Page 5 - Marine Magnetometer Processing
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Contents 1. 2. 3. 4. 5. 6. 7. Introduction to Magnetometer Processing ...................................................................................... 6 Definition of Technical Terms........................................................................................................7 Basic Operation............................................................................................................................... 8 Anomalies and Targets.................................................................................................................. 10 Instruments, Signals and Noise.....................................................................................................14 Update Rate and Sample Interval......................................................................................................14 Noise ................................................................................................................................................. 15 Practical Data Collection .................................................................................................................. 18 Basic Processing ........................................................................................................................... 19 Introduction....................................................................................................................................... 19 Calculating Mass............................................................................................................................... 19 Survey Strategies .............................................................................................................................. 22 Identifying Anomalies and Targets................................................................................................... 23 Using a chart ..................................................................................................................................... 24 Further Processing ........................................................................................................................ 27 Introduction....................................................................................................................................... 27 Dealing with Spikes and Dropout ..................................................................................................... 27 Towfish Turns...................................................................................................................................27 Other Contamination.........................................................................................................................28 Dealing with the Effects of Geology................................................................................................. 28 Dealing with Diurnal Variation ........................................................................................................ 29 Levelling ........................................................................................................................................... 29 Wave Noise.......................................................................................................................................30 Calculating the Minimum Detectable Target....................................................................................31 Cables and Pipes ............................................................................................................................... 35 Reporting and Archiving............................................................................................................... 36 Introduction....................................................................................................................................... 36 Target List.........................................................................................................................................36 Metadata............................................................................................................................................ 37 Charts ................................................................................................................................................ 38 Coverage Plot....................................................................................................................................38 Minimum Detectable Target Plot...................................................................................................... 38 Contour Plots and Surfaces...............................................................................................................38 Archiving .......................................................................................................................................... 41 Bibliography ................................................................................................................................. 42 8. 9. Marine Magnetometer Processing \[4\] © 3H Consulting Ltd
