1. Ground-Based FMCW radar measurements: a summary of the NASA CLPX data H.P. Marshall Institute of Arctic and Alpine Research, Univ. of Colorado Gary Koh, Cold Regions Research and Engineering Lab, New Hampshire Rick Forster, Department of Geography, University of Utah

2. Br ief FMCW Theory I +=

3. Br ief FMCW Theory II Linear frequency chirp transmitted (T) Received signal (R) “mixed” with transmitted wave before signal acquisition Recorded signal contains the sum and difference frequencies from T + R Frequency differences from reflectors linearly related to the distance to target

4. Windowed FFT, zero-padded, normalized by DC-coupling, power from surface calibration

5. Filter instrumentation-related signals Locations where mean of signal > 5x mean deviation found Mean trace at these depths subtracted from scan

6. Depth Calibration Metal reflectors placed at known depths Accurate depth scale, will also be used to calculate attenuation

7. Michigan Ridge, North Park, Feb 21,2003

8. Berthud Pass, February 22, 2003

10. Relationship of FMCW signal manual measurements

11. Density profile vs radar

12. In-situ Dielectric Properties

13. In-situ Dielectric Properties II

14. LSOS Feb 19, 2002, C-Band: 2-6 GHz DRY SNOWPACK

15. LSOS Feb 19, 2002, X-Band: 8-12 GHz DRY SNOWPACK

16. LSOS Feb 19, 2002, Ku-Band: 14-18 GHz DRY SNOWPACK

17. LSOS March 26, 2002, C-Band: 2-6 GHz WET SNOWPACK

18. LSOS March 26, 2002, X-Band: 8-12 GHz WET SNOWPACK

19. LSOS March 26, 2002, Ku-Band: 14-18 GHz WET SNOWPACK

20. Effect of incidence angle

21. Effect of incidence angle II

22. Conclusions FMCW signal strongly related to in-situ dielectric measurements Resolution highest at Ku-Band, but little penetration if wet Incidence angle measurements indicate surface scattering dominates below ~15 deg and volume scattering above 30 Preliminary comparison with FMCW measurements at more narrow bandwidths encouraging

23. Acknowledgements NASA Earth System Science Fellowship CRREL Kelly Elder, Don Cline Nate Mullheren