Wendy,

There are different degrees of LiDAR remote sensing. Large scale (10m-30m) resolution can be used to find large sites and old road. However, 2m resolution or better is preferable. When possible I process LiDAR at one-third meter in order to look for archaeological sites or features on sites. Attached is a Civil War battery found through LiDAR.

JAG

I just read an article about a new Viking site found in Newfoundland by Google satellite imagery and may or may not use LiDAR. THere is the link:

http://www.cbc.ca/news/canada/newfoundland-labrador/vikings-newfoundland-1.3515747 

The archaeologist, Sarah Parcak, who found it specializes in finding sites using satellite imagery. 

I also know that in Belize, LiDAR was used to map the area around Caracol, a big important Maya site which was already excavated. References for that would be Jaime Awe, Diane and Arlen Chase. Images can be found on Google.

In Guatemala LiDAR would be useful to map the Peten jungle where there are still many sites unmapped but such mapping is expensive, so it has not carried out yet. Most uses of LiDAR in Central America have been to map existing sites as far as I know.

Good luck,

Olga

LiDAR - also Airborne Laser Scanning (ALS). There has been a lot of new work in this field in recent years, and many of the papers are available here or on Academia. LiDAR has been used to detect sites in forests, under water, and in open areas. These are just a few examples - you will find much more in their reference lists.

Chase, A.F., Chase, D.Z., Weishampel, J.F., Drake, J.B., Shrestha, R.L., Slatton, K.C., Awe, J.J. and Carter, W.E. 2011. Airborne LiDAR, archaeology, and the ancient Maya landscape at Caracol, Belize. Journal of Archaeological Science 38(2):387-398.

Doneus, M. and Briese, C. 2006. Full-waveform airborne laser scanning as a tool for archaeological reconnaissance. In From Space to Place. Proceedings of the 2nd International Conference on Remote Sensing in Archaeology. BAR International Series 1568, edited by Stefano, C. and Forte, M., pp. 99-106. Tempus, Oxford.

Doneus, M., Briese, C., Fera, M. and Janner, M. 2008. Archaeological prospection of forested areas using full-waveform airborne laser scanning. Journal of Archaeological Science 35(4):882-893.

Doneus, M., Doneus, N., Briese, C., Pregesbauer, M., Mandlburger, G. and Verhoeven, G. 2013. Airborne laser bathymetry – detecting and recording submerged archaeological sites from the air. Journal of Archaeological Science 40(4):2136-2151.

Wendy, very interesting is this book collecting results from Czech Republic. https://www.academia.edu/3287449/Archeologie_a_leteck%C3%A9_laserov%C3%A9_skenov%C3%A1n%C3%AD_krajiny_Archaeology_and_Airborne_Laser_Scanning_of_the_Landscape

Thank you all. I have 1m resolution Lidar, and I am looking for signs Native of American encampments in a high-probability landscape. Unfortunately, these were very transient encampments, not cities or towns, so they may have left little signature on the ground.

Wendy,

You are correct that most hunting stations and specialized extraction camps do not leave evidence that can be seen by LiDAR manipulation. In certain environmental locations, though, it can. In Florida there are recurrent temporary hunting stations in dense palmetto areas that were hacked out by Native American so efficiently that thousands of years later the palmettos have not grown back. In swampy areas a "best location" campsite might have shallow ditches dug to improve drainage. In very hilly terrain, benches can be flattened to improve a recurrent campsite. There also is a method to identify cliff detachment mass-wasting that  might be able to identify old lithic quarry sites by the angularity of the deposits.

I assume that you have already used landform, slope, and distance to water to select high-probability site locations within the terrain. You are aware that it is critical to develop a range of LiDAR palettes? Each range and frequency can draw out different detail about the landscape. I normally cycle through about 30 palettes that I have developed when looking at a parcel.

you can see this page :

http://www.inrap.fr/des-demarches-innovantes-sur-le-terrain-et-en-laboratoire-9849

Wendy, in Finland LiDAR is applied in detecting mainly modern era structures like tar pits and several kind of war structures. But it is also very useful in detecting hunter-gatherer sites with pithouses. The resolution of LiDAR (2 m resolution) is enough for spotting pithouses larger than 4-5 meters. I'll try to attach here an example from northern Finland. The circles are depressions up to 10 m in diameter (pithouses c. 4000-3000 calBC) and in a small island in the right hand of the picture you can see a row of pithouses, a much larger feature. If I understand correct, you have also hunter-gatherer pithouses in the northern parts of America. Maybe this information is for some use to you.

