Land Magnetometer Training Course

• Magnetic Theory ½ day• Hardware (G858/AP) ¼ day• Software (MagMap / MagPick) ¼ day• Hardware setup (858 and GPS) ½ day• Survey ½ day• Processing ½ day• Review ½ day

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Geometrics, Inc.Premier Manufacturer of Land Magnetometers

GEOMETRICS MAGNETOMETERS-tools for exploration

Applications:• Map Geology for Mining, Oil/Gas Exploration

• Environmental Survey for Tanks, Barrels

• Locate Utilities, Pipelines

• Military Uses, UXO-EOD, De-mining

• Archaeology

• Used in Land-Marine-Airborne Surveys

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GEOMETRICS: a 30-year history of building magnetometers

• 1969: G-801 & G-803 marine and airborne proton magnetometers• 1971: G-806 land and marine proton magnetometer• 1973: G-816 portable proton magnetometer• 1977: G-826 portable digital magnetometer• 1981: G-856 portable memory magnetometer• 1983: G-811 marine magnetometer• 1991: G-822L military magnetometer• 1992: G-825 military diver-held magnetometer• 1992: G-822A airborne cesium magnetometer• 1995: G-858 portable cesium magnetometer• 1996: G-880 marine cesium magnetometer• 1997: G-823A airborne cesium magnetometer with counter• 1998: G-881 marine light-weight cesium magnetometer• 2003: G-882 marine cesium magnetometer • 2005: G-859 cesium mining magnetometer• 2009: UAV, AUV testing• 2013: G-860 land cesium magnetometer• 2014: G-862RBS cesium base station

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Magnetometer Configurations

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UXO Magnetometer Configurations

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Sensor Noise – Spin analysis

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Sensor Noise – Tumble Analysis

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Sensor Noise – Various Motions

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Earth’s Magnetic Field Diagram

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Earth’s Magnetic Field – Solar effectsEarth’s Magnetic Field: detection of magnetic anomalies

• Earth’s dipole magnetic field is perturbed by relatively localized contrasts in magnetization.

• Magnetization contrasts are caused by ferrous debris, vessels, pipelines, communication cables, magnetic minerals (predominantly magnetite).

• With magnetometers, one can measure the total field to detect the magnetic anomalies associated with contrasts.

• Earth’s dipole (N-S) magnetic field is produced by internal iron core dynamo effect. Charged particles from the sun cause a bow shock wave in the magnetosphere which leads to Diurnal Variations

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Earth’s Total Magnetic Field

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Earth’s Magnetic Inclination

Diurnal Variations

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Optional Diurnal / Base Station Monitor

• Use either G-858 or G-856 Magnetometers

• Monitor Magnetic Diurnal Variations

• Magnetometer in fixed location

• Synchronized clocks

• 1-30 second sample rate

• Use for correction of survey data

• Produce more accurate magnetic maps

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Sensor Dead Zone Diagram

Sensor Diagrams - CSAZ

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Sensor Dead Zone – 0 Degree Tilt

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Sensor Dead Zone – 45 Degree Tilt

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Results of Survey profile width

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Anomaly patterns as a result of Inclination

Anomaly width versus depth

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Depth estimate

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Nomogram

Anomalies of common objects

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Vertical Gradient Applications

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Wearing the G-858

Gradiometer Transverse Layout

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WITH agGPS-114/132 STEERINGG-858 CESIUM GRADIOMETER

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Standard Survey Acquisition

Swath Spacing

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GPS Differential Corrections

• Coast Guard Beacon

• OmniStar (On shore only without special license)

• Racal (On shore only without special license)

• RTCM

• RTK

• Known Antenna and Satellite positions and frequencies

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Data Processing Software – Magmap 2000

Software capabilities

• Import G-858 magnetometer (1 or 2 sensors)

• Convert GPS Lat / Long to UTM XY coordinates

• Correct for GPS offset from Magnetometer sensor

• Perform Spike filtering

• Import G-858 or G-856 base station data

• Merge Base Station data with survey Data

• Export in Surfer or Geosoft format

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MagMap 2000 Destripping tool

Surfer Software Capabilities

• Windows based program for professional displays

• Grid and contour G-858 data

• Display sample locations on contour map

• Various types of displays for interpretation

• Export Windows Metafile and ASCII grid files for MagAID

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Surfer Displays – Ft. Ross

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Stanford Base Map

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Surfer 3 dimensional display

Stanford shaded relief

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Stanford Magnetic Contour Map

MagPick – Filtering theory

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RAW DATA

MANUAL SMOOTHING

3 POINT RUNNING AVERAGE