GPR for Archaeology

Collecting, processing and interpreting ground-penetrating radar (GPR)


GPR Workshop

The 2021-2022 Advanced GPR Interpretation Workshop is underway Many thanks to GSSI and California State University Sonoma (as well as other sponsors) for making this workshop happen.  

This year Lauren Couey (GSSI) is my co-workshop organizer and Radan specialist. 

 

 

 

 

 

Here are the recordings to the workshop sessions:

Background sessions:

  • Dec. 7, 2021:  basics on what to do first with GPR data when returning to the field:  Time zero, basic processing, reflections, how to describe reflections, and how to determine velocity from hyperbola fitting.

https://mediaspace.du.edu/media/t/1_tv7g1tff

  • Dec 15, 2021 :  Short session on GPR Viewer with more work on velocity, topographic adjustments, how to produce images from profiles, how to annotate those images for reports.  Also Surfer basics on gridding, image making and annotations of maps

https://mediaspace.du.edu/media/Dec.%2015%2C%202020%3A%20Short%20session%20on%20GPR%20Viewer%20and%20Surfer/1_ztyjud89

  • Dec 17, 2021: Basics on amplitude slicing.  How to determine slice thicknesses, and what resolution is in various frequencies.  How to determine what a map is showing, and how to adjust maps for various amplitudes.  Also basics on comparing profiles to maps, and how to make those in both Surfer and Radan:

https://mediaspace.du.edu/media/Amplitude+slicing/1_1zqxorop

The General Sesssions: 

  • Jan 7, 2022 First day of workshop…introductions and where we are going with Larry ideas. Introduction to the Ecuador Inca Temple dataset.

 

 

 

 

 

https://mediaspace.du.edu/media/Jan%207%2C%202022%20First%20day%20of%20workshop%E2%80%A6introductions%20and%20where%20we%20are%20going%20with%20Larry%20ideas.%20/1_bmdxuopy

  • Jan 14, 2022:  Ecuador grid and introduction to frequency filtering.

 

 

 

 

 

 

 

https://mediaspace.du.edu/media/Jan%2014%2C%202022%3A%20%20Ecuador%20grid%20and%20introduction%20to%20frequency%20filtering/1_qk40pjsl

  • Jan 21, 2022:  Baudes, France and introduction to Tanuri site (frequency filtering for Roman villa and Medieval church).

https://mediaspace.du.edu/media/Date%3A%20Jan%2021%2C%202022%20Baudes%2C%20France%20%20and%20introduction%20to%20Tanuri%20site%20in%20Arizona/1_ltwxf9of

 

 

 

 

Jan 28, 2022: Tanuri, Arizona:  a 900 MHz data set in both x and y of a “pre-Classic” Hohokam house.

https://mediaspace.du.edu/media/t/1_f8u6f5rm

 

 

 

 

 

 

  • Feb. 4, 2022: Late Pleistocene Portugal:  mapping fluvial channels in the context of a Late Ice Age hunting site. 

Below is the recording of special session on picking the bedrock horizon, and then producing 3-D images of that buried surface, which is a map of the ancient landscape at the end of the Ice Age:

https://mediaspace.du.edu/media/t/1_9y0afwp7

 

 

 

 

 

 

This is the full session where everyone shows their results.  Very interesting mix of methods from many participants. Also an introduction to next week, which is a merger of GPR and magnetics:

https://mediaspace.du.edu/media/Portugal%203-D%20surface/1_85zzaf02

  • Feb 11, 2022: Connecticut USA:  a 17th century farming community that was covered in flood sand about 1705.  Integration of GPR analysis and magnetics. 

Below is the short session on merging magnetics and GPR (the “Larry” method of comparing magnetic readings to GPR profiles and amplitude maps, which is very “non traditional”):

https://mediaspace.du.edu/media/Special%20session%20on%20merging%20magnetic%20readings%20and%20GPR%20profiles%20and%20maps/1_x3dn7gse

 

 

 

 

 

Here is our group analysis of features from Hollister, with many different data processing and interpretation methods.  With an introduction by Dave Leslie on the recent excavations from the site, which provide an important template forthe interpretations

https://mediaspace.du.edu/media/Hollister%20site%20merging%20GPR%20and%20magnetics/1_1ut2gwxa

  • Feb 18, 2022: Laetoli footprints:  famous Tanzania hominid site with a 2.6 GHZ antenna for very high resolution

a short session on how to process and interpret the prints:

https://mediaspace.du.edu/media/Footprints%20some%20basic%20GPR%20thoughts/1_cv9aysnu

 

 

 

 

 

 

 

Our joint interpretation of the prints, with many different methods (some good, some not so great…but good tries!) that we used:

https://mediaspace.du.edu/media/GMT20220218-160005_Recording_gallery_3200x1700.mp4/1_874ysok4

 

  • Feb. 25, 2022: Cueva Peluda Spain:  Neanderthal cave where the ceiling and floor both must be mapped, and the volume of the void space determined. 

