DART geophysics CMDMiniExplorer

Electromagnetic Induction geophysics data collected as part of the DART time-lapse study. Data was collected over a fieldwork season from April 2012 to September 2012. The surveys were conducted using a GF Instruments Electromagnetic Induction CMD MiniExlorer which collected both In-phase and Quadrature data in Horizontal Coplanar (HCP) and Vertical Coplanar (VCP) configurations, at 5 depth levels. The survey was undertaken at a traverse seperation of 0.5m and a timed trigger rate of 0.2 seconds over a 10m survey grid.

Data and Resources

Additional Info

Field Value
Author Robert Fry
Maintainer Anthony Beck
instrument GF Instruments CMD MiniExplorer
instrument.calibrationDetails Instrument calibrated by manufacturer (GF Instruments) in 2012
instrument.geophysics.areaSurveyed 10m x 10m
instrument.geophysics.dataGridSize 10m x 10m
instrument.geophysics.directionOfFirstTravers HHCC = NW, HHQF = NE, DDPF = NW, DDCF = SE
instrument.geophysics.lowFrequencyElectromagneticSurvey.coilConfiguration Horizontal Coplanar (HCP) and Vertical Coplanar (VCP) configurations
instrument.geophysics.lowFrequencyElectromagneticSurvey.depthComponent Multi-depth effective range of 0.5m, 0.25m, 0.9m, 1m and 1.8m
instrument.geophysics.lowFrequencyElectromagneticSurvey.recordedComponent In-phase (ppt) and Quadrature (converted into conductivity mS/m)
instrument.geophysics.methodOfCoverage Zigzag
instrument.geophysics.positionOfFirstTraverse HHCC = SE corner, HHQF = SW corner, DDPF = SE corner, DDCF = NW corner
instrument.geophysics.sampleInterval 0.2 seconds
instrument.geophysics.surveyType Gridded area survey
instrument.geophysics.traverseSeparation 0.5m
instrument.headerMetadata GridX, Grid Y, Inphase_ppt, (or) Conductivity_mS/m
instrument.measurementDomainAndUnits In-Phase (ppt) and Quadrature (mS/m)
resource.abstract Electromagnetic Induction geophysics data collected as part of the DART time-lapse study. Data was collected over a fieldwork season from April 2012 to September 2012. The surveys were conducted using a GF Instruments Electromagnetic Induction CMD MiniExlorer which collected both In-phase and Quadrature data in Horizontal Coplanar (HCP) and Vertical Coplanar (VCP) configurations, at 5 depth levels. The survey was undertaken at a traverse seperation of 0.5m and a timed trigger rate of 0.2 seconds over a 10m survey grid.
resource.accessConstraints None
resource.bibliographicCitation @data{dart_geophysics_cmdminiexplorer, doi = {not allocated}, url = {http://dartportal.leeds.ac.uk/dataset/dart_geophysics_cmdminiexplorer}, author = {Robert Fry}, publisher = {The DART project, School of Computing, University of Leeds}, title = {DART geophysics CMDMiniExplorer}, year = {2013}, note = {DART is a Science and Heritage project funded by AHRC and EPSRC. Further DART data and details can be found at http://dartportal.leeds.ac.uk}}
resource.completeness Complete
resource.consistency Consistent data structure, attribution and relationships.
resource.creation.endDateTime 2012
resource.creation.startDateTime 2011
resource.creation.status Complete
resource.creator.email r.j.fry@student.bradford.ac.uk
resource.creator.name Robert Fry
resource.creator.orcID http://orcid.org/0000-0002-9711-1131
resource.custodian.email a.r.beck@leeds.ac.uk
resource.custodian.name Anthony Beck
resource.custodian.orcID http://orcid.org/0000-0002-2991-811X
resource.description Electromagnetic Induction (EMI) data collected from geophysical survey at the DART geophysical survey areas (Cherry Copse and Quarry Field at Cirencester - Diddington Clay and Diddington Pasture at Diddington) over the DART fieldwork season from April 2012 to September 2012. The survey was conducted using a GF Instruments CMD MiniExplorer at both Horizontal Coplanar (HCP) and Vertical Coplanar (VCP) configurations. Surveys at each of these configurations yields data from 3 different depths, based on manufacturer sensitivity plots. For the HCP configuration depths of 0.5m, 1m and 1.8m are possible. At a VCP configuration, depths of 0.25m, 0.5m and 0.9m are possible. The survey was undertaken using a traverse interval of 0.5m over a 10m grid. Measurement intervals were controlled under a timed collection system every 0.2 seconds. Markers were logged every 1m along the traverse to ensure accuracy of measurements. The survey is part of a monthly collection programme of data collection over 2011-2012. EMI Meter: GF Instruments CMD Mini Explorer: These instruments measure the in-phase and quadrature signal produced by induction of an electromagnetic field into the earth. The in-phase and quadrature response can be equated to apparent magnetic susceptibility and apparent conductivity of the earth. This can therefore be a useful technique in discriminating both magnetic and resistivity values in a single survey. The application of this instrument for archaeological applications is presented in: Bonsall, J., Fry, R., Gaffney, C., Armit, I., Beck, A., Gaffney, V. Forthcoming (2013). Assessment of Multi-Depth Prospection Capabilities using a new Low Frequency Electromagnetic Device. Archaeological Prospection. Further information from the manufacturer on the instrument can be found at http://www.gfinstruments.cz/index.php?menu=gi&smenu=iem&cont=cmd_&ear=ov All of the data are stored on an integrated data logger for subsequent post-processing and analysis. The instrument is connected to a computer via a USB cable and downloaded as text files. The surveys consist of 10m x 10m grids, and for this survey, measurements from the sensor/probes were logged at timed intervals of 0.2 seconds along traverses spaced 0.5m apart. Filenames are arranged first by project (DART), then by instrument (CMDMiniExplorer), then by field (one of HHCC, HHQF, DDPF, DDCF), then by date (YYYYMMDD), then by stage (RAW or PRO), then by sensor configuration (HCP or VCP), then by type of data collected (I = In-phase, Q = Quadrature data), then by depth level (A - C from shallowest to deepest levels - depths dependant on HCP or VCP configuration). Electromagnetic Induction data, X,Y,M values (M values indicating measurements of either In-phase (ppt) or quadrature response (mS/m) RAW = unprocessed (straight from sensor data).
