Earth Observation Science Research Articles

KALMAN FILTER FOR REMOVAL OF SCALLOPING AND INTER-SCAN BANDING IN SCANSAR IMAGES

Spaceborne synthetic aperture radar (SAR) plays more and more important role in Earth observation science, especially with ScanSAR mode which provides wide-swath coverage with moderate resolution. However, scalloping and inter-scan banding (ISB) are two major artifacts, which signiflcantly degrade the quality of ScanSAR images. In this paper, a novel technique for removal of scalloping and ISB in ScanSAR images is proposed. Scalloping and ISB artifacts are modeled by two-dimensional gain and ofiset parameters varying as function of both azimuth time and range position. The gain and ofiset parameters can be split into azimuth and range components. The variations of gain/ofiset with respect to azimuth and range positions would represent scalloping and ISB artifacts respectively. In the proposed technique, recursive and minimum mean square error (MMSE) estimates of azimuth gain/ofiset parameters are found out by using Kalman fllter for each azimuth location in a subswath by considering corresponding range samples as observation vector. Subsequently, range gain/ofiset parameters causing ISB artifacts are estimated by using Kalman fllter for each range positions by considering azimuth samples as observation vector. The MMSE estimates of gain/ofiset parameters are used to directly remove scalloping and ISB artifacts. The proposed scheme was applied on simulated as well as calibrated real ScanSAR images. The experimental results exhibited the potential of proposed technique to be used as post processing tool for enhancing ScanSAR image quality.

新一代SAR 对地观测技术特点与应用拓展

From the viewpoint of Earth observation mechanisms and the potential application of new generation synthetic aperture radar (SAR),four subjects are analyzed and discussed as follows:Technical characteristics and scientific aspects of new generation SAR,the latest developments in new generation SAR Earth observation studies,the key science and methodological issues of new generation SAR,and its future development.In China,systematic study of these subjects is required for research and application of the new generation SAR,from follow-through to innovation,to improve SAR Earth observation science and techniques,and to service the demand of many fields across the nation.

A visual digital library approach for time-oriented scientific primary data

Digital Library support for textual and certain types of non-textual documents has significantly advanced over the last years. While Digital Library support implies many aspects along the whole library workflow model, interactive and visual retrieval allowing effective query formulation and result presentation are important functions. Recently, new kinds of non-textual documents which merit Digital Library support, but yet cannot be fully accommodated by existing Digital Library technology, have come into focus. Scientific data, as produced for example, by scientific experimentation, simulation or observation, is such a document type. In this article we report on a concept and first implementation of Digital Library functionality for supporting visual retrieval and exploration in a specific important class of scientific primary data, namely, time-oriented research data. The approach is developed in an interdisciplinary effort by experts from the library, natural sciences, and visual analytics communities. In addition to presenting the concept and to discussing relevant challenges, we present results from a first implementation of our approach as applied on a real-world scientific primary data set. We also report from initial user feedback obtained during discussions with domain experts from the earth observation sciences, indicating the usefulness of our approach.

Stratospheric Satellites for Earth Observations

Abstract Advanced, robust, yet inexpensive observational platforms and networks of platforms will make revolutionary Earth science observations possible in the next 30 years. One new platform concept that is needed is a long-duration stratospheric balloon flying in a near-space environment and capable of remaining aloft for a year carrying a half ton of payload. We dub these platforms StratoSats for stratospheric satellites because they usually orbit the Earth in the stratosphere with an orbit period of 10–20 days. StratoSats can complement space satellites or play a completely independent role in Earth observation. Constellations of these platforms could steer themselves to desired locations and perform coordinated in situ and remote sensing observations of the Earth and its atmosphere. In principle, such constellations could easily surpass the capabilities of a single satellite for far less cost. NASA has defined stratospheric science measurement requirements and platform capabilities for several Earth ...

Ocean Monitoring Collaborations Between Europe and China: DRAGONESS Project Kickoff Meeting; Beijing, China, 11–12 October 2007

A coordinated, concerted action between Europe and China in ocean monitoring kicked off with its first meeting, held in Beijing.The project, named DRAGONESS (DRAGON in support of harmonizing European and Chinese marine monitoring for Environment and Security System), is funded by the European Union's (EU) Framework Programme for 3 years. Researchers from the two continents will establish an inventory of Chinese and European capacities in marine monitoring for environment and security in the framework of challenges identified within international programs such as Global Ocean Observing System, Global Earth Observing System of Systems, and Global Monitoring for Environment and Security. In particular, the DRAGONESS aims to (1) assess existing Chinese and European information products and services arising from integrated use of remote‐sensing, in situ observations, models, and data assimilation methods; (2) identify monitoring gaps and barriers (e.g., restrictive data availability); and (3) stimulate exchange and initiation of a new European‐Chinese partnership in Earth observation science and technology in support of global environmental monitoring.

Harmonization of Earth Observation Data: Global Change and Collective Action Conflict

ABSTRACT Earth observation by satellites is the basis for integrated scientific assessment of global environmental change. Institutional arrangements to coordinate Earth observation data collection efforts recognize harmonization as essential for the scientific assessments that are sought. The goal of harmonization is to achieve compatibility of data polices among the various Earth observation science missions. In this article, I discuss the concept of harmonization and evaluate how Earth observation data policies influence the implementation of harmonization through an examination of a number of relevant actors, strategies, and systems. This includes the Committee on Earth Observation Satellites, the Integrated Global Observing Strategy, the former International Earth Observing System, the Group on Earth Observations, the Global Earth Observation System-of-Systems, and the Earth observation programs in the United States and Europe. The results of this study indicate that the problem for realizing an optimal harmonization lies in the differing preferences among actors as to how harmonization is formulated and then implemented. A number of recommendations are put forward here that can ameliorate the problems concerning the implementation of harmonization.

