MakingTemporalSearchMoreCentralinaSpatialDataInfrastructure

BenjaminLewis,PaoloCorti

20172nd InternationalSymposiumonSpatiotemporalComputing

HarvardUniversity

Thesis

• Timeisanunderutilizeddimensionforimprovingsearchingeosystems.

• Straightforwardmethodsexistwhichcanbetransformativeforresearch.

(BetteruseoftheTemporalisjustoneofseveralwaysinwhichSDIscanbemodernized.)

GeoPlatform SearchUI

GeoNode SearchUI

Systemswehavebeenworkingon

1. WorldMap – Generalpurposepublicmappingplatform.Inexistencesince2012.

2. TheBillionObjectPlatform(BOP)– Prototypetolowerbarrierstoaccesstobigstreamingdatasets.Recentlyreleased.

Differentsystems,commonneedtoimprovesearch

1. WorldMap (ManyDatasets)- Thousandsofdatalayerswithimperfectmetadata.

2. BOP(OneBigDataset)- Abilliongeoreferenced,timestampedtweets.

Listofenhancementstobediscussed

• TimeMinerforunstructuredtextmetadata• SortingBC/ADdates• Timebarfordaterangedefinition• Logarithmictimebarincrements• Dynamictemporalhistogram• Abilitytozoomontemporalhistogram

PythonTimeMinertoenrichmetadata

• Metadataformaplayersisofteninconsistentfortimereferencing.

• Standardwaysofdescribingdate/timesuchasISO8601arerarelyused.

• Temporalcharacteristicsmentionedasunstructuredtextinthetitle,abstract,andelsewhere.

InitialsimpleTimeMiner Logic

1. Lookfordateinthedaterangesectionofthemetadataandchoosetheearlierdate.(Date:fromMetadata)

2. Ifthereisno#1above,lookfor4digitnumbersintitlefirst,thenabstract,whicharelessthanorequalto2017(presentyear)(Date:Detected)

3. IfthereISadatein#2above,checktoseewhetherthereisaCEorADorBCEorBCafteritandapplymathaccordingly(Date:Detected)

4. IfthereISNO#2above,lookfor1,2,or3digitnumberswithassociatedCE,AD,BCE,BC,andapplymathaccordingly(Date:Detected)

Anothertechnique:HistoricPeriodsExample:ChineseDynasties

• Xia, Hsia ca.2100-1600BCE• Shang ca.1600-1050BCE• Zhou,Chou ca.1046-256BCE• Qin,Ch'in 221-206BCE• Han 206BCE-220CE• Sui 581-618CE• Tang,T'ang 618-906• Song,Sung 960-1279• Yuan 1279-1368• Ming 1368-1644• Qing,Ch'ing 1644-1912Source:http://afe.easia.columbia.edu/timelines/china_timeline.htm

WorldMap SearchDemo

• animation

• anim

TemporalHistogram

Conclusion• Mostspatialdatadescribeseventsintime thoughoftennotexplicitly.

• Whendatadoeshaveatimecomponentitisoftennoteasilyaccessed.

• Anopportunityexiststoincreasethevalueofexistingdataby:1. Makinglatenttemporalinformationexplicitusing

enrichmenttechniques2. ImplementingUI/backendenhancementsonexisting

systems3. Increaseresearchonspace/timedataexploration

MoreinformationWorldMap /HHypermap• Information

http://gis.harvard.edu/publications/implementing-open-source-spatiotemporal-search-platform-spatial-data-infrastructures

• Sourcecodehttps://github.com/cga-harvard/HHypermap

BOP• Informationhttp://gis.harvard.edu/services/project-

consultation/project-resume/billion-object-platform-bop• Sourcecodehttps://github.com/cga-harvard/hhypermap-

bop

Thankyou

http://worldmap.harvard.edu

BenjaminLewisblewis@cga.harvard.edu

PaoloCortipcorti@fas.harvard.edu