Radar Remote Sensing of Snowpack
Event details
| Date | 10.02.2014 |
| Hour | 11:00 |
| Speaker | Chung-Chi Lin, European Space Agency |
| Location | |
| Category | Conferences - Seminars |
Snow-Water-Equivalent (SWE) of snowpack is a critical parameter for the quantitative characterisation of land hydrological cycle, but is not retrieved by existing satellite remote sensing techniques which only provide information on snow cover extent. Existing knowledge of SWE comes from passive microwave radiometers, but these measurements are challenging to interpret, are very limited in their spatial resolution ( a few tens of kilometres) and do not allow retrieval over deep snowpack. A satellite synthetic aperture radar (SAR) mission could potentially deliver global coverage of snow-covered regions at an unprecedented high spatial resolution if operated at frequencies which are sensitive to snowpack.
A precise knowledge of the radar signature of snowpack is a pre-requisite towards quantitative retrieval of their physical parameters using SAR imagery from space. In view of the limited availability in the literature of radar scattering information of snowpack at X-band and above, the European Space Agency (ESA) has initiated experiments using a mast-mounted scatterometer. The objective of the measurements is to establish accurate data of snowpack scattering from X- to Ku-band together with relevant snowpack and meteorological parameters, continuously over complete snow seasons with a high temporal resolution.
ESAs SnowScat instrument is a real aperture scatterometer which was developed by Gamma Remote Sensing AG. It operates in a continuous wave mode, covers a frequency range of 9.15 (X-band) to 17.9 GHz (Ku-band) in a user-defined frequency-step and have a polarimetric capability. The measurement campaigns were started first in Feb. 2009 at Weissfluhjoch, Davos, Switzerland, as an initial test of the instrument. Physical characterisations of the snowpack as well as meteorological instrumentation provide detailed in-situ data for the interpretation of the SnowScat data. SnowScat was then moved to Sodankylä in Finland, a site of the Finnish Meteorological Institute in Lapland. In addition to the in-situ snowpack characterisations and meteorological observations, continuous passive microwave observations and direct measurements of the snow water equivalent using a Gamma Wave Instrument were also performed. During the 2012-2013 winter period, a vertical time-domain snow profiling experiment was carried out in addition for resolving the scattering contributions from the snow layers of different physical properties.
The SnowScat data set represents one of the most complete, detailed and accurate active microwave observation time-series of specific snowpacks at a local scale. This paper summarises the result of the SnowScat observations and their preliminary analysis against the in-situ snowpack data. The campaign data show that snowpack is a highly variable radar target at the SnowScat frequencies, showing strong dependency on continuous snow metamorphism of its microscopic structure which are further affected by meteorological events and their inter-annual variability. There appears to be no simple one-to-one relationship between the scattering radar cross-section and the snow depth, or its snow water equivalent.
LEMA (Laboratory of Electromagnetics and Acoustics)
A precise knowledge of the radar signature of snowpack is a pre-requisite towards quantitative retrieval of their physical parameters using SAR imagery from space. In view of the limited availability in the literature of radar scattering information of snowpack at X-band and above, the European Space Agency (ESA) has initiated experiments using a mast-mounted scatterometer. The objective of the measurements is to establish accurate data of snowpack scattering from X- to Ku-band together with relevant snowpack and meteorological parameters, continuously over complete snow seasons with a high temporal resolution.
ESAs SnowScat instrument is a real aperture scatterometer which was developed by Gamma Remote Sensing AG. It operates in a continuous wave mode, covers a frequency range of 9.15 (X-band) to 17.9 GHz (Ku-band) in a user-defined frequency-step and have a polarimetric capability. The measurement campaigns were started first in Feb. 2009 at Weissfluhjoch, Davos, Switzerland, as an initial test of the instrument. Physical characterisations of the snowpack as well as meteorological instrumentation provide detailed in-situ data for the interpretation of the SnowScat data. SnowScat was then moved to Sodankylä in Finland, a site of the Finnish Meteorological Institute in Lapland. In addition to the in-situ snowpack characterisations and meteorological observations, continuous passive microwave observations and direct measurements of the snow water equivalent using a Gamma Wave Instrument were also performed. During the 2012-2013 winter period, a vertical time-domain snow profiling experiment was carried out in addition for resolving the scattering contributions from the snow layers of different physical properties.
The SnowScat data set represents one of the most complete, detailed and accurate active microwave observation time-series of specific snowpacks at a local scale. This paper summarises the result of the SnowScat observations and their preliminary analysis against the in-situ snowpack data. The campaign data show that snowpack is a highly variable radar target at the SnowScat frequencies, showing strong dependency on continuous snow metamorphism of its microscopic structure which are further affected by meteorological events and their inter-annual variability. There appears to be no simple one-to-one relationship between the scattering radar cross-section and the snow depth, or its snow water equivalent.
LEMA (Laboratory of Electromagnetics and Acoustics)
Practical information
- General public
- Free
Organizer
- Michael Mattes
Contact
- Michael Mattes