connect with it. Accurate GPS locations. That's all. So I'm hoping that the Congaree folks have "synched" their GPS's! At least have them all on the same Datum/Projection. My interest has taken me to the Web, where I've found public domain software called FUSION, that works with the LIDAR data. You can accurately measure tree heights to .5 to 2 feet, depending on data density. I'm going out next month with some Inventory folks, who will visiting a site in advance of their upcoming Forest Inventory, which will involve LIDAR. High density LIDAR data can collect up to 4 "hits" per square meter...pretty data rich remote sensing! One of the guys that I'll be meeting with co-wrote the FUSION software, and is pretty up on this stuff. How was your interest piqued? -Don From: [email protected] To: [email protected] Subject: [ENTS] Lidar data availability and possible application Date: Wed, 18 Feb 2009 23:27:05 -0600 Will, There was some mention of LIDAR applications in the past here. The USGS has a LIDAR web site: http://lidar.cr.usgs.gov/ which includes a data viewer for finding publicly available LIDAR data: http://lidar.cr.usgs.gov/LIDAR_Viewer/ There is a lot of spotty coverage of the U.S., but it looks like all of North Carolina is covered with free data downloads based upon tiles georeferenced to to 24K USGS topographic quadrangle map names and 4 data file tiles per quad. I'm not sure how useful it is depending upon the resolution that is supplied. Someone has written software to allow LIDAR data to be converted to be used in Google Earth for viewing. http://www.cs.unc.edu/~isenburg/ I'm not sure if he is converting it to bare earth topography or using canopy heights for the surface data. . There is also a cool looking downloadable LIDAR viewer/visualization tool at: http://lidar.asu.edu/LViz.html However, it looks like it might not work with the native data format of the LIDAR data. Some work needs to be done to figure this all out. For others elsewhere in the U.S., I have found that some state universities have remote sensing departments that provide additional data. For instance, the USGS has about 1/3 of Louisiana covered with freely available LIDAR data, but LSU's LIDAR page on the Links section of the first USGS page above has most of the state covered. Paul J Get more out of the Web. Learn 10 hidden secrets of Windows Live. Learn Now<BR See how Windows Mobile brings your life together—at home, work, or on the go. See Now<BR _________________________________________________________________ See how Windows connects the people, information, and fun that are part of your life. http://clk.atdmt.com/MRT/go/msnnkwxp1020093175mrt/direct/01/ --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
