POLSARpro v 3 . 0 : THE VERSATILE EDUCATIONAL TOOLBOX FOR POLARIMETRIC AND INTERFEROMETRIC SAR DATA PROCESSING

The objective of this paper is to make a review of the current status of the PolSARpro v3.0 Software (Polarimetric SAR Data Processing and Educational Toolbox), developed under contract to ESA by a consortium comprising I.E.T.R at the University of Rennes 1, AELc, DLR-HR and Dr mark Williams from Adelaide. The objective of this current project is to provide Educational Software that offers a tool for self-education in the field of Polarimetric SAR data analysis at University level and a comprehensive suite of functions for the scientific exploitation of fully and partially polarimetric multi-data sets and the development of applications for such data. The PolSARpro v3.0 Software establishes a foundation for the exploitation of Polarimetric techniques for scientific developments and stimulates research and applications developments using PolSAR and PolInSAR data.. 1. CONTEXT AND PRINCIPAL OBJECTIVES SAR remote sensing allows all weather, global scale imaging and estimation of important bio and geophysical parameters about the Earth's surface. It is achieved by sensing scattered electromagnetic fields reflected from the Earth surface when emitted by an electromagnetic energy source situated on an aircraft, spacecraft or satellite outside of the Earth's atmosphere. The development of multi-parameter SAR techniques such as Polarimetric SAR (POLSAR) and Polarimetric Interferometric SAR (POLinSAR) is advancing rapidly, and these novel radar technologies are constantly extending decisively the range of applications of radar in remote sensing. Due to new polarimetric radar sensors (ENVISAT ASAR, ALOS-PALSAR and the future TerraSAR-X and RADARSAT-2), it is now shown that the accelerated advancement of POLSAR techniques is of direct relevance and of priority to localto-global environmental ground-truth measurement and validation, stress assessment, and stress-change monitoring of the terrestrial and planetary covers. POLSAR and POLINSAR remote sensing techniques offer efficient and reliable means of collecting information required to extract biophysical and geophysical parameters about the Earth's surface and have found successful applications in crop monitoring and damage assessment, in forestry clear cut mapping, deforestation and burn mapping, in land surface structure (geology) land cover (biomass) and land use, in hydrology (soil moisture, flood delineation), in sea ice monitoring, in oceans and coastal monitoring (oil spill detection) etc ... Due to, both, the ESA’s desire to augment his collection of software packages, known as the Envisat Toolboxes, and the feedback from the Workshop on “Applications of SAR Polarimetry and Polarimetric Interferometry”, held at ESA-ESRIN, Frascati, Italy, on 14-16 January 2003, it was proposed to expand the existing PolSARpro software to handle data from current and future spaceborne missions (in addition to those airborne missions already supported), thus providing a comprehensive suite of functions for the scientific exploitation of fully and partially polarimetric data and the development of applications for such data. PolSARpro v2.0 was developed under contract to ESA (“Development of a Polarimetric SAR Image Analysis Tool”, ESA–ESRIN Contract n° 17863/03/I– LG). Today a new version of the sotfware (PolSARpro v3.0) is continued to be developed under contract to ESA (“Continued Development of PolSARpro Software”, C.C.N to ESA–ESRIN Contract n° 17863/03/I–LG) by a consortium comprising I.E.T.R at the University of Rennes 1, DLR-HR, AELc and Dr Mark L. Williams. Figure n°1 proposes the PolSARpro v3.0 Main Entry Screen in its actual version. The objective of the current project is to provide an Educational Software that offers a tool for selfeducation in the field of Polarimetric SAR data analysis at University level and a comprehensive suite of functions for the scientific exploitation of fully and partially polarimetric multi-data sets and the development of applications for such data. The PolSARpro v3.0 Software will establish a foundation for the exploitation of Polarimetric techniques for scientific developments and stimulate research and applications developments using PolSAR and PolInSAR data. POLSARpro v3.0: THE VERSATILE EDUCATIONAL TOOLBOX FOR POLARIMETRIC AND INTERFEROMETRIC SAR DATA PROCESSING _____________________________________________________ Proc. ‘Envisat Symposium 2007’, Montreux, Switzerland 23–27 April 2007 (ESA SP-636, July 2007) Figure n°1 : PolSARpro v3.0 Main Entry Screen 2. SOFTWARE PORTABILITY AND DEVELOPMENT LANGUAGE PolSARpro v3.0 Software is developed to be accessible to a wide range of users, from novices (in terms of training) to experts in the field of Polarimetry and Interferometric Polarimetric SAR data processing. For this, the tool is conceived as a flexible environment, proposing a friendly and intuitive graphical user interface (GUI), enabling the user to select a function, set its parameters and run the software. The PolSARPro v3.0 software is a complementary Toolbox to existing commercial SAR image processing packages (ENVI, PCI ...) and must be considered as a Polarimetric SAR data processing software which