1. How I spent my summer vacation. By: Matthew Ludwig

2. GEM-2 and Geomagnetic Surveying at a Coalition Period Archeological Site Looking for “hidden treasures” in the GEM-2 and GM data sets collected at the LANL Archaeological Site #LA-135290 SAGE 2002 Matthew Ludwig Santa Fe, NM

3. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

4. The GEM-2

5. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

6. Step 1 Unprocessed GEM Data Low Frequency Real Component GEM-2 Data Processing

7. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

8. Step 2 Linear Trend Removal GEM-2 Data Processing

9. Step 3 5 Pass Smoothing GEM-2 Data Processing

10. Step 4 Expanding the Scale GEM-2 Data Processing

11. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

12. Low Frequency ~1000Hz In-Phase Quadrature GEM-2 Interpretation

13. Middle Frequency-5000Hz In-Phase Quadrature GEM-2 Interpretation

14. In-Phase Quadrature GEM-2 Interpretation High Frequency-15000Hz

15. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

16. Geomagnetics

17. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

18. Survey #1 6/28/02 N-S Northing (m) Easting (m) Field Strength (nT) STAKE 815

19. Survey #2 6/30/02 W-E Northing (m) Easting (m) Field Strength (nT) STAKE 2 40

20. W-E vs. N-S

21. Presentation Outline  GEM-2  The Raw Data  The Data & Processing  The Interpretation  GM  The Raw Data  The Data & Processing  The Interpretation  Comparisons & Conclusions

22. Step 0 – Raw Data (SD) Data Point (distance) Field Strength (nT) x 10,000

23. Step 0 – Raw Data (SD) Y=mx+b Data Point (distance) Field Strength (nT) x 10,000

24. Step 1 Removal of Trend (SD) Data Point (distance) Field Strength (nT) x 10,000

25. Step 2 – FFT to Frequency Domain Log Plot (FD) Frequencies Log Field Strength (nT) x 10,000 Nyquist Frequency +LOW- +High-

26. Step 3 – Log plot of the Results of Bandpass Filter in Frequency Domain Frequencies Log Field Strength (nT) x 10,000

27. Finally – Bandpass filtered data Data Point (distance) Field Strength (nT) x 10,000

28. Comparing Filtered Results Line 8-1Line 40-2

29. Presentation Outline  GEM-2  The Basics  The Data & Processing  The Interpretation  GM  The Basics  The Data & Processing  The Interpretation  Comparisons & Conclusions

30. GEM-2 (LF) vs Magnetics (NS)

31. STAKE MN

32. Conclusions Both data sets turned out to appear more meaningful after filtering Low Frequency GEM-2 and Magnetics Plots show obvious similarities Surface structure correlations are more apparent in the GM data It will be interesting to see the results of the excavation study