1. CLPX Workshop May 28-29, 2003 Boulder, Colorado Ground-based Radar Measurements of LSOS Snowpack Gilles CASTRES SAINT-MARTIN Kamal SARABANDI Radiation Laboratory University of Michigan

2. CLPX Workshop May 28-29, 2003 Boulder, Colorado 1.Motivations 2.Experiments 3.Results Outline

3. CLPX Workshop May 28-29, 2003 Boulder, Colorado 1.Radar Remote Sensing of snowpack parameters in a global scale Snow depth Snow density Snow wetness 2.Application of fully-polarimetric L- and Ku-band radars L-band to monitor sub-surface conditions Ku-band to monitor snow volume and sub-surface conditions 1. Motivations Snow-water equivalent

4. CLPX Workshop May 28-29, 2003 Boulder, Colorado 2. Experiments Chose a site at the FEF to study the dynamics of the target: only snowpack parameters are expected to change. Site specifications: ~200 sq meter-open snowpack Snow Conditions: dry during IOP3, wet and melting during IOP4 (limited) Ground Conditions: - Rough surface

5. CLPX Workshop May 28-29, 2003 Boulder, Colorado 2. Experiments Radar specifications: –L-band polarimetric scatterometer Center Frequency: 1.25 GHz Bandwidth: 300 MHz –Ku-band polarimetric scatterometer Center Frequency: 15.50 GHz Bandwidth: 500 MHz –3 incidence angles: 20, 35 and 50 degrees –4 linear polarizations: VV, VH, HV, HH

6. CLPX Workshop May 28-29, 2003 Boulder, Colorado

7. Sphere Meas.Snow Meas.Background Meas. Coherent subtraction Calibration (STCT) Post-processingFinal product Data Collection and Processing

8. CLPX Workshop May 28-29, 2003 Boulder, Colorado Calibration of the Ku-band Radar: 14’’ sphere time-domain response Sphere response Antenna aperture

9. CLPX Workshop May 28-29, 2003 Boulder, Colorado IOP3 IOP4 Correlation between the two co-pol backscattering coefficients 3. Results

10. CLPX Workshop May 28-29, 2003 Boulder, Colorado

12. Incidence angleAverage (in dB) Average (in dB) Standard Deviation (dB) Standard Deviation (dB) Ku-band 20 degrees -9.73-9.69 -17.87 -18.50 35 degrees -9.87-9.99-16.88-20.43 50 degrees -10.76-10.51-19.13-20.11 L-band 20 degrees -9.09-10.33-15.86-17.31 35 degrees -17.36-17.27-26.01-22.97 50 degrees -23.24-24.01-31.23-32.08 IOP3 (Feb 19 th -Feb 26 th )

13. CLPX Workshop May 28-29, 2003 Boulder, Colorado

15. Incidence angleAverage (in dB) Average (in dB) Standard Deviation (dB) Standard Deviation (dB) Ku-band 20 degrees -8.86-10.21-12.30-13.93 35 degrees -8.22-9.32-9.53-10.55 50 degrees -8.92-9.90-8.81-10.03 L-band 20 degrees -7.16-7.66-14.08-12.34 35 degrees -12.96-11.51-22.10-18.48 50 degrees -14.35-15.76-14.74-21.03 IOP4 (March 25 th -March 30 th )

16. CLPX Workshop May 28-29, 2003 Boulder, Colorado Correlation of the two co-pol backscattering coefficients

17. CLPX Workshop May 28-29, 2003 Boulder, Colorado

19. 94 fully polarimetric L- and Ku-band radar backscatter measurements of snow from 20 to 50 degrees (IOP3 & IOP4) High quality data, already calibrated Consistent results, with good accuracy In process of writing a report Conclusion