resource.distribution.technique Download only
resource.edition 1
resource.fileFormat .csv, .zip
resource.funder Science and Heritage Programme, Arts and Humanities Research Council, Engineering and Physical Sciences Research Council
resource.instructionalMethod None - this is a collection
resource.keywords Geophysics, Archaeology, Monitoring, EMI, Quadtrature, In phase, Remote Sensing, Mini Explorer
resource.language eng
resource.license odc-by
resource.license.typeURL http://opendatacommons.org/licenses/by/
resource.lineage None: this is raw data
resource.localURI http://dartportal.leeds.ac.uk/storage/f/dart_geophysics_cmdminiexplorer
resource.metadata.creator.email r.j.fry@student.bradford.ac.uk
resource.metadata.creator.name Robert Fry
resource.metadata.creator.orcID http://orcid.org/0000-0002-9711-1131
resource.metadata.language eng
resource.processingStage Complete
resource.processingSteps The EMI data collected was first separated into datasets relating to depth, and then interpolated via a natural neighbour transformation in Golden Software's Surfer program where the data could be sampled at 0.5m x 0.5m intervals, matching the earth resistance resolution. From this, the data was imported into Geoscan Geoplot 3 software for minimal processing. Data were de-staggered (de-stepped) as necessary and exported as a .CSV file.
resource.publisher School of Computing, University of Leeds
resource.purpose multi-temporal heritage detection
resource.relatedResources DartProjectOverview
resource.repositoryName http://dartportal.leeds.ac.uk/
resource.reuseConstraints No conditions apply for reuse (remix it, publish it, share it, commercialise it, sell it etc.) except attribution (see resource.bibliographicCitation)
resource.reusePotential archaeology, environment, heritage, soil science, farming, ecology, geography, earth science
resource.samplingStrategy Electromagnetic Induction survey across a known archaeologcal feature (a ditch) was undertaken across a 10m x 10m survey grid. Survey data is collected once a month over the 15 month survey peroid at a spatial resolution of 0.5m.
resource.topic geoscientificInformation, environment, heritage, farming, climatology/Meteorology/Atmosphere, imageryBaseMapsEarthCover, society, structure
resource.type Dataset collection
resource.type.specific Geophysics
resource.updateFrequency not planned
spatial { "type": "Polygon", "coordinates": [ [ [-1.907587, 52.280552],[-0.246205, 52.280552], [-0.246205, 51.703178], [-1.907587, 51.703178], [-1.907587, 52.280552] ] ] }
spatial-text United Kingdom
spatial.boundingBox.OSGB36.east 519741
spatial.boundingBox.OSGB36.north 266160
spatial.boundingBox.OSGB36.referenceSystem OSGB36
spatial.boundingBox.OSGB36.south 200497
spatial.boundingBox.OSGB36.west 406483
spatial.boundingBox.WGS84.eastLongitude -0.246205
spatial.boundingBox.WGS84.northLatitude 52.280552
spatial.boundingBox.WGS84.referenceSystem WGS84
spatial.boundingBox.WGS84.southLatitude 51.703178
spatial.boundingBox.WGS84.westLongitude -1.907587
spatial.defaultReferenceSystem OSGB36
spatial.driftGeology DDCF: http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=TILMP, DDPF: http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=T1T2, HHCC: Clay: no superficial drift geology, HHQF: no superficial drift geology
spatial.landuse Permanent pasture: DDPF, Arable: DDCF, HHCF, HHQF
spatial.ordnanceSurveyPlaceName Harnhill (http://data.ordnancesurvey.co.uk/id/50kGazetteer/109734) and Diddington (http://data.ordnancesurvey.co.uk/id/50kGazetteer/72767)
spatial.polygon.OSGB36 { "type": "Polygon", "coordinates": [ [ [406483, 266160],[519741, 266160], [519741, 200497], [406483, 200497], [406483, 266160] ] ] }
spatial.polygon.WGS84 { "type": "Polygon", "coordinates": [ [ [-1.907587, 52.280552],[-0.246205, 52.280552], [-0.246205, 51.703178], [-1.907587, 51.703178], [-1.907587, 52.280552] ] ] }
spatial.solidGeology DDCF and DDPF: http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=OXC, HHCC: http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=CB, HHQF: http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=SI
temporal.rangeDescribedByDataDateTime.end 2011
temporal.rangeDescribedByDataDateTime.start 2012
temporal.resource.availableDate 2013-07-15
title.alternative dart_geophysics_cmdminiexplorer
title.pattern Where appropriate each resource has been named with the following pattern: DART_<3 character sensor/collection name>_<spatial location>_<StartDateTime YYYYMMDD with optional HHMM>_<endDateTime YYYYMMDD with optional HHMM>_<stage PRO or RAW to refer to processed or raw data>_<other stuff>.<suffix>. Hence, the file DART_T3P_DDCF_20110823_20130106_PRO.csv refers to DART data collected using the T3P Imko soil moisture probes at Diddington Clay Field between 23rd August 2011 and 6th January 2013 which has been processed and is available in a comma separated text format.