Earth observation data archiving in the USA and Europe

The growing number of Earth observation satellites are producing exponential increases in the amount of data produced. These data sets contain valuable information on the state of the environment to accurately monitor and predict the impact of global change. Global change investigations require access to long-term data. This paper is a review of the current archiving practices of NOAA, NASA, SPOT, ESA and the DLR. It is demonstrated that despite recognition at a regional and organisational level of the importance of data archiving much work remains to be done. Funding responsibility is identified as a particularly problematic area of data archiving: it is an issue along with the need for easy accessibility and adequate metadata that will need to be resolved to ensure that future generations have access to adequate Earth observation data archives.     

European perspectives on trends in public sector Earth observation data policies

The growing number of Earth observation satellites are producing ever increasing amounts of data. These data sets require adequate management to be widely exploited and to ensure preservation of what is a valuable information resource. Many Earth observation organisations have formulated or are developing policies related to how data are managed and distributed which encompass issues such as property rights, access and price of the data, exclusive data use and data archiving. European Earth observation is gaining more prominence in these developing policy issues. This paper is a review, from a largely European perspective, of current Earth observation data policies in operation by various public sector international, regional and national organisations in both the data providing and data user sectors. It will be demonstrated that certain trends exist between the various data policies but that differences in position are present in some key areas which may need to be reconciled in order for the Earth observation sector to reach maturity.     

Earth observation and the public good

The term ‘public good’ is often used in satellite Earth observation to indicate that Earth observation data are of value or interest to the public. In fact, the term ‘public good’ has a more specific meaning, originating in the discipline of Economics, which carries with it a set of assumptions and implications about how markets operate. In this context a public good has two main characteristics: non-rivalry and non-excludability. In their most common digital format, Earth observation data can appear to be both non-rivalrous and non-excludable. However, it is not the digital medium itself which controls the ‘publicness’ of a good but the conditions of access to that good. This paper explores the meaning of the concept of public goods in an Earth observation context by, first, examining public good theory and related concepts of categories of goods and, second, applying the concepts to nine Earth observation missions, programmes and data.     

Continuity of moderate resolution Earth observation data: is an international solution the answer?

The operation of the US Landsat-7, launched in 1999, has proved a marked success. Together with the earlier Landsat data stored at the US Geological Survey Earth Data Analysis Center and other centers around the world, Landsat 7 data constitute a powerful tool for analyzing changes in the Earth's surface. However, the continuity of the Landsat system is not assured. An international system in which other countries participate could provide a more robust system, while spreading the costs and benefits of supplying such data more broadly. This paper explores the potential for creating an international arrangement to supply data of moderate resolution and extensive coverage in order to contribute to planetary stewardship, and discusses several different implementation approaches.     

Microwave policy issues for solar space power

This article reviews the three major policy issues likely to arise from an SSP system: environmental safety, frequency allocation and prevention of interference with other frequency-using activities. Supporters of SSP must make sure that their case is heard clearly at the ITU, but they must also do more to promote public awareness of the technology's potential benefits in order to counter inappropriate use of the Precautionary Principle by anti-technology groups. The strengthening of standard-setting groups world-wide will also assist this process.     

Supporting multilateral environmental agreement with satellite Earth observation

The purpose of this paper is to provide an overview of the potential contribution of satellite Earth observation (EO) to implementing and ensuring compliance with Multilateral Environmental Agreements (MEAs) from the institutional and legal point of view. EO has recently been recognized as an effective means to satisfy the demand for environmental information required by MEAs; however, actual usage of EO data in MEA implementation and compliance assurance has not yet made significant progress. While EO's legal and technical characteristics appear relevant to such applications, institutional linkage and technical reliability are still missing. Further efforts to promote EO data use for MEAs are needed through initiatives that link the EO system and data supplier with decision makers in the MEA community. The Japan Aerospace Exploration Agency's (JAXA) Kyoto and Carbon Initiative may be one example of such efforts. Recent movements, such as the Group on Earth Observation (GEO), could also provide an ideal focal point for coordinating and developing globally integrated EO and data utilization systems that could facilitate MEA implementation and compliance.     