Regional aerosol retrieval results from MISR

Examples of aerosol retrieval results, derived from the Multi-angle Imaging SpectroRadiometer (MISR) on the Earth Observation Science (EOS) Terra platform, are shown and the performance of the retrieval algorithms are discussed, following the first 18 months of operational data processing. A number of algorithm modifications were implemented, based on an analysis of aerosol retrieval results during this period, and these changes are described. Two cloud-screening algorithms, the angle-to-angle smoothness and angle-to-angle correlation tests, which were used in the preprocessing phase of the analyses are also described. The aerosol retrieval examples cover a wide variety of conditions, both over land and water. Particular aerosol types include dust clouds, forest fire and volcanic plumes, and localized dense haze. Finally, some ideas are discussed for additional improvement of the MISR aerosol data product, based on the experience gained in analyzing multiangle data and the associated geophysical products.

Barriers to the diffusion and uptake of BRDF research and methods

Despite a long and successful history, involving both measurements and models, the diffusion of research and the uptake of methods involving multi‐angle data and Bidirectional Reflectance Distribution Function (BRDF) models have been surprisingly limited. This paper examines the probable cultural, educational, technical and practical reasons for this and advances a number of possible solutions. More specifically, it examines issues relating to (i) the adoption of new scientific methods by the Earth observation and Earth science communities, (ii) the impact of access to appropriate directional reflectance data and software, and (iii) the role of educators and teaching material as agents for reinforcing existing scientific paradigms and promulgating new ones. The discussion is based upon observations by the authors and conversations with others in the bidirectional reflectance research arena, students of remote sensing, and the wider community concerned with the practical applications of remote sensing. The...

Development of a sea-ice workstation for the automated monitoring of sea ice

AbstractUK-based operations that range from ship routing and resource exploration to weather forecasting and glaciology have direct and growing interests in the oceans of the polar regions. Typically, information describing sea-ice conditions in localised regions is required on short time scales. To explore this market, the UK's Defence Research Agency, as part of a programme of the British National Space Centre, has commissioned the development of a prototype sea-ice workstation by a consortium led by Earth Observation Sciences Ltd.The sea-ice workstation (SIWS) uses data from several current earth observation sensors, thereby combining the advantages of regional survey, all-weather capability, and high-resolution imagery. The workstation has been designed to run with a minimum of operator intervention in order to optimise speed of operation and ensure consistency of results. The geophysical processing chains generate charts of the ice edge, ice type, ice concentration, ice-motion vectors, and sea-surface temperatures.Although taking full advantage of developments made elsewhere, the project has also made significant progress in research into the automated mapping of ice types. Existing ice-motion algorithms have been significantly enhanced as well. Considerable emphasis is being placed on the validation of the results from the system in order to assess their quality, this being one of the major concerns of potential users. The sea-ice workstation was completed in July 1994 and will form the basis for a series of evaluations that are intended to assess the value of the system for mapping and monitoring sea ice.

Experimental studies on the performance of Hg 0.8 Cd 0.2 te photoconductors operating near 200 K

The performance and noise characteristics of an 8–12 μm HgCdTe photoconductor at temperatures above 77 K are investigated. The result is of interest for a passively cooled spacecraft EOS (Earth Observation Science) mission.

The Evolution of the Geostationary Platfom Concept

The paper will review the conceptual development over the last decade of the use of very large spacecraft, i.e., "platforms," in geostationary orbit. Geostationary platforms were originally conceived as an efficient means of increasing the capacity at a point in the geostationary orbital arc. This geostationary platform was seen as a solution to the predicted crowding of the orbital arc since it could provide the functions of many individual satellites of conventional design. Also, geostationary platforms have been suggested for mounting very large antennas as will be required for mobile communications, or high power sources as will be required for broadcast services to small terminals. More recently these "large satellite" platforms were also envisioned as including earth observation and other science payloads. The advent of the Space Station which can provide a staging base for platform assembly and test in space at low earth orbit (LEO), prior to launch to geostationary earth orbit (GEO), will introduce a new dimension to practical platform design. This dimension has reintroduced the geostationary platform concept as a potential communications and science spacecraft of the post-IOC-Space Station family. This paper describes the evolution of concepts for geostationary platforms over the last decade based on both communications and science user scenarios developed worldwide.

The European Columbus Programme

This paper describes the current status of the COLUMBUS Programme, Europe's contribution to the U.S. Space Station, which is being studied under contract to the European Space Agency. Twelve European nations are involved in and are contributing to this new space undertaking. The elements of the COLUMBUS Space Segment presently being considered by ESA are a Pressurized Laboratory Module (4 segment), permanently attached to the U.S. Space Station, dedicated to materials science, fluid physics and compatible life sciences, and a Polar Platform, configured to accommodate Earth observation, meteorology, communications and space science payloads. The reference launch vehicles are the Space Shuttle for the attached Module and Ariane 5 for the Polar Platform. The more recently added COLUMBUS flight configuration, the Man-Tended Free Flyer (MTFF), consists of a combination of two programme elements, the Resource Module and a 2-segment Pressurized Module. It is designed to provide all required resources and services to the various payloads in a continuous microgravity environment to perform material science, fluid physics and compatible life sciences experiments. The MTFF is carried into orbit by the European launcher Ariane 5. As an option, studies of an enhanced ground based EURECA carrier as a small co-orbiting platform, launched by the Space Shuttle, will be initiated. The primary function would be to accommodate space science and/or micro-g payloads. These EURECA studies are performed currently outside the COLUMBUS programme scope, and this option is therefore not addressed in detail in this paper.