Land Magnetometer Training Course Magnetic Theory Hardware G

Land Magnetometer Training Course • Magnetic Theory • Hardware (G 858/AP) • Software (Mag. Map / Mag. Pick) • Hardware setup (858 and GPS) • Survey • Processing • Review ½ day ¼ day ½ day

Geometrics, Inc. Premier Manufacturer of Land Magnetometers Slide 2

GEOMETRICS MAGNETOMETERStools 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 Slide 3

GEOMETRICS: a 30 -year history of building magnetometers • • • • • Slide 4 1969: G-801 & G-803 marine and airborne proton magnetometers 1971: G-806 land 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-822 L military magnetometer 1992: G-825 military diver-held magnetometer 1992: G-822 A airborne cesium magnetometer 1995: G-858 portable cesium magnetometer 1996: G-880 marine cesium magnetometer 1997: G-823 A 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-862 RBS cesium base station

Magnetometer Configurations Slide 5

UXO Magnetometer Configurations Slide 6

Sensor Noise – Spin analysis Slide 7

Sensor Noise – Tumble Analysis Slide 8

Sensor Noise – Various Motions Slide 9

Earth’s Magnetic Field Diagram Slide 10

Earth’s Magnetic Field: detection of magnetic anomalies Earth’s Magnetic Field – Solar effects • 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 • 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. • • Slide 11

Earth’s Total Magnetic Field Slide 12

Earth’s Magnetic Inclination Slide 13

Diurnal Variations Slide 14

Optional Diurnal / Base Station Monitor • • Slide 15 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 Slide 18

Sensor Diagrams - CSAZ Slide 19

Sensor Dead Zone – 0 Degree Tilt Slide 20

Sensor Dead Zone – 45 Degree Tilt Slide 21

Results of Survey profile width Slide 22

Anomaly patterns as a result of Inclination Slide 23

Anomaly width versus depth Slide 24

Depth estimate Slide 25

Nomogram Slide 26

Anomalies of common objects Slide 27

Vertical Gradient Applications Slide 28

Wearing the G-858 Slide 29

Gradiometer Transverse Layout G-858 CESIUM GRADIOMETER Slide 30 WITH ag. GPS-114/132 STEERING

Standard Survey Acquisition Swath Spacing Slide 31

GPS Differential Corrections • • • Coast Guard Beacon Omni. Star (On shore only without special license) Racal (On shore only without special license) RTCM RTK Known Antenna and Satellite positions and frequencies Slide 32

Data Processing Software – Magmap 2000 Slide 33

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 Slide 34

Mag. Map 2000 Destripping tool Slide 35

Surfer Software Capabilities • • • Slide 36 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 Mag. AID

Surfer Displays – Ft. Ross Slide 37

Stanford Base Map Slide 38

Surfer 3 dimensional display Slide 39

Stanford shaded relief Slide 40

Stanford Magnetic Contour Map Slide 41

Mag. Pick – Filtering theory RAW DATA MANUAL SMOOTHING 3 POINT RUNNING AVERAGE Slide 42