High Performance Computing in Remote Sensing - Chapter 11

Chapter 11 Open Grid Services for Envisat and Earth Observation Applications Luigi Fusco, European Space Agency Roberto Cossu, European Space Agency Christian Retscher, European Space Agency Contents 11.1 Introduction .......................................................... 239 11.2 ESA Satellites, Instruments, and Products ............................. 239 11.2.1 ERS-2 ....................................................... 240 11.2.2 Envisat ....................................................... 240 11.3 Example of Specialized User Tools for Handling ESA Satellite Data ... 242 11.3.1 BEST ........................................................ 243 11.3.2 BEAM ....................................................... 243 11.3.3 BEAT ........................................................ 245 11.4 Grid-Based Infrastructures for EO Data Access and Utilization ......... 246 11.4.1 Service Support Environment ................................. 249 11.4.2 GeoNetwork ................................................. 249 11.4.3 CCLRC DataPortal and Scientific Metadata Model ............ 250 11.4.4 Projects@ReSC .............................................. 250 11.4.5 OPeNDAP ................................................... 251 11.4.6 DataGrid and Follow-up ...................................... 251 11.4.7 CrossGrid .................................................... 252 11.4.8 DEGREE .................................................... 253 11.5 ESA Grid Infrastructure for Earth Science Applications ................ 254 11.5.1 Infrastructure and Services ................................... 254 11.5.2 The GRID-ENGINE ......................................... 255 11.5.3 The Application Portals ...................................... 256 11.5.3.1 An Example of an Application Portal: Computation and Validation of Ozone Profile Calculation Using the GOME NNO Algorithm ...... 258 237 © 2008 by Taylor & Francis Group, LLC 238 High-Performance Computing in Remote Sensing 11.6 EO Applications Integrated on G-POD ................................ 259 11.6.1 Application Based on MERIS and AATSR Data and BEAM Tools ............................................. 259 11.6.1.1 MERIS Mosaic as Displayed at EO Summit in Brussels, February 2005 ......................... 259 11.6.1.2 MERIS Global Vegetation Index .................... 260 11.6.1.3 MERIS Level 3 Algal 1 ............................ 260 11.6.1.4 Volcano Monitoring by AATSR .................... 261 11.6.2 Application Based on SAR/ASAR Data and BEST Tools ...... 261 11.6.2.1 A Generic Environment for SAR/ASAR Processing ......................................... 261 11.6.2.2 EnviProj – Antarctica ASAR GM Mapping System ............................................ 263 11.6.2.3 ASAR Products Handling and Analysis for a Quasi Systematic Flood Monitoring Service ... 263 11.6.3 Atmospheric Applications Including BEAT Tools ............. 265 11.6.3.1 GOME Processing ................................. 265 11.6.3.2 3D-Var Data Assimilation with CHAMP Radio Occultation (RO) Data ....................... 265 11.6.3.3 YAGOP: GOMOS Non-operational Processing ..... 266 11.6.3.4 GRIMI-2: MIPAS Prototype Dataset Processing .... 268 11.6.3.5 SCIA-SODIUM: SCIAMACHY Sodium Retrieval .. 268 11.7 Grid Integration in an Earth Science Knowledge Infrastructure ......... 270 11.7.1 Earth Science Collaborative Environment Platform and Applications – THE VOICE .............................. 271 11.7.2 Earth Science Digital Libraries on Grid ....................... 272 11.7.3 Earth Science Data and Knowledge Preservation .............. 273 11.7.4 CASPAR ..................................................... 274 11.7.5 Living Labs (Collaboration@Rural) ........................... 275 11.8 Summary and Conclusions ............................................ 275 11.9 Acknowledgments .................................................... 277 References .................................................................. 