A proposal to develop new algorithms using Tandem-X SAR data has been accepted by the German Aerospace Center (DLR). Tandem-X offers fantastic new opportunities to explore novel SAR products and develop new (quantitative) geophysical measurements and tools. The abstract is below:
The project will: -evaluate TanDEM-X bistatic mode interferometric data for glacier mass balance and snowpack monitoring during dry snow and snowmelt conditions -investigate PolSAR and PolInSAR methods for the retrieval of snow and firn parameters and for the investigation of scattering processes near the equilibrium line -investigate PolSAR and PolInSAR methods for the quantification of biomass in a low density northern forest METHODS Using repeat pass DEMs created using bistatic mode TanDEM-X acquisitions we will use InSAR methods to determine surface height changes. With reference to a DEM generated under snow free conditions we will use a DInSAR approach to differentiate the surface heights and extract the snow volume. The effect of snow density, surface roughness, and liquid water content will investigated using field surveys. Data will be acquired over Blåmannsisen, for mass balance estimation, and from the Daja valley, for terrestrial snowpack volume estimates. DEMs will be generated under both dry snow and snow melt conditions. We will also evaluate the effect of vegetation type and biomass on polarimetric SAR scattering to test the potential for the derivation of a cross-pol proxy for snow volume during the peak snow melt period. Furthermore, we use experimental mode polarimetric acquisitions to decompose scattering. Results from PALSAR and Radarsat-2 data have shown strong correlations between the decomposed volume AND surface scattering at the equilibrium line of Blåmannsisen, suggesting layering in the firn is an important contributor to backscattered power in shallow firn. Decompositions such as Freeman-Durden and Pauli basis will be produced. Polarimetric interferograms will be produced to investigate the effect of the polarisation on interferogram quality and accuracy. PolInSAR acquisitions will allow us to apply polarimetric phase and coherence height estimates to determine the height (or depth) of dominant volume scattering in the Daja valley forest and the firn of Blåmannsisen, using cross-pol data as representative of volume scattering and horizontally co-polarised data as the surface scattering dataset. DATA REQUIREMENTS The project will require four bistatic mode acquisitions in 2012 to produce differential interferograms for snow pack and mass balance estimation. One monostatic and one alternating bistatic acquisition will also be requested in 2012 for comparative analysis of the data. In 2013 three bistatic experimental mode polarimetric datasets are requested for PolInSAR analysis and two alternating bistatic mode acquisitons for multi-baseline comparions.