DART geophysics GeoScanRM15 Surveys

Earth Resistance geophysics data collected as part of the DART time-lapse study. Data was collected over a fieldwork season from June 2011 to September 2012. The surveys were conducted using a Geoscan RM15 datalogger with MPX15 Multiplexer set up for Twin-Probe surveys at four different probe spacings (0.25m, 0.50m, 0.75m and 1m). The survey was undertaken at a X and Y resolution of 0.5m over a 10m grid and recorded with a RM15 Geoscan Data-logger. At each measurement station the mobile probe separation is automatically increased at 0.25m intervals which can be roughly equated with an increased depth estimate of investigation.

Data and Resources

Additional Info

Field Value
Author Robert Fry
Maintainer Anthony Beck
instrument Geoscan RM15 Earth Resistance Meter
instrument.calibrationDetails Calibrated by Geoscan on purchase (http://www.geoscan-research.co.uk/)
instrument.geophysics.areaSurveyed 10m x 10m grid
instrument.geophysics.dataGridSize 10m x 10m
instrument.geophysics.directionOfFirstTravers HHCC = NW, HHQF = NE, DDPF = NW, DDCF =SE
instrument.geophysics.earthResistanceSurvey.electrodeConfiguration Twin probe
instrument.geophysics.earthResistanceSurvey.electrodeSpacing 0.25m, 0.5m, 0.75m, 1m
instrument.geophysics.earthResistanceSurvey.multipleConfigurations Geoscan MPX15
instrument.geophysics.methodOfCoverage Zigzag
instrument.geophysics.positionOfFirstTraverse HHCC = SE corner, HHQF = SW corner, DDPF = SE corner, DDCF = NW corner
instrument.geophysics.sampleInterval 0.5m
instrument.geophysics.surveyType Earth resistance, gridded area survey
instrument.geophysics.traverseSeparation 0.5m
instrument.headerMetadata No header information included on download
instrument.measurementDomainAndUnits Ohms
resource.abstract Earth Resistance geophysics data collected as part of the DART time-lapse study. Data was collected over a fieldwork season from June 2011 to September 2012. The surveys were conducted using a Geoscan RM15 datalogger with MPX15 Multiplexer set up for Twin-Probe surveys at four different probe spacings (0.25m, 0.50m, 0.75m and 1m). The survey was undertaken at a X and Y resolution of 0.5m over a 10m grid and recorded with a RM15 Geoscan Data-logger. At each measurement station the mobile probe separation is automatically increased at 0.25m intervals which can be roughly equated with an increased depth estimate of investigation.
resource.accessConstraints None
resource.bibliographicCitation @data{dart_geophysics_geoscanrm15, doi = {not allocated}, url = {http://dartportal.leeds.ac.uk/dataset/dart_geophysics_geoscanrm15}, author = {Robert Fry}, publisher = {The DART project, School of Computing, University of Leeds}, title = {DART geophysics GeoScanRM15 Surveys}, 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 Investigation. The survey is part of a monthly programme of data collection over 2011-2012. Resistance Meter used: Geoscan RM15: These instruments measure the electrical resistance of the earth, using a system of four electrodes (two current and two potential). Depending on the arrangement of these electrodes an exact measurement of a specific volume of earth may be acquired. This resistance value may then be used to calculate the earth resistivity. The most common arrangement is the Twin Probe configuration which involves two pairs of electrodes (one current and one potential): one pair of probes ('remote' probes) remain in a fixed position, whilst the other 'mobile' probes measure the resistance variations across a gird. The resistance is measured in ohms and, when calculated, resistivity is in ohm-metres. The resistance method as used for this area survey employs probe separations of 0.25m, 0.5m, 0.75m and 1m, which samples an approximate hemisphere between the mobile probes. Hence, a greater depth of investigation is theoretically possible with a wider probe spacing. The nature of the overburden and underlying geology will cause variations in this depth. 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-Serial cable and downloaded into Geoplot (Geoscan's in-house processing software). The surveys consist of 10m x 10m grids, and for this survey, measurements from the sensor/probes were logged at intervals of 0.5m along traverses spaced 0.5m apart. This gives 400 measurements per grid. Data are outputted as .CSV text files. Filenames are arranged first by the project (DART), then by instrument (GeoscanRM15), then by field (either DDPF, DDCF, HHCC, HHQF), then by date (YYYYMMDD), then by category (RAW or PRO), then by the mobile probe spacing (A=0.25m, B=0.5m, C=0.75m, D=1m). The RM15 resistance meter provides current ranges of 1mA to 0.1mA at an output voltage of 40V, giving a maximum logged resolution of 0.005 ohms. The operating frequency of 137Hz prevents the instrument to being affected by power line operating frequencies and harmonics. Further details and specifications of the instrument can be found and downloaded from the following link http://www.geoscan-research.co.uk/page22.html
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, Remote Sensing, Earth Resistance, Twin Probe, Multiplexed
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_geoscanrm15
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 Data is processed within Geoscan's Geoplot 3 software (http://www.geoscan-research.co.uk/page9.html) to a very basic level. The data is despiked to remove any potential errors in the data which are most likely related to bad probe contact with the ground, causing a spike in readings, unrelated to the measurement electrical resistance. No further processing is applied.
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 Earth resistance 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_geoscanrm15
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.