dart: fry progress so far 070711

School of ComputingFaculty of Engineering

Progress UpdateA quick look at the DART project so far, the preliminary geophysics and the FlashRes64

Robert Fry

Division of Archaeological, Geographical and Environmental Science

PhD

• Research into geophysical seasonality has begun

• Preliminary testing of the FlashRes64 ERI instrument

• Development of an extraction program in Python begun

DART

• Sites for investigation have been found

•Preliminary geophysical (Fluxgate Gradiometer) surveys

• Excavation of sites and installation of TDR probes (Cirencester)

• Testing of CMD EM with possible addition onto the geophysical methodology

Since the last meeting…. 

Preliminary Geophysics

Harnhill, Cirencester

Fluxgate Gradiometer

Results

Harnhill: Rathill

Interpretation

Harnhill: Rathill

Fluxgate Gradiometer

Results

Harnhill: Quarry Field

Harnhill: Quarry Field

Harnhill: Cherry Copse

Fluxgate

Gradiometer

Results

Harnhill: Cherry Copse

Preliminary GeophysicsDiddington, Cambridgeshire

Fluxgate Gradiometer

Results

Diddington 1

Interpretation

Diddington 1

Fluxgate Gradiometer Results

Diddington 2

Interpretation

Diddington 2

Fluxgate Gradiometer Results

Diddington 3

Interpretation

Diddington 3

Fluxgate Gradiometer Results

Diddington 4

Interpretation

Diddington 4

New Geophysics at Cherry Copse…

Cherry Copse

Quarry Field

Quarry Field

TDR installed at Cirencester (Quarry Field)

FlashRes64• New technology – usually a geological/hydrological investigation.

•C.15,000 measurements in 15 minutes

• C.60,000 measurements in 50 minutes

• Production of a ‘small-spacing rig’ for archaeological problems

• Production of a lab rig for specific testing (MSc Dissertation research)

FlashRes64 – Rough Guide

Long surveys

Temple Newsam - Leeds

• 1m probe separation

Archaeological Problems: Broughton

Ditch

20cm spacing = 12.6m transect

Ditch at top = C.1.4m wide

Archaeological Problems: Broughton

Ditch

Quarry Field, Cirencester

• 20cm probe spacing (12.6m per survey)• Roll-on survey (two surveys per traverse)• Traverses 2m apart

Area of overlap

1

4

5

8

9

2

3

6

7

10

Survey no. Traverse no.1

2

3

4

5

Quarry Field: Cirencester

2D profiles

Surveys 1+2

(Traverse 1)

Surveys 3+4

(Traverse 2)

Surveys 5+6

(Traverse 3)

Surveys 7+8

(Traverse 4)

Surveys 9+10

(Traverse 5)

3D depth slices

Archaeological application: FlashRes Extractor program• Written in Python – very much still in progress

•Claims: 0.5m, 1m, 1.8m depth ranges

• Intercoil spacing: 0.32m, 0.71m, 1.18m

• Built in EM inversion

• Apparent conductivity (resistivity) as well as in-phase response

•Tests in Bradford Amphitheatre, and Harnhill, Cirencester

CMD MiniExplorer

• Samples collected 0.5s

• Zig-zag traverses 0.5m

• 20x20m grid

• In-phase response to left

• Apparent resistivity to right

CMD MiniExplorer Bradford

Service pipe (Photo: Andy Parkyn)

• Samples collected 0.5s

• Parallel traverses 0.5m

• 20x20m grid

• In-phase (ppt) response to left

• Apparent resistivity (ohm.m) to right

CMD MiniExplorer Quarry: Cirencester

• Samples collected 0.5s

• Parallel traverses 0.5m

• 14x20m grid

• In-phase (ppt) response to left

• Apparent resistivity (ohm.m) to right

CMD MiniExplorerCherry Copse: Cirencester

‘Publications’