Some background on methods to pick horizons, convert time to depth and then produce 3-D volumes and images of the cave:

https://mediaspace.du.edu/media/cave%20velocity%20analyses%20and%203-D%20volumes/1_frtwbb3m

 

 

 

 

 

 

 

Our joint interpretation today of the cave with estimates of the volume.  Also an introduction to the Rillito Fan project for next week

https://mediaspace.du.edu/media/cave%20analysis%20of%20floor%20and%20ceiling%2C%20and%20introduction%20to%20Rillito%20Fan/1_t9pa2ewu

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  • Mar 4, 2022: Rillito Fan, Arizona:  an irrigation system associated with an “Early Agricultural” village on the banks of the Santa Cruz River near Tucson. 

short session on placing the canal into space and producing 3-D images

https://mediaspace.du.edu/media/canal%20picks%20and%203-D%20images/1_7r43lv5z

 

 

 

 

 

The analysis of the canal, and introduction to the mystery grid

https://mediaspace.du.edu/media/canal%20analysis%20and%20introduction%20to%20mystery%20grid/1_rsjzj11i

  • Mar 11, 2022: The mystery grid. A nice GPR and magnetic grid from a spot in southern England.  The final exam! 

Results of the mystery grid analyses

https://mediaspace.du.edu/media/final%20workshop%20day%20with%20results%20of%20the%20mystery%20grid/1_02aeo483

 

 

 

 

 

 

Here are the participants of the 2022 Workshop. 

Andrew Heller SEARCH Inc.
Claiborne Sea U of Alabama
David Cranford Assistant State Archaeologist, NC Department of Natural and Cultural Resources
David Givens Director of Arcaheology, Jamestown Rediscovery
David Leslie Archaeological and Historical Services Inc.
Ethan Ryan Project Manager, Cannon Heritage
Gano Perez GIS Cultural Specialist, Muscogee (Creek) Nation
Iraida Rodriguez NPS Southern Arizona Office
Jean-Christophe Ouellet Dept. of Anthropology, University of Montreal
Jennie Sturm Statistical Research, Inc & University of New Mexico
Jeremy Pye PI, Cultural Resources Analysts, Inc. 
Jonathan Alperstein Dartmouth College
Kevin Nolan Ball State University
Mary Beth Fitts Assistant State Archaeologist, NC Department of Natural and Cultural Resources
Molly Cannon Director Mountain West Center, Utah State University
Robert Chartrand Chartrand Geoarchaeological Solutions, LLC
Scott W. Hammerstedt Oklahoma Archaeological Survey; U. of Oklahoma
Seth Van Dam Gray & Pape Heritage Management
Sheldon Skaggs Bronx Community College City University New York
William Chadwick Indiana University of Pennsylvania
Bryan Mischke  Cal State Sonoma, California
Michael Konzak Cal State Sonoma, California
Maria Iancu Anglia Ruskin University, Cambridge, UK. 
Zafeiria Roumelioti University of Patras, Greece
Evrim Tütünsatar Isparta Uygulamalı Bilimler Üniversitesi, Turkey
Thomas Fenn U of Oklahoma
Sean Farrell SEARCH Inc.
Christopher Peske Sonoma State University
Dana Kollmann Townson University
Samantha Kirkley Southern Utah University
Peter Masters Cranfield University, UK
Katherine Beames U. of Alberta
Francisco Peralta Belmonte Asunción, Paraguay

Below are all the recorded sessions for each week of the workshop from 2021:

March 12:  Caves and cave fill.

https://mediaspace.du.edu/media/GMT20210312-155832_Lawrence-C_1920x1200/1_aba3kda9

March 5, 2021:  Arne Andersen Stamnes:  The Norwegian stepped frequency system, and introduction to caves.

