Managing archaeological surveys through geospatial information
David Ketz
The 106 Group Ltd.
370 Selby Avenue
St. Paul, MN 55102
Abstract
The 106 Group has designed a method of managing geospatial data, enabling new levels
of control, accuracy, and information for archaeological surveys. Their approach
standardizes the terms and techniques used among multiple agencies, resources, and
states and effectively integrates their operations through GPS, GIS, and Internet
technologies. This process allows navigation without staking, daily collection and
dissemination of data, and compressed preparation time for reports while providing
valuable management information.
Introduction
Archaeology is a science that studies the mysteries of the past. However, trying to
manage and quantify the information, time, and costs involved in performing an
archaeological survey can be one of the greatest mysteries of all.
The 106 Group has designed a method of managing geospatial information that has
introduced new levels of control, accuracy, and data collection to archaeological surveys.
This method includes applying the latest technologies in Global Positioning Systems
(GPS), Geographic Information Systems (GIS), and the Internet. GIS professionals,
archaeologists, project managers, and pipeline companies have all welcomed this
approach as a solid step forward in collecting data, saving time, and lowering costs.
In this paper, I intend to present a detailed explanation of our methods and show the
advantages of this process for archaeologists, and, especially, the pipeline industry.
Concept
The approach integrates the latest geospatial technologies with traditional archaeological
survey methods to collect, process, and share sub-meter spatial information. The
methodology involves four key components.
- Navigation and data collection
- Data processing and analysis
- Consolidation of source data
- Management of project information
Navigation and data collection
Survey preparation
The first step in the survey process is to convert pipeline centerline data into GPS
navigational waypoints. To do this, a unique waypoint is generated at every three
hundred feet on the pipe centerline. A GIS is used to plot existing and proposed
pipelines, survey corridor, and navigational waypoints onto both USGS topographical
and aerial photographic base maps to facilitate on-the-ground navigation.
The second step in the process is to define a data dictionary. The data dictionary is
designed to collect and integrate all of the reporting needs of the State Historic
Preservation Offices and federal agencies that will be reviewing the project. When
working on a multi-state project, the data dictionary is designed to integrate different
terminology under a common identifier so as to create a seamless mapping and reporting
system. It is also designed to capture information that will complete coverage tables,
automate map production, and provide management information.
The third step in the startup process is to train each archaeology team in the use of these
methods and equipment. Each crew is equipped with a Trimble Pathfinder ProXRS
with Omnistar satellite service. The instructional process includes both classroom and
hands-on training with experienced instructors.
Navigation without staking
The first advantage of this approach is that the archaeologists can conduct their survey
without a staked centerline, helping to lower overall project costs and minimize
landowner intrusion.
A typical day of a survey begins with the senior archaeologist directing the GPS operator
and crew. With aerial maps showing the line and waypoints in hand, the senior
archaeologist directs the GPS operator to stand on the beginning waypoint and center
him/her self on the proposed line. Although the GPS data collector has the waypoints
loaded, the maps carried by the senior archaeologist serve as a reality check for location
and as a place to sketch and record field observations.
Using the GPS operator as a central anchor, the archaeologist align themselves
perpendicular to the line and space themselves at the required survey transect interval.
Hand-held radios tuned to a common channel ensure that everyone is tied to a constant
flow of information.
The GPS operator obtains a reading on the second waypoint, typically 300 feet away. At
the senior archaeologist’s direction the GPS operator begins walking toward the second
waypoint and the crew moves forward as a line. When the second waypoint is reached
the GPS operator fixes on the next waypoint and so on.
Data Collection
The second key advantage of this method is the ability to collect accurate digital field
data. Archaeologists have to present a wide range of information to various state and
federal review agencies in order for a project to be permitted. The approach presented
here gathers that data more accurately and allows the archaeologists to produce their
report more quickly and efficiently than through traditional means, which can result in
earlier permitting for a pipeline company. In addition, while documenting the field data
required as part of the archaeological survey, other points can be collected to help the
pipeline company streamline its projects.
As with navigation, the collection of archaeological field data begins with the GPS
operator standing directly on the starting waypoint on the proposed centerline. The GPS
operator enters a breakpoint in the data collector prior to moving to the first waypoint.
As the survey crew sets out, the senior archaeologist states what method of survey
coverage will be used (for example, surface survey) and the GPS operator selects that
survey type from the predefined list in the data dictionary. This establishes the attributes
of what will become a polygon within a GIS. As the crew moves toward the next
waypoint, the senior archaeologist records survey data on the aerial and topographical
map and in a notebook, and these will help to serve as quality control for the GIS data.
The senior archaeologist will inform the GPS operator of significant points to record as
they move toward the next waypoint.
Archaeological data that is collected can include land access, survey methods, surface
condition and visibility, shovel test areas, site information, field observations, and
geographical and natural features (such as tree lines, fences, and valve stations).
Reference lines are gathered along roads and other distinctive features to assist GIS staff
in geo-referencing and checking field data.
Areas that warrant shovel testing are identified during the survey and recorded with GPS.
This allows archaeologists to return to exact locations for utility clearance and shovel
testing with confidence. This method of gathering field information takes minimal time
and creates a multi-path system to capture, cross-reference, and verify field information.
In addition to the archaeological data that is collected, certain additional data important to
the pipeline company and its GIS department can be gathered. For example, the GIS
technicians with the archaeological survey crew can gather digital line data or road and
stream crossing data. If a project biologist accompanies the archaeological survey crew,
wetland boundaries and other environmental data can be captured at the same time.
Since our archaeological survey crews and GPS operators are already in the field
collecting a variety of data, our approach can be expanded to meet additional data needs
of any pipeline company and their GIS staff.
Daily transfer of field data
When the crews return to their rooms at the end of the day, the GPS operator and senior
archaeologist download their data onto laptops and use a secured Internet connection to
log onto the company Intranet site. The field and GPS data is uploaded to a database
designed to capture and consolidate all project information. An e-mail is automatically
sent to the GIS coordinator and project manager in the office informing them that
particular data has been sent and is available for processing.
