w3g conference: geodata at the british museum

Geodata use at the British Museum

Enhancing archaeological recordsDaniel Pett

dpett@britishmuseum.org

Portable Antiquities Scheme

• 17,900 contributors of data

• 640,000 objects recorded• 400,000 geo-referenced

find spots• All available under CC

NC-BY-SA• Driving archaeological

knowledge of rural areas• Funded by DCMS

• Employ 56 people• Deal with public

discovery of archaeology

• Started in 1997• Costs £1.4mill per

annum• IT budget c.£5000

Recording: one chance

Our staff generally have one chance to record Dissemination online is swift, cheap, easy There is no other archaeological database of this size It is underused for research at present The data it contains can tell a thousand stories of our shared heritage

Objects by year

449,359 objects online @ 23:20 26/2/10 – 400K in 7 years!

Most data is sourced from metal-detecting

GPS co-ordinates if possible

All objects recorded online

The Staffordshire Hoard

Frome (Somerset) Hoard

Crosby Garrett (Lancashire) Helmet

A more normal discovery

Objects referencing place:The Staffordshire Moorlands trulla

This is a list of four forts located at the western end of Hadrian's Wall; Bowness (MAIS), Drumburgh (COGGABATA), Stanwix (UXELODUNUM) and Castlesteads (CAMMOGLANNA). it incorporates the name of an individual, AELIUS DRACO and a further place-name, RIGOREVALI.

http://www.finds.org.uk/database/artefacts/record/id/49791

Have you noticed a pattern?

Big discoveries named after place…Place => sense of identity

Why is the spatial data so important?

Without provenance: A museum cannot acquire an object Is it looted? Did the landowner give permission? Context has been lost, we don’t know the significance of the location of discovery.

"X" never, ever marks the spot.

Indiana Jones: Last Crusade

All objects we have recorded

• 1997 – 2010• Topographical features drive

discovery• Landowners and regulations

can prevent discovery• Biases present in data

collection eg. Staff illness, lack of car etc etc

Staff based here

Here be mountains

Using YQL

• Reverse geocode for WOEID for each findspot against flickr.places

• Get flickr shapefile if exists for WOEID• Obtain a co-ordinate for findspots where only place

is known (lower weight for academic use though).• Obtain elevation via the geonames api (for

viewshed analysis – surprisingly good!)• Find objects within bounding boxes• Query for archaeology images on flickr

Problems

• Hit rate limit quickly – now using Oauth calls to Yahoo apis

• Had to filter out places eg Copper Alloy, Tamil Nadu was constantly pulled out with Placemaker

• Took time to process 400,000 records for geodata

Display problems

• Public users can only see find spots at a resolution of 1km sq or 4 figure NGR

• Some find spots have to be hidden from public view completely – we give a place a pseudonym

• Maps make our finders and landowners jumpy• Zoom level had to be reduced for public users• WOEID can give away find location

Enhanced geo data via flickr shapefiles & Yahoo! geoplanet

This object only has a known place of discovery

So Yahoo! does legwork and produces geodata

Integration of old OS Maps

Layer provided by National Library of Scotland

Water Newton (Cambs) rally

Roman town of Durobrivae

Re-use of OS and EH point data

Both of these datasets came as CSV, now converted from grid refs to Lat/Lng and WOEID (and also elevation for centre point) if anyone wants them.

Data export

• All searches can be turned into KML/JSON/CSV/XML (however point data degraded to 1km square unless higher level user)

• Can be easily imported into Google maps for instance

• One example is a search for objects by Parliamentary constituency (powered by YQL on theyworkforyou and Haversine formula)

Simple YQL query: select * from twfy.getGeometry where name=‘Stratford-on-Avon’;

Powered by theyworkforyou api

<results> <twfy> <max_e>436973.6</max_e> <centre_lat>52.168328098</centre_lat> <area>670735121.325</area> <max_n>274456.4</max_n> <min_lat>51.9553938864</min_lat> <max_lat>52.3680842693</max_lat> <min_n>228616</min_n> <max_lon>-1.46139563588</max_lon> <centre_lon>-1.71287824875</centre_lon> <centre_n>252253.483284</centre_n> <parts>1</parts> <min_e>402695.3</min_e> <centre_e>419756.726723</centre_e> <min_lon>-1.96200666642</min_lon> <name>Stratford-on-Avon</name> </twfy> </results>

Objects in David Cameron’s constituency

What archaeologists would like: A database of places – ancient & modern?

• Ancient place names– Dates in use– Co-ordinates at that time– Affiliation (political)– Example database – Pleiades, NYU

http://pleiades.stoa.org/• Modern place names

The end.Visit our website : www.finds.org.uk

Contact me: dpett@britishmuseum.org

Twitter: @portableant