中国陆地观测卫星第三届用户大会召开

中国资源卫星中心于2009年7月16日在北京组织召开了中国陆地观测卫星第三届用户大会。大会的主旨为：加强合作。扩大共享。共同促进国产卫星数据的广泛应用。     

Astromedicine and astrolaw: Emerging issues for advanced missions beyond Earth orbit

It is generally agreed within the scientific community that provision of appropriate medical facilities and administration of quality health care to astronauts are of great importance. However, for the more complex and remote missions envisaged for the future, issues of liability, responsibility and damage relating to medical practice may take on a greater significance and will need to be addressed. The author briefly reviews potential issues which may arise in the context of medical emergencies, crew autonomy and environmentally altered physiological status which characterize some projected advanced space missions and argues that the law of outer space will need to be expanded to take account of them.     

Small satellite's role in future hyperspectral Earth observation missions

Along with various advanced satellite onboard sensors, an important place in the near future will belong to hyperspectral instruments, considered as suitable for different scientific, commercial and military missions. As was demonstrated over the last decade, hyperspectral Earth observations can be provided by small satellites at considerably lower costs and shorter timescales, even though with some limitations on resolution, spectral response, and data rate. In this work the requirements on small satellites with imaging hyperspectral sensors are studied. Physical and technological limitations of hyperspectral imagers are considered. A mathematical model of a small satellite with a hyperspectral imaging spectrometer system is developed. The ability of the small satellites of different subclasses (micro- and mini-) to obtain hyperspectral images with a given resolution and quality is examined. As a result of the feasibility analysis, the constraints on the main technical parameters of hyperspectral instruments suitable for application onboard the small satellites are outlined. Comparison of the data for designed and planned instruments with simulation results validates the presented approach to the estimation of the small satellite size limitations. Presented analysis was carried out for sensors with conventional filled aperture optics.     

The US national space transportation policy: issues for congress

Below is a summary of what was to be the first in a series of reports produced by the Office of Technology Assessment (now defunct) on policy for the USA's future space transportation technology and industrial base. It examines the Clinton Administration's 1994 National Space Transportation Policy and supporting implementation plans and raises and analyses such issues as conflicts and redundancies within NASA and DoD space transportation development programs; competition and cooperation with foreign launch vehicle and component providers; US government limits on the conversion of long-range missiles to space launchers in the face of Russian activity in this area; and the effectiveness of Administration efforts to include the private sector in space transportation decision making. Some issues not covered in the Policy are also discussed.     

The global positioning system: policy issues for an information technology

This article, based on the executive summary of a RAND Corporation study, analyses the policy issues facing the USA in the use of its Global Positioning System (GPS), in terms of both national security and commercial applications. Foreign policy issues, including how to react to the emergence of non-US (Russian, European and Inmarsat-sponsored) alternatives to the GPS are also examined. The article concludes with a series of recommendations for policy makers. Reprinted by permission.     

Queuing theory application in imaging service analysis for small Earth observation satellites

The performance of Earth observation satellites is usually analyzed by real data or system simulation, which is accurate but not systematic. Modelling satellite service systems with queueing theory and analysing the performance statistics systematically will provide a useful guide in designing satellite systems. Earth observation satellites could be regarded as a two tandem server system with a finite buffer in between, providing two-stage service: image capture and image download service. In this paper, we introduce the queueing models for different service systems: the pure image capture service system, the two-stage service system with Poisson distribution download service, the pure download service system, and the two-stage system with general download service. Formulated solutions are given and some results are shown. From this work we can see queueing theory provides a good way to analyse the performance of small earth observation satellites, which is useful for system mission analysis and optimisation in design stage.     

Earth observation with MEO transmitters and UAS receivers: A potential utilization of Galileo constellation

Remote sensing application of Galileo upcoming constellation in the field of civil security is preliminarily analyzed, defining low resolution (25 m) and high resolution (7.5 m) working modes for a bistatic Synthetic Aperture Radar system utilizing Galileo satellites as transmitters and Unmanned Aerial Systems as receivers. Simulations offshore Somali coast and in a South Mediterranean Sea region showed that both low and high resolution acquisitions are feasible. For the low resolution mode a probability of successful image formation no matter the azimuth position of the receiving UAS has been estimated at nearly 100%. Whereas, for the high resolution mode it decreases to about 90%, which, if deemed unsatisfactory for the application, leads to the need for UAS to adapt its route to the actual Galileo satellite coverage.     