With the best, Petro

Depending on the quality of the LiDAR point cloud (i.e., how many of the points within a square meter are acual ground points) it is possible to build models at resolutions of 0.5x0.5m, or even more finegrained. A couple of examples from Northern Norway. Based on a set with a resolution of 3-5 points on the ground pr square meters we have built a model with a resolution of 0.25x0.25m where we are able to spot even quite vague structures. In another area we used a dataset with 5-8 points on the qround to build a 0.25x0.25m model as well as several smaller models as finegrained as 0.125x0.125m. The last example is an area with 10+points on the ground pr square meter, a density that has allowed building all the above mentioned resolutions as well as a test of a small area 0.06x0.06m. It is important to be aware that as the resolution gets ever more finegrained, the resulting model size grows exponentionally. building models of large areas with a very fine resolution is therefore computationally more intensive, and at some point becomes a pointless exercise unless smaller areas area picked for more finegrained analysis. The 0.25x0.25m models mentioned can be considered our "standard" resolution when building models of a new dataset/area. It is useful to get a quick overview, is able to spot hunting pits, most housegrounds, etc. Depending on the number of points on the ground of the original dataset, it can even be used to spot some vaguer structures. For datasets with many points on the ground the more finegrained models can even be used to see very vague structures like graves and early stone age housegrounds.

An alternative approach that does not necessarily require more finegrained models is to use methods other than hillshade such as Sky View Factor (very useful to spot any structure with a depression) or Openness positive/negative (good at spotting raised features). There is a tool called Relief Visualization Toolbox available from:

http://iaps.zrc-sazu.si/en/rvt#v

This can perform the mentioned analysis using DEMs - as well as hillshades etc. It is freely downloadable, and there is also a lot of documentation available.

all the best, Jan Ingolf

Jan,

While I do 3-D rendering of LiDAR data, I often find than cycling through complex color palettes designed to enhance features works best to initially find things. I have tried hillshade, but would rather 3-D myself for more control. In the U.S. if we are using available point cloud data, often the best we can get is 5m res. However, 1m is the standard. Wendy said she had 1m resolution LiDAR, but did not say if that was processed and packaged LiDAR or if she processed the data herself. as I previously noted, when possible I render at 0.25 or 0.3 meter.

I have to take this opportunity to advise Wendy and others about something I have encountered in the U.S. In a local river floodplain behind my house in Louisiana there is an historic earthen feature that I strongly suspect was a gristmill/sawmill dam and flood diversion structure. It measures approximately 3m high, 8m at the base, and is some 275m long. This large feature is not present in the LiDAR. The company that was hired by the government agency of record to process the point cloud data "eliminated" perceived "data errors". Meaning that if they saw a straight line, arc, circle, square, or rectangle in the data in a location such as a forest, floodplain, marsh, open field, etc., it is very possible that they edited it out of the data. We also looked at seven previously recorded gristmill/sawmill sites across Louisiana to see what the LiDAR (same processing company) revealed. All of these mill sites had earthen dams, some only 0.3m to 0.6m high. The LiDAR only showed cultural features at two of the mill sites and those had extant mill ponds. Those mills whose dams did not still retain water did not register and it is assumed that the features also were edited out of the point cloud. That company is now closed and the original data unavailable for reprocessing.

Here's a useful source you can download:

https://www.historicengland.org.uk/images-books/publications/light-fantastic/

Mr. Hicks,

Thank you for the link! I have many technical publications on LiDAR, but clients are always asking for a simple explanation of what it can do for them. I have come up with a "short" 3/4 page explanation, but I can now refer them to this book.

JAG

Thank you all again. This is a great discussion! I have pre-processed data at the 1m resolution, but I also have the raw point cloud and can process data myself. I find that it is difficult to see things with my eyes on the 1 m hillshade, but it might help to re-process the data at a finer resolution. I like James' and others' suggestion of creating different color palettes to use my landscape variables to highlight possible areas. I have been using my slope dataset this way for sure. I'll have to explore the 3-D viewing option as well.

If you have the 1m model in the shape of TIF or similar files, try processing it with the Relief Visualization Toolbox (RVT) I mentioned. Even at 1m the Sky View Factor and Openness methods should be able to produce some results.

Depending on the point density of the raw point cloud, reprocessing at 0.5x0.5m or 0.25x0.25 could also be an option. But I would definately try RVT first!

Jan. Thanks so much! I will look into that.

