digital landscapes and archaeology (peter rauxloh)

Digital landscapes and  Archaeology

Peter RauxlohMuseum of London Archaeologywww.mola.org.ukprauxloh@mola.org.uk

Improving data capture

Improving data capture

Dissemination of data

Dissemination of data

Improving data capture

Improving data capture

Improving data capture

New data capture – Remote sensing

New data capture – Remote sensing

New data capture – Remote sensing

New data capture – Remote sensing

New data capture – Remote sensing

New data capture –

Terrestrial

New data capture – Close range

New data capture – Hydrological

Spitalfields

Medieval Cemetery

On site data capture

On site data capture

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Derived  data capture

Points and attributes

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Alignments and  outlines

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Alignments and  outlines

Alignments and  outlines

Alignments and  outlines

Alignments and  outlines

Phasing and structure – a view on stratigraphy

Phasing and structure – a view on stratigraphy

Relative meets absolute

Relative meets absolute

• 1920’s toilet centre upper in cemetery• Large basement area on east side of site, • Drainage dividing ditch between main body of cemetery and church in period 17• Civil war ditch leading up to charnel house from south.• Catastrophic burial from later periods

GIS for a truncated landscape

17 1615 14

Quantifying visibility

Quantifying visibility

26.7

45.5

56.854.0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

17 1400-153816 1250-1400 15 1200-125014-1100-1200

%of cemetery truncated by area

Truncation and population extrapolation

Found Est total Period length Cemetery area

Truncated area Visible area

Period 14 1100-1200 900 3000 100 4612 2621 1991

Period 15 1200-1250 2839 5600 50 4701 2538 2163

Period 16 1250-1400 5480 7900 150 5687 2587 3100

Period 17 1400-1538 1009 1350 138 2923 780 2143

Quantifying visibility

Spatial targets, what was happening around these target?

• Charnel house appears in period 1320s • The Pulpit cross – 1390s• Relationships to the south-east end of church period X• Cannon’s infirmary period X• Cemetery changing boundary

Investigating a sacred landscape

Famine disease and distance Catasrophic

burial points 

Data as a surface 

Boundary proximity & burial type breakdown as %

01020304050607080

A B C

Within 3m of boundaryBackground

Boundary proximity & sex breakdown as %

05

1015202530354045

F M N/U

Within 3m of boundaryBackground

Boundary proximity & agecode breakdown as %

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8

Within 3m of boundaryBackground

Consecrated ground & buffer queries

Age at death period 17 Age at Death P 17 

Buffered subsets 

0

5

10

15

20

25

30

35

Pre-natal 7-11months

1-5 years 6-11years

12-17years

18-25years

26-35years

36-45years

46 ormore

Within 3m of monuments >3m From monuments

Buffered subsets 

•

An articulated version of Rocque

1746 central London map  georeferenced

to both OSGB36 and WGS84 CS

•

A point dataset of each combination of Parish, Ward and street/place  identifiable on the map.

•

A replicable methodology

MOLA Products

Challenges

•

Accuracy of the map–

Stability of Media used

–

Survey technique used

•

How to minimise the amount of new data entry

•

QA of data sets 

•

How to exploit the first accurate mapping of the area 

Principles•

Grounding the GIS work in a geographical reality

•

Exploiting / re‐purposing existing resources

•

Creating data sets that required editing rather than  re‐building to be appropriate to early or later 

mapping

The Old Bailey on line 

The Old Bailey on line

Putting the map together

Putting the map together

Putting the map together

Putting the map together

Putting the map in the right place

Putting the map in the right place

Putting the map in the right place

62% churches

Putting the map in the right place

Identifying places on the map

The geographical ‘reality’

Identifying places on the map

1Main thoroughfare ‐

outsized e.g. Holborn, Cheapside typically 20m width.  This code is also to be used for 

those roads that run around squares and similar entities.  

2 Main thoroughfare ‐

standard width (c.15m)

3 Secondary thoroughfare ‐

standard width (c.10m)

4 Tertiary thoroughfare ‐

standard width (c.6m)

5 Alley way  ‐

i.e. a narrow route running between two streets or street and place polygon (1‐2m)

6Cul‐de‐sac plus area ‐

i.e. a dead end but one which opens out into a court.  The wider area is captured as a 

polygon and will be amalgamated with class 6 streets  (typically

c.2m but up to 10 for a Mews)

7 Cul‐de‐sac ‐

i.e. a simple dead‐end. (c.2m but up to 10 for a Mews)

Identifying places on the map

Hierarchies of streets

Identifying places on the map

Places and precincts

Identifying places on the map

A Traversable network

Identifying places on the map

Identifying places on the map

A Traversable network

Identifying places on the map

The Holborn viaduct dilemma

The Holborn viaduct dilemma

Identifying places on the map

Line-polygon-buffer

Identifying places on the map

Hierarchical clipping

Identifying places on the map

Identifying places on the map

Naming places

Existing data referenced + cleaned

Generating comprehensive  data

Generating comprehensive  data

Generating comprehensive  data

Generating comprehensive  data

Filename Contents Count Type

LL_PL Places 5887 Polygons

LL_PL_POINTS Places 5887 Points

LL_PA Parishes 191 Polygons

LL_PA_POINTS Parishes 191 Points

LL_WA Wards 99 Polygons

LL_WA_POINTS Wards 99 Points

LL_PL_PA 7,121 Polygons

LL_PL_PA_POINTS Places and Parishes 7,016 Points

LL_PL_WA Places and Wards 6,711 Polygons

LL_PL_WA_POINTS Places and Wards 6,711 Points

LL_PL_PA_WA Places and parishes and wards 7,847 Polygons

LL_PL_PA_WA_POINTS Places and parishes and wards 7,847 Points

LL_PA_WA Parishes and wards 555 Polygons

LL_PA_WA_POINTS Parishes and wards 555 Points

LL_STREET_NETWORK Street network Lines

• People are subjective observers• Computers are subjective ‘observers’• Identifying bias and humanization• To be useful they must be understood

Ode to a Spell CheckerI have a spelling checker

I disk covered four my PC. It plane lee marks four my revue Miss steaks aye can knot see.

Eye ran this poem threw it. Your sure real glad two no.

Its very polished in its weigh, My checker tolled me sew

•Defensive ?• On top of steep slopes• Good views of surrounding land?• Invisible interiors ?

Or

Constructing a sense of place?Seeing and being seen?

•Contextualising the act of 

interpretation e.g. Video, 

diaries•Broadcasting the data, e.g. 

hypermedia•Storing multiple 

interpretations in parallel•Reactive site investigation