https://mediaspace.du.edu/media/GMT20210305-160218_Sala-riuni_1920x1080/1_46oaneq9

Feb. 26, 2021: Graves and gridding complexities.  With Peter Leach from GSSI

https://mediaspace.du.edu/media/Graves+and+gridding+complexities+2.26.21+Speaker/1_fesuo1ay

Feb. 19, 2021:  Footprints/Mystery 1619 grid

https://mediaspace.du.edu/media/GMT20210219-160117_Sala-riuni_1920x1080/1_qov2mxr7

Feb. 12, 2021:  Immo Trinks:  The Austrian multi-channel method

https://mediaspace.du.edu/media/GMT20210212-160404_Pers–nlic_1920x1200/1_kxysro6g

February 5, 2021:  Coopers Ferry 3-D:P how to horizon pick and make 3-D surfaces

https://mediaspace.du.edu/media/GMT20210205-160201_Lawrence-C_1920x1200/1_f88oiwj5

February 3, 2021:  Special session on 3-D profile analysis

https://mediaspace.du.edu/media/GMT20201217-215715_Lawrence-C_1344x728/1_ajl9tj60

Jan. 29, 2021:  Baudes, France and the application of data filtering and migration:

https://mediaspace.du.edu/media/GMT20210129-161447_Lawrence-C_3840x2060/1_jbyktsgl

Jan. 28, 2021:  Special session on profile analysis

https://mediaspace.du.edu/media/GMT20201214-220510_Lawrence-C_1344x728/1_z3zgyp1h

Jan 22, 2021.  Tanuri 2:  Analysis of a Hohokam site in southern Arizona

https://mediaspace.du.edu/media/GMT20210122-155923_Lawrence-C_3528x1200/1_fcy0prct

Jan 18, 2021: migration and filtering and basic slicing

https://mediaspace.du.edu/media/GMT20210118-195948_Lawrence-C_1600x768/1_z26j0mgo

Jan. 15, 2021: Tanuri 1: our start on studying a Hohokam site in southern Arizona:  basic profile analysis and migration

https://mediaspace.du.edu/media/GMT20210115-155752_Lawrence-C_1920x1080/1_sq8au4i1

Dec. 17, 2020: pre-workshop basic amplitude slicing and profile analysis

https://mediaspace.du.edu/media/GMT20201217-215715_Lawrence-C_1344x728/1_ajl9tj60

Dec. 14, 2020: pre-workshop basic GPR

https://mediaspace.du.edu/media/GMT20201214-220510_Lawrence-C_1344x728/1_z3zgyp1h

Here are this winter’s participants who made it to the end.

Adam S. Wiewel,
Midwest Archeological Center; National Park Service
Lincoln, Nebraska


Sam Roberts
Met Geo Environmental Ltd and Met Engineers Ltd
Leeds, UK


Nikos Papadopoulos
Lab of Geophysical-Remote Sensing
Rethymnon, Crete, Greece


Rory Becker
Eastern Oregon University
La Grande, Oregon USA


Kris Lockyear
University College London, UK


Adolfo Martinez
Monterrey, Mexico

Mohammed Mohsensali
Bagdad, Iraq


Emma St. Pierre
Virtus Heritage
Dunedin, New Zealand


Luca Piroddi
Università degli Studi di Cagliari
Dipartimento Ingegneria Civile, Ambientale e Architettura
Cagliari, Italy


Arne Anderson Stamnes
Norwegian University of Science and Technology
Trondheim, Norway


Rok Plesnicar
Wessex Archaeology
Old Sarum Park, Salisbury, Wiltshire SP4 6EB


Robert Ryndziewicz
University of Warsaw, Poland

Peter Masters

Cranfield Forensic Institute
Cranfield University, UK


Jim Glenister
John Moores University
Liverpool, UK


Richie Villis
Archaeological Services
Durham University


Kristoffer Dahle
Norwegian University of Science and Technology
Trondheim, Norway


Kendra L. Maroney
Kalispell Tribe, Washington, USA

İnci Nurgül Özdoğru
Eurasia Institute of Earth Sciences, Istanbul Technical University,
Istanbul/Turkey


