Modern Technology for Ancient

Analysis: LiDAR at Aztalan State ParkBy Colleen A. Hermans

Image by Randy Roberts

Overview

Why is Aztalan important? LiDAR specs for the area Examples and comparisons of

images Benefits of using LiDAR for archaeology Looking towards the future

Platform Mound and Palisade WallImage from the Wisconsin Historical Society

Aztalan: 1000 – 1200 AD,

Middle Mississippian Village

Cahokia: Cultural Center from 700 – 1400 AD; peak

1050-1200 AD

Image from www.legendsofamerica.com

Jefferson County

Aztalan

LiDAR data and specs used

LiDAR flown over north half of Jefferson County in 2004 by Merrick and Company

Products derived: 2’ contours, DTM, Ortho, planimetrics

TINs created from the 2’ contours used by our floodplain program

Ann Runyard from DNR extracted the nodes and created a seamless TIN from 2 overlapping TINs

Mark Dudzik, DNR archaeologist, consulted

Contours derived from

using a transit station

Time intensive 1 week, all day Need to be nearby

in order to survey on foot

Image courtesy of Mark Dudzik, DNR

2’ Contour map

of AztalanPrevious transit station contour area

Aztalan 2X vertical 1. Northwest

Mound: built in 3 stages

2. Southwest Mound:

largest mound 3. Natural gravel

knoll 4. Remnant mound 5. Row of Conical

Mounds

1

2 3

4?

5

?

Southwest platform

Southwest platform mound

through stockade

Northwest platform mound

N

N

Image from the Wisconsin Historical Society

Image from the Wisconsin Historical Society

Image from the University of Wisconsin-Milwaukee, Department of Anthropology

Miles0 0.20.12008 NAIP

DOP vs. LiDAR: Conical Mounds

Conical Cross Sections

Conical Mounds

Image from the Wisconsin Historical Society

N

±

East Bank

Erosion pothole

East Bank Cross Section Data

DOP vs. LiDAR

LiDAR advantage: Penetrates foliage

2008 NAIP

Benefits of LiDAR

Monitor/preserve known existing sites over a large terrain (that can be difficult to navigate)

Discover new sites Depending on the LiDAR density, can

be very accurate Contour lines – more time efficient

than using a total station LiDAR is to mound sites as aerial

imagery is to Nazca lines in Peru

Example of better LiDAR

Image from New York Times, courtesy of Caracol Archaeological Project

Another Example: Effigy Mound National Monument by Continental Mapping; found new mound; 15 cm vertical accuracy

Future of LiDAR and Archaeology

Sharing of data across professions and agencies

Statewide data! CGI of Aztalan

Create 3D mound depictions similar to creating buildings in cities

Image courtesy of Friends of Aztalan

Questions?

Colleen.Hermans@wisconsin.gov

Image by Daniel Seurer