|Paper title||Algorithms development and integration of multi-frequency SAR data from national and Copernicus missions towards scientific downstream applications|
|Form of presentation||Poster|
The present paper aims to showcase the portfolio of R&D activities that in these years the Italian Space Agency (ASI) is carrying out in collaboration with the national research community, to address scientific applications based on the exploitation of Synthetic Aperture Radar (SAR) data from the national mission COSMO-SkyMed, as well as Copernicus and other bilateral cooperation missions (e.g. SAOCOM).
The focus is on algorithms development and integration of multi-mission SAR data that are collected at different wavelengths, in light of the current unprecedentedly wide spectrum of observations of the Earth’s surface ranging from X- to L-band provided by SAR missions in Europe and beyond.
Within such a framework, COSMO-SkyMed First Generation, TerraSAR-X, Sentinel-1 and ALOS-2 satellites have been operating since several years. On the other side, SAOCOM, NovaSAR, COSMO-SkyMed Second Generation and RADARSAT Constellation Mission satellites have been successfully launched starting from late 2018. Therefore, the geoscience and remote sensing community is increasingly provided with: (i) continuity of observations with respect to previous SAR missions; (ii) opportunities to task collection of spatially and temporally co-located datasets in different bands.
The challenge is now to develop processing algorithms that can make the best out of this multi-frequency observation capability, in order to address a multitude of scientific questions and downstream applications. These applications include, but are not limited to: retrieval of geophysical parameters; land cover classification; interferometric (InSAR) analysis of ground deformation and for structural health monitoring; generation of value added products useful to end-users and stakeholders, for example for civil protection, disaster risk reduction, resilience building, sustainable use of natural resources.
In the framework of the ASI’s roadmap towards the development of SAR-based scientific downstream applications, recent R&D projects have act as the foundational steps to define, develop and test new algorithms for SAR data processing and integration. The R&D activities have intentionally focused from the statement of the initial scientific idea (Scientific Readiness Level – SRL 1, according to ESA EOP-SM/2776 scale) to, at least, the demonstration of the proof of concept (SRL 4) through extensive analyses by means of dedicated experiments and ground-truth validation.
Building upon this heritage and in order to move forwards (also in terms of higher SRL), ASI has recently launched a dedicated programme named “Multi-mission and multi-frequency SAR”. It supports R&D projects proposed by leading experts in the fields from national public research bodies and industry – also in the framework of international partnerships – to design, develop and test innovative methods, techniques and algorithms for exploitation of multi-mission/multi-frequency SAR data, with credible perspectives of engineering and pre-operational development, thus being able to contribute to the improvement of socio-economic benefits of the end-user community.
The current projects address the following R&D areas of specific interest: agriculture, urban areas, natural hazards, cryosphere, sea and coast; alongside the common cross-cutting topic of validation of products generated from multi-frequency SAR data by using ground-truth data (Figure 1).
In light of the experiences gained during recent R&D projects and at nearly one year since the initiation of the multi-mission and multi-frequency SAR projects, the present talk will outline the novelty of the methodological approaches under testing and demonstration, ongoing activities and results achieved, with a particular focus on the integration of Sentinel-1, COSMO-SkyMed, SAOCOM and ALOS-2 data.
Discussion will include:
- Lessons learnt about the role played by regularly acquired multi-frequency and multi-mission SAR time series (also in combination with other EO data) for observation continuity and investigation of long-term processes, either natural and anthropogenic ones;
- Benefits and limitations of acquisition programmes over the national territory and across different locations in the world vs. user requirements;
- The added value brought by the polarimetric SAR capability, e.g. for retrieval approaches of geophysical parameters;
- The importance of coupling satellite observations with instrumented sites and contextual surveys, for both calibration/validation activities and integrated analyses;
- Reflections about the perspectives towards future pre-operational implementation in scientific downstream applications.