Mark R. Schurr
University of Notre Dame
Notre Dame, IN 46556 USA


Heather Gimson

Earthsound Geophysics
Drumagh, Claremorris, Ireland


Elle Lillis
Virtus Heritage, Pottsville, Australia


Huthaifa Qawasmeh
Amman, Jordan


Adrian Serbanescu
Bucharest, Romania


Katherine Gadd
University of Alberta
Edmonton, Alberta, Canada

and a few comments after it was all over:

• I learnt a great deal in this workshop. These last three months have been amazing. Many, many thanks to Larry for spending so much time doing this. I enjoyed being a grad student again!
• I also want to express my enormous gratitude to Larry. This workshop changed (improved) my life, not only professionally but also personally, in a very surprising way that I had never imagined before. In these 3 months I was always looking forward to Friday to have these meetings. Now, making a compilation of what has happened, I realize that many times we feel in a separate world but that in reality there are many people like us and finally someone (Larry) had the courage to meet us.
• In this last zoom meeting, we laughed a lot more than at any meeting before. Maybe because we are sad and trying to hide our feelings. I do not have words to describe my feelings now. Larry, thank you for any minute you spent teaching us GPR. Today, I am a new person who can understand how GPR works. My view on the interpretation of GPR reflections is developed. all that because of you. And the most important thing that I get from this workshop is all of you. I meet new wonderful peoples and worked with them for three months. Thanks Larry to give me this opportunity to participant in this workshop.
• Thank you for organizing this. It has been wonderfully instructive, and I have learnt more than I ever imagined there was to learn. It has also been great to finally feel like I am part of a GPR community after floundering around on my own. I appreciate this group on many levels!
• I’m very proud, happy and grateful for all that I learned and not only on my own toolbox but all the GPR-related concepts (on both which I feel now more self-confident and interested to go deeper): It has been a fantastic didactic experience of learning by doing which I hadn’t done since my earlier studies in architectural engineering and not in all my PhD and postdoc experiences in geophysics.
• Especially our last session was really amazing and shocking if compared from where we started, especially the part of the sedimentary filling of the cave… showing how reality can be far from standard interpretations, sometimes (otherwise they shouldn’t be standard or common!).
• It’s been a real pleasure, and I have gotten a much better grasp on how to use GPR for archaeological analysis, which in turn will lead to getting better at interpretation. I am very impressed by the results, application and analyses presented by all the participants. Well done everyone!
• I have very much enjoyed this workshop every Friday. It has given us food for thought over the winter months. I have learnt a great deal from the ‘Master’. I have learnt new ways to analyse and interpret the data using other software than I knew.
• Today is our last day and I will miss our interactions on looking at the homework you have provided us with. This has been challenging but has reaped its rewards as well by understanding how to achieve the results and looking at the data in new ways.
• Linking up with everyone around the world has been great and I hope we continue to keep in touch with each other. Beyond GPR Workshop ‘Larry Style’, this will be great to continue with others who wish to join our get together every couple of weeks or once a month and hopefully Larry will be able to join us.
• Larry, this course has been a revelation. I’ve gone from being a guy who used some basic filters because I read about them somewhere to make slice maps that I looked at for possible archaeological patterns. Then I became someone who looks at individual profiles, has a vocabulary to describe them, can understand how actual features in the ground might be producing the profiles, filtering based on what actually needs to be clarified (less might be better when you understand what you are seeing), and producing slice maps that I can relate to expected features and not just patterns of unknown origin. And now, this week, I am a guy who can look at an individual trace and see useful stuff like phase changes and know what they mean.
• Thanks to Larry for giving up his time and organizing this venture. It has been a pleasure to participate and to be pushed to explore data in different ways and from different settings. The course has been invaluable, and I have a better understanding of GPR processing and therefore interpretation and I already implementing the knowledge in recent surveys. Experiencing different programs and what they produce has also been very interesting, while getting a full knowledge of Larry’s program has been fantastic.
• Thank you, Larry, for letting me join in this workshop, I’m the only one who doesn’t have any background in archeology or geology, but I learned so many things from you and the others. When we started this workshop, I thought it would take a long time to finish, but unfortunately today it’s finished like “speed of light”.
• Thank you, Larry, you’ve done an incredible service to all of us in making this workshop available. Thank you for your time and efforts, you’ve provided many different types of datasets for us to explore and talk about GPR. You gave me an appreciation for all aspects of GPR, different perspectives that I hadn’t considered, and knowledge and confidence to approach the data in a more open/less frigid way. I learned an immense amount, and really enjoyed the different datasets, listening to others, and the process itself.