proposes wellestablished algorithms in the field of polarimetric and polarimetric-interferometric radar signal processing with high-level functionalities for in-depth analysis and for the scientific exploitation of fully and partially polarimetric data to the development of the corresponding remote sensing applications. The PolSARPro v3.0 software proposes a graphical user interface (GUI) written in Tcl-Tk (more than 263369 lines managing 154 widget windows) and contains today around 681 C routines (279839 lines) which perform the different processing functions. All the development languages and compilers used in PolSARpro are open source and completely free. There is no use of any 4 generation programming languages (such as IDL or MATLAB) thus avoiding any licensing problem and associated cost. The PolSARPro v3.0 software runs today on the following platforms: Windows 98+, Windows 2000, Windows NT 4.0, Windows XP, Linux I386, UnixSolaris and tomorrow on Macintosh OS. As the software will be made available following the Open Source Software Development (OSSD) approach, where the source code of the C Routines will be made available for free download on the Internet, it is thus possible for the users to develop additional new modules following the flexible structure of the environment. Users can easily understand how modules can be extracted from the Tool, modified and / or incorporated into their own systems. As it can be seen, the proposed open software environment approach enables the user to select a function, set its parameters and run the routine on his own system, independently of the PolSARPro environment. This approach can also encourage users to modify the routines to meet their individual requirements, and then to share the fruits of their work with other users. 3. PolSARpro v3.0 MAIN MENU The PolSARpro V3.0 Software proposes a great collection of well-established algorithms and tools designed for the analysis of only Single and Multi Data Sets Polarimetric SAR data with specialized functionalities for in-depth analysis of fully and partially polarimetric data and the development of applications for such data. Specific interfaces dedicated to different Polarimetric Spaceborne Sensors (ALOS, ASAR, RADARSAT2, TerraSAR-X, SIRc) or Polarimetric Airborne Sensors (AIRSAR, Convair, EMISAR, ESAR, PISAR, RAMSES) data processing can be selected from the main menu by clicking on the Sensor associated button. The Main Menu of the software is shown on figure n°2. Figure n°2: PolSARpro v3.0 Main Menu Window Specific complementary functionalities as Tutorial, Help; Tools, Create BMP and Viewer can be selected from the main menu by clicking on the corresponding button. The PolSARpro v3.0 software can process polarimetric or partially polarimetric data sets under many different formats. The different polarimetric data formats handled by PolSARpro v3.0 are the following: The (2x2) complex Sinclair [S2] matrix, the (3x3) and (4x4) complex Coherency [T3], [T4] or Covariance [C3], [C4] matrices and Partial Polarimetry representation. 4. EDUCATIONAL SOFTWARE Due to the polarimetric radar sensors (ENVISAT ASAR, ALOS-PALSAR and the future RADARSAT-2 and TerraSAR-X), it is now shown that the accelerated advancement of POLSAR techniques is of direct relevance and of priority to local-to-global environmental ground-truth measurement and validation, stress assessment, and stress-change monitoring of the terrestrial and planetary covers. Scientists and engineers already engaged in the fields of radar remote sensing generally gain their specialist knowledge in polarimetry by working through scientific papers and specialized literature available on the subject. The aim of this Tutorial is to provide a substantial and balanced introduction to the basic theory, scattering concepts, systems and advanced concepts and applications typical to Radar Polarimetry and Interferometry. This Tutorial on Radar Polarimetry is completed with a review of some important aspects of radar polarimetry and interferometry to learn how to generate multiple polarization interferograms and how to use them with simple inversion models to estimate surface parameters, vegetation height and ground topography. This tutorial can be used as a low level teaching aid for polarimetric SAR processing and is illustrated with application examples showing the full range of functions that the Tool offers (Do it yourself sections). The PolSARpro v3.0 software is thus provided with a comprehensive indepth documentation permitting self-education to a high level (radar experts and post graduate students). User has access to this wide-ranging tutorial, available in PDF format, providing grounding in SAR Polarimetry (PolSAR) and SAR Polarimetric Interferometry (POLinSAR) from the main menu. User have also access to different series of Tutorial Slide Shows, that are made available to support taught courses of for use as part of a self teaching programme. The PolSARpro V3.0 Software is also accompanied by a detailed set of 228 Help Files, made available in PDF format, for each individual function. The User Manual provides comprehensive documentation of the software. As each new version of the PolSARpro v3.0 software becomes available, extra content will be