277 The ESA Science and Application Department of Earth Observation Programmes Directorate at ESRIN has focused on the development of a dedicated Earth Science grid infrastructure, under the name Earth Observation Grid Processing On-Demand (G-POD).Thisenvironmentprovidesanexampleoftransparent,fast,andeasyaccess to data and computing resources. Using a dedicated Web interface, each application has access to the ESA operational catalogue via the ESA Multi-Mission User Inter-face System (MUIS) and to storage elements. It furthermore communicates with the underlyinggridmiddleware,whichcoordinatesallthenecessarystepstoretrieve,pro-cess, and display the requested products selected from the large database of ESA and third-party missions. This makes G-POD ideal for processing large amounts of data, developing services that require fast production and delivery of results, comparing scientist approaches to data processing, and permitting easy algorithm validation. © 2008 by Taylor & Francis Group, LLC Open Grid Services for Envisat and Earth Observation Applications 239 11.1 Introduction FollowingtheparticipationoftheEuropeanSpaceResearchInstitute(ESRIN)atESA in DataGrid, the first large European Commission funded grid project [1], the ESA Science and Application Department of Earth Observation Programmes Directorate hasfocusedonthedevelopmentofadedicatedEarthSciencegridinfrastructure,under thenameEarthObservationGridProcessingon-Demand[2].Thisgenericgrid-based environment (G-POD) ensures that specific Earth Observation (EO) data handling andprocessingapplicationscanbeseamlesslypluggedintothesystem.Coupledwith high performance and sizeable computing resources managed by grid technologies, G-PODprovidesthenecessaryflexibilityforbuildingavirtualenvironmentthatgives applicationsquickaccesstodata,computingresources,andresults.Usingadedicated Web interface, each application has access to a catalogue like the ESA Multi-Mission User Interface System (MUIS) and storage elements. It furthermore communicates with the underlying grid middleware, which coordinates all the necessary steps to retrieve, process, and display the requested products selected from the large database of ESA and third-party missions. Grid On-Demand provides an example of transparent, fast, and easy access to data and computing resources. This makes G-POD an ideal environment for processing large amounts of data, developing services that require fast production and deliv-ery of results, comparing approaches, and fully validating algorithms. Many other grid-based systems are being proposed by various research groups using similar and alternative approaches, although sharing the same ambition for improved integration of the emerging Information and Communication Technologies (ICT) technologies exploitable by the Earth Science community. In the Sections 11.2 and 11.3 we give an overview of selected ESA Earth Ob-servation missions and related software tools that ESA provides for facilitating data handling and analysis. In Section 11.4 we describe how the EO community can ben-efit from grid technology for data access and sharing. In this context, some examples of ESA and EU projects are described. Section 11.5 describes in detail the G-POD environment, its infrastructure, the intermediary layer developed to interface with the application, and the grid computer and storage resources, the Web portals. Differ-ent examples of EO applications integrated in G-POD are described in Section 11.6. Section11.7brieflydocumentstheuseofgridtechnologyinEarthScienceKnowledge Infrastructures. Conclusions are drawn in Section 11.8. 11.2 ESA Satellites, Instruments, and Products ThissectionbrieflyoverviewstheESAEuropeanRemoteSensingsatellite(ERS)and Envisat missions and the sensors on-board these satellites, with special attention to the data used in the context of ESA’s activities on grids. © 2008 by Taylor & Francis Group, LLC 240 High-Performance Computing in Remote Sensing 11.2.1 ERS-2 The ERS-2 Earth Observation mission [3] has been operating since 1995. The ERS-2 satellitecarriesasuiteofinstrumentstoprovidedataforscientificandcommercialap-plications. ERS-1, the ERS-2 predecessor, was launched in July 1991 and was ESA’s first sun-synchronous polar-orbiting remote sensing mission, operated until March 2000. It continued to provide excellent data, far exceeding its nominal lifetime. ERS-2 is nearly identical to ERS-1. The platform is based on the design developed for the French SPOT satellite. Payload electronics are accommodated in a box-shaped hous-ing on the platform; antennas are fitted to a bearing structure. On-board ERS-2 there are seven instruments to support remote sensing applications: RA, ATSR, GOME, MWR, SAR, WS, and PRARE. In particular we wish to refer to: r SAR: Synthetic Aperture Radar (SAR) wave mode provides two-dimensional spectra of ocean surface waves. For this function the SAR records regularly spaced samples within the image swath. The images are transformed into di-rectional spectra providing information about wavelength and the direction of the wave systems. Automatic measurements of dominant wavelengths and di-rections will improve sea forecast models. However, the images can also show theeffectsofotherphenomena,suchasinternalwaves,slicks,small-scalevari-ations