Hello Wendy,

The "rediscovery" of the ancient Cambodian city of Mahendraparvata through the use of LiDAR, reported in June 2013, got quite extensive media coverage at the time (e.g., http://www.dailymail.co.uk/sciencetech/article-2342339/Cambodian-lost-city-using-revolutionary-scanning-technology.html ).  The research paper by Evans et al. on the rediscovery was published in PNAS during June 2013: http://www.pnas.org/content/110/31/12595.full  .  Lots of great images on both of these sites; the Evans et al. (2013) paper has a nice, extensive list of references, including several on the archaeological applications of laser scanning and remote sensing.  Hope this proves of some use!

Wendy,

In Louisiana all of our recorded archaeological site boundaries have been digitized and converted into ESRI shape files so that researchers who have access to the information can bring them into their project. If you talk with your State Historic Preservation Officer (SHPO) and describe what you are trying to do, they might allow you access to the site data for a few tracts of land. If so, you can display those site locations and look for clues to what you might find in the LiDAR data for each of those types of sites in the database. This could be features, or it could be as simple as a particular landform, area and slope, elevation, etc. However, given a sample to inspect, this might tell you whether using LiDAR to locate or predict sites is feasible in your area.

Reminds me of an associate who calculated the average depth, square meter size, and number per square mile for sites buried under sediments along the Red River in order to quantify the chances of finding a site by deep auger hole testing. The conclusion was that you were more likely to find more sites by chance than by systematic survey. Good ideas don't always pan out.

Good points...

Wendy,

Thanks. Actually, because I have been doing site prediction for decades, I haven't done what I recommended. However, since I have a lot of LiDAR that I have processed, I plan on looking at some known site locations myself to see what I can determine.

For processing raw point clouds, including building DTM/DEM/DSMs+++ also check out lastools:

https://rapidlasso.com/lastools/

Can be integrated with QGIS, ArcGIS and ERDAS Imagine, or be run as stand-alone commandline tools (or actually also with its own GUI). Recommended!

Jan,

I use lastools. Too bad there is no manual.

James,

yes  I agree a manual would be nice. But I have come a long way with the individual READMEs plus more importantly the various support options available through the website. I have also on a couple of occasions contacted Martin Isenburg directly with prompt and quality reponses. So while there might be a steep learning curve, there is also help to be found.

Dear Wendy,

you may want to consult the following publications,

Best,

Ladislav

Štular, B., Kokalj, Ž., Oštir, K., & Nuninger, L. (2012). Visualization of lidar-derived relief models for detection of archaeological features. Journal of Archaeological Science, 39(11), 3354-3360, doi:http://dx.doi.org/10.1016/j.jas.2012.05.029.

Bewley, R. H., Crutchley, S. P., & Shell, C. A. (2005). New light on an ancient landscape: lidar survey in the Stonehenge World Heritage Site. Antiquity, 79, 636–647.

Devereux, B. J., Amable, G. S., Crow, P., & Cliff, A. D. (2005). The potential of airborne lidar for detection of archaeological features under woodland canopies. Antiquity, 79, 648–660.

Devereux, B. J., Amable, G. S., & Crow, P. (2008). Visualisation of LiDAR terrain models for archaeological feature detection. Antiquity, 82, 470–479.

Doneus, M., Briese, C., Fera, M., & Janner, M. (2008). Archaeological prospection of forested areas using full-waveform airborne laser scanning. Journal of Archaeological Science, 35(4), 882-893.

Wendy, here are a few more references.

Hope it helps!

Cheers,

Tiago

http://www.sciencedirect.com/science/article/pii/S0305440310003286

http://www.sciencedirect.com/science/article/pii/S0305440306001701

http://onlinelibrary.wiley.com/doi/10.1002/arp.294/abstract

http://onlinelibrary.wiley.com/doi/10.1002/gea.20281/abstract

Thank you. It is much appreciated!

Dear Wendy, 

some more references:

Crutchley, S. & Crow, P., 2010. The light Fantastic: Using airborne laser scanning in archaeological survey. https://content.historicengland.org.uk/images-books/publications/light-fantastic/light-fantastic.pdf/ 

you can also find a discussion on the technique and its application by English Heritage  in: Chavarria, A. & Reynolds, A. (eds.), 2015: Detecting and understanding historic landscapes. PCA studies, 2.

We also applied the technique in Brussels to better define the outline of the ditches and earthen walls of the Neolithic site of Boitsfort (Belgium), which is today covered by a dense forest. see: Devos et al., in press. The conservation and degradation of archaeological soil features in Flandres and Brussels: the example of Watermaal-Bosvoorde. Conservation and Management of Archaeological Sites.