ESA: SAR Workbench (SWB), a multi-mission EO data handling tool

Kurzfassung

An Italian company that has been operating in the Earth Observation (EO) industry for more than twenty years is offering a SAR Workbench (SWB). It is a modular desktop application for the management of multi-mission and multi-sensor data. It has a plug-in architecture that makes it very flexible and highly user friendly for all companies/institutions that work in image/data processing field. One of the innovative aspects is that it enables the user to manage EO data at lower levels.

Details

The Graphical User Interface (GUI) module (Geo-Spatial Data Viewer- GSDView) is mainly a lightweight EO data viewer written in Python and Qt4. It uses the powerful GDAL library (Geospatial Data Abstraction Library) for data access and provides support for more than 150 data formats. Its plug-in architecture enables GSDView to integrate and drive a potentially large range of data processors that are run as external processes.

Currently, a standard set of data processors for SAR (Synthetic Aperture Radar) data exist. These processors are written in C/C++ language in order to get adequate computational performances. The GUI component is mainly a multi-mission data viewer that includes facilities and graphical interfaces for controlling other modules. It currently supports a large number of SAR missions: COSMO-SkyMed, TerraSAR-X, Radarsat 1/2, PALSAR, ERS 1/2, and ENVISAT. It can also handle optical data, such as data from ENVISAT/MERIS and ALOS/AVNIR-2.

The viewer has been designed to be extremely user-friendly. It provides a dataset browser listing the available products, a main visualization area, a metadata viewer and a panel indicating the physical location of the image on a world map. Once a specific product is selected and visualized, the user can select a specific area of interest of the image and stretch it to further analyze it. Through the GUI interface the user can access the other modules available in SWB (SAR WorkBench).

Further to allowing access to multi-mission data, the “ingestion and data exchange” sub-system also enables the user to export data into standard graphic formats (GeoTIFF; JPEG, PNG) compatible with wide spread software tools and in formats specific for the main GIS (Geographic Information System) and EO applications. This is fundamental for the integration of SWB into scientific and production environments.

The Quality Analysis component includes tools for measurement of IRF (Impulse Response Function) parameters such as geometric resolution, PSLR (Peak Side Lobe Ratio), SSLR (Spurious Side Lobe Ratio), ISLR (Integrated Side Lobe Ratio) and IRF shape and tools for radiometric analysis. The Data Processing module includes a set of command line tools and processors that are specific for SAR data processing. Base functions provided include filtering, re-sampling, complex data detection without aliasing and geo-coding.

More advanced functions such as orthorectification, co-registration and interferometric processing are under development and will be available via external tools. One of the strong points of SWB is that it can be easily integrated with external tools thanks to its extensible architecture.

Innovative Aspects:
The main advantages of this offer include that scientists and application developers can greatly benefit from directly accessing low level EO data for their research. One of the innovative aspects of SWB is that it enables the user to manage the EO data even at lower levels. Another innovative feature, that very few SW products currently provide is the ability to perform quality analysis on EO products in order to check if the single product fits the requirements of the specific application. Finally, SWB is one of the few tools to manage COSMO-SkyMed data today.

This technology tool is capable of dealing in an efficient way with large Earth Observation (EO) data, especially if compared to traditional low level data of other available products such as SLC (Single Look Complex) SAR products. Low level data are generally considered inadequate for the final user or for publishing since their interpretation is quite hard. However low level products contain a lot of information, part of which is lost during higher level processing. Applications are usually targeted to a single aspect of the information contained in low level EO data. This is why the proposed technology offer is highly innovative with respect to other available solutions.