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Microwave Remote Sensing of Snowpack

Northern Hydrometeorology Group, UNBC. Microwave Remote Sensing of Snowpack. Do-Hyuk “DK” Kang Postdoctoral Fellow Northern Hydrometeorology Group (NHG) Environmental Science and Engineering University of Northern BC February 5 th 2013. Discovery and Acceleration Fund. Outline.

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Microwave Remote Sensing of Snowpack

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  1. Northern Hydrometeorology Group, UNBC Microwave Remote Sensing of Snowpack Do-Hyuk “DK” Kang Postdoctoral Fellow Northern Hydrometeorology Group (NHG) Environmental Science and Engineering University of Northern BC February 5th 2013 Discovery and Acceleration Fund

  2. Outline • Fundamentals of remote sensing • Satellites and sensors • Application of remote sensing • Remote sensing of snow in the Cariboo Mountains of BC (Jinjun Tong) • Microwave Remote Sensing • Results (DK and Déry)

  3. Remote Sensing is a technology for sampling electromagnetic radiation to acquire and interpret non-immediate geospatial data from which to extract information about features, objects, and classes on the Earth's land surface, oceans, and atmosphere (and, where applicable, on the exteriors of other bodies in the solar system, or, in the broadest framework, celestial bodies such as stars and galaxies).

  4. Energy Source or Illumination (A) • Radiation and the Atmosphere (B) • Interaction with the Target (C) • Recording of Energy by the Sensor (D) • Transmission, Reception, and Processing (E) • Interpretation and Analysis (F) • Application (G)

  5. Electromagnetic Radiation

  6. Interactions with the Atmosphere Scattering Absorbing

  7. Those areas of the spectrum which are not severely influenced by atmospheric absorption and thus, are useful to remote sensors, are calledatmospheric windows

  8. Target Interactions • Absorption (A) occurs when radiation (energy) is absorbed into the target while transmission (T) occurs when radiation passes through a target. Reflection (R) occurs when radiation "bounces" off the target and is redirected.

  9. water and vegetation may reflect somewhat similarly in the visible wavelengths but are almost always separable in the infrared.

  10. Passive vs. Active Remote Sensing Passive Sensing Active Sensing

  11. Satellites and Sensors • In order for a sensor to collect and record energy reflected or emitted from a target or surface, it must reside on a stable platform removed from the target or surface being observed. Platforms for remote sensors may be situated on the ground, on an aircraft or balloon (or some other platform within the Earth's atmosphere), or on a spacecraft or satellite outside of the Earth's atmosphere. Although ground-based and aircraft platforms may be used, satellites provide a great deal of the remote sensing imagery commonly used today.

  12. Satellite Orbits Geostationary orbits Near-polar orbit Ascending vs Descending

  13. Weather Satellites/Sensors • TIROS-1(launched in 1960 by the United States) • GOES (Geostationary Operational Environmental Satellite) -GOES-1 (launched 1975), GOES-8 (launched 1994) • Advanced Very High Resolution Radiometer(NOAA AVHRR)(sun-synchronous, near-polar orbits) • FengYun-1, FengYun-2, FengYun-3, FengYun-4 (China) • GMS (Japan) • Meteosat (European)

  14. Land Observation Satellites/Sensors • Landsat (Landsat-1 was launched by NASA in 1972, near-polar, sun-synchronous orbits). -Return Beam Vidicon (RBV), MultiSpectral Scanner (MSS), Thematic Mapper (TM) • SPOT(SPOT-1 was launched by France in 1986, sun-synchronous, near-polar orbits) -Twin high resolution visible (HRV) • Multispectral Electro-optical Imaging Scanner(MEIS II) Compact Airborne Spectrographic Imager(CASI)(airborne sensors)(Canada) • Canadian RADARSAT I and II - (Active Microwave Remote Sensing)

  15. Data Reception, Transmission, and Processing In Canada, CCRS operates two ground receiving stations - one at Cantley, Québec (GSS), just outside of Ottawa, and another one at Prince Albert, Saskatchewan (PASS)

  16. Quiz

  17. The Quesnel River Basin (QRB) in the Cariboo Mountains • It is one of 13 main sub-basins in the Fraser River Basin, one of the world's most productive salmon river systems. • Snow plays a vital role in the energy and water budgets of these basins.

  18. Evaluation of MODIS data MODIS Ground Accuracy of different MODIS snow data

  19. Results Snow cover fraction (%) The spatially filtered snow cover fraction (SCF) for different elevation bands (top) and aspects with slopes > 15o (bottom), 2000-2007.

  20. The mean elevational dependence of snow cover fraction (SCF) for the months of February to July, 2000-2007.

  21. The annual snow cover duration (x3 days) in the QRB based on spatially filtered (SF) MODIS snow products, 2001-2007. Mean snow cover durations (SCD) for 10-m elevation bands from the MOD10A2 (+) & SF (□) products, 2001-2007. SCD (days) r = 0.96 d(SCD)/dz = 11.6 days (100 m)-1

  22. Scatter plot between average air temperature and SCF50% (top) and scatter plot between SCF50% & R50% during spring for the QRB, 2000-2007 (bottom).

  23. Quiz

  24. Snow Microwave Sensors • SMMR (scanning multichannel microwave radiometer) - It measured dual-polarized microwave radiances, at 6.63, 10.69, 18.0, 21.0, and 37.0 GHz, from the Earth's atmosphere and surface. • SSM/I (special sensor microwave/imager) -The instrument measures surface/atmospheric microwave brightness temperature (TBs) at 19.35, 22.235, 37.0 and 85.5 GHz. • AMSR-E ( Advanced Microwave Scanning Radiometer-EOS). -12 channels and 6 frequencies ranging from 6.9 to 89.0 GHz. H-pol. and V-pol.

  25. Energy Flux VS Intensity • Energy flux is defined by the energy flow with a given area [W/m2] • Intensity is defined by the energy flow per a given area, a given frequency, and a given solid angle [W/m2 Hz Steradian] – a physically imaginary term but important for the interpretation in Remote Sensing

  26. Fraser River  Snow Dominant Watershed

  27. 1 mm grids, Salminen et al. 2009

  28. Quiz

  29. Passive vs. Active Sensing

  30. Frolov and Marchert 1999, Hallikainen et al. 1986, TGRS

  31. Key Words Tb Brightness Temperature Real Permittivity Absorption Coeffi. Imaginary Permittivity Scattering Coeffi. Tb Ts pec LWC freq Matzler and Wiesmann 1999 Devonec and Barros 2002

  32. Kang et al. 2012 Accepted in IEEE Willis et al. 2012 RS and Env Schanda and Matzler 1981

  33. Derksen et al. 2012 RS env

  34. Derksen et al. 2005, Chang et al. 1987

  35. Time series (left) and scatter plots (right) of the observed & retrieved SWE from algorithms using different AMSR-E channel combinations at Yanks Peak East from 2003-2005.

  36. Conclusions • Use Remote Sensing to cover global scale monitoring of snowpack • Visible and Microwave Remote Sensing of Snowpack • Reflectance and Microwave Radiometry • Antenna Response Model VS Radiometry observation • Wave signatures VS Snow physical properties

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