in wind, and modulations due to surface currents and the presence of sea ice. r GOME: The GOME instrument, which stands for Global Ozone Monitoring Experiment, is a newly developed passive instrument that monitors the ozone content of the atmosphere to a degree of precision hitherto unobtainable from space. This highly sophisticated spectrometer was developed by ESA in the record time of five years. GOME is a nadir-scanning ultraviolet and visible spectrometer for global monitoring of atmospheric ozone. It was launched on-boardERS-2inApril1995.Sincethesummerof1996,ESAhasbeendelivering to users three-day GOME global observations of total ozone, nitrogen dioxide, and related cloud information, via CD-ROM and the Internet. A key feature of GOME is its ability to detect other chemically active atmospheric trace gases as well as the aerosol distribution. r ATSR: The Along-Track Scanning Radiometer consists of an InfraRed Ra-diometer (IRR) and a Microwave Sounder (MWS). On-board ERS-1, the IRR is a four-channel infrared radiometer used for measuring sea-surface tempera-tures (SST) and cloud-top temperatures, whereas on-board ERS-2 the IRR is equipped with additional visible channels for vegetation monitoring. 11.2.2 Envisat The Environmental Satellite (Envisat) [4] is an advanced polar-orbiting Earth Ob-servation satellite that provides measurements of the atmosphere, ocean, land, and ice. The Envisat satellite has an ambitious and innovative payload that ensures the © 2008 by Taylor & Francis Group, LLC Open Grid Services for Envisat and Earth Observation Applications 241 continuity of the data measurements of the ERS satellites. The Envisat data sup-port Earth Science research and allow monitoring of the evolution of environmental and climatic changes. Furthermore, they facilitate the development of operational and commercial applications. On-board Envisat there are ten instruments: ASAR, MERIS,AATSR,GOMOS,MIPAS,SCIAMACHY,RA-2(RadarAltimeter2),MWR (Microwave Radiometer), DORIS (Doppler Orbitography and Radio-positioning), LRR (Laser Retro-Reflector). In particular we wish to refer to: r ASAR:ASARistheAdvancedSyntheticApertureRadar.OperatingatC-band, it ensures continuity with the image mode (SAR) and the wave mode of the ERS-1/2 AMI (Active Microwave Instrument). It features enhanced capability in terms of coverage, range of incidence angles, polarization, and modes of operation. This enhanced capability is provided by significant differences in the instrument design: a full active array antenna equipped with distributed transmit/receive modules that provide distinct transmit and receive beams, a digital waveform generation for pulse ‘chirp’ generation, a block adaptive quantization scheme, and a ScanSAR mode of operation by beam scanning in elevation. r MERIS: MERIS is a programmable, medium-spectral resolution imaging spectrometer operating in the solar reflective spectral range. Fifteen spec-tral bands can be selected by ground command, each of which has a pro-grammable width and a programmable location in the 390 nm to 1040 nm spectral range. The instrument scans the Earth’s surface by the so-called push-broom method. Linear CCD arrays provide spatial sampling in the across-track direction, while the satellite’s motion provides scanning in the along- track direction. MERIS is designed so that it can acquire data over the Earth whenever illumination conditions are suitable. The instrument’s 68.5◦ field of view around nadir covers a swath width of 1150 km. This wide field of view is shared between five identical optical modules arranged in a fan-shape configuration. r AATSR: The Advanced Along-Track Scanning Radiometer (AATSR) is one of the Announcement of Opportunity (AO) instruments on-board Envisat. It is the most recent in a series of instruments designed primarily to mea-sure Sea Surface Temperature (SST), following on from ATSR-1 and ATSR-2 on-board ERS-1 and ERS-2. AATSR data have a resolution of 1 km at nadir and are derived from measurements of reflected and emitted radiation taken at the following wavelengths: 0.55 μm, 0.66 μm, 0.87 μm, 1.6 μm, 3.7 μm, 11 μm, and 12 μm. Special features of the AATSR instrument include its use of a conical scan to give a dual view of the Earth’s sur-face, on-board calibration targets, and use of mechanical coolers to main-tain the thermal environment necessary for optimal operation of the infrared detectors. r GOMOS: The Global Ozone Monitoring by Occultation of Stars instrument is amedium-resolutionspectrometercoveringthewavelengthrangefrom250nm © 2008 by Taylor & Francis Group, LLC ... - tailieumienphi.vn