Estimation of the soil composition by IR observation of the Earth by satellites

A number of missions are in progress for Earth resources satellites to perform soil diagnosis by observing the bare soil thermal response to the heat input from the surrounding atmosphere. Heat capacity missions (and similar missions) are accomplished by measuring the soil temperature at the times of the satellite passes over the soil site.The models which are usually adopted assume that, for atmospheric conditions periodically changing during the day, the surface temperature time dependence is a function of the soil thermal inertia alone (for a dry soil).The present author has shown elsewhere that a more appropriate, two dimensional finite element modelling of the thermal behaviour of the soil, exhibits a dependence of the surface temperature time evolution on both the thermal conductivity (k) and on the volume heat capacity (?c) (for no evaporation at the interface). At least two independent temperature measurements are necessary in order to get information about k and ?c. It is shown that, within the range of values of k and ?c of the usual soils, temperature measurements taken at two successive satellite passes may yield the necessary information on the soil thermophysical properties. Charts can be constructed which will provide information on k and ?c when two soil temperatures are measured at proper times.     

Developments in Earth Observation data reception, dissemination and archival at National Remote Sensing Agency

With the rapid advancement in remote sensing technology and corresponding applications, the Earth Observation Ground Segment has undergone a significant change at NRSA. From dedicated data acquisition and processing systems, we have realized multi-mission data acquisition quick look and browse systems and also multi-mission integrated information management systems. Front end of data reception station has been upgraded to handle wider bandwidth and data rates up to 320 Mbps for near future missions such as the Radar Imaging Satellite (RISAT). Antenna, feed, down converters and RF chain have been upgraded. To cater to multi-mission scenario mission independent, fully configurable demodulator/bit synchs have been deployed. For handling data acquisition in multi-satellite scenario where in data from 5 to 6 remote sensing satellites are to be received almost simultaneously, automation of operations has been incorporated towards station configuration to avoid manual errors. From media-based data handling, there has been a shift towards net centric data handling among the various work centers such as user order processing, data processing systems, special processing systems, data quality evaluation, and product quality control work centers. The turn around time for dissemination of user desired data products has been improved from two weeks to one day. Presently a state of the art integrated environment has been envisaged which will bring down the turn around time for the supply of data products significantly. Automation has been incorporated at both data acquisition and data processing to improve the product throughput. Presently NRSA is catering to a demand of about 30,000 data products per annum and in the next two years it is aimed to reach a level of 50,000 products per annum by realizing the integrated multi-mission ground system for earth observation (IMGEOS). This will significantly modify the entire data production and dissemination chain so that data can be made available to user within 1 h from data acquisition at Shadnagar in some cases. Some of these novel developments planned in the near future will be discussed in this paper.     

Current policy issues in remote sensing: report by the International Policy Advisory Committee of ISPRS

The role of remote sensing in promoting sustainable development, its general benefits and easing access to remotely sensed images, especially for developing countries, have all been examined by the International Policy Advisory Committee of the ISPRS in 2003. This report, a slightly revised version of an article that appears in the September 2003 issue of the ISPRS's Highlights magazine, presents the committee's findings and recommendations.     

自动观测数字显示面板无数据显示的故障分析

引言西安咸阳机场自动观测系统数字面板显示设备分别安装在机场管制室和进近管制室,分DD50和WIND50两类,用于显示跑道进近着陆地带上的风向风速、跑道视程、温度、气压等气象数据,是管制人员指挥飞机的重要参考要素。     

最差用户位置算法研究与仿真分析

在计算Galileo卫星导航系统空间信号误差(SISE)、空间信号精度(SI-SA)和空间信号监测精度(SISMA)时需要用到的一个关键参数——最差用户位置(WUL)。WUL表示空间信号的轨道误差在卫星覆盖域内所导致的伪距误差最大的位置,WUL的确定可以帮助系统向用户提供正确可靠的SISA、SISMA和完好性标志(IF)等完好性信息,对提高系统的可靠性和可用性具有非常重要的意义。WUL的算法主要有两种:临界圆法和网格搜索法。详细介绍两种算法的基本原理与计算流程,比较两种算法的结果,并基于全球和区域完好性监测的概念对二者进行分析评价。     

用户动态链接库的创建与应用

动态链接库在Windows操作系统中起着重要的作用,Windows操作系统中大部分功能都是动态链接库提供的.本文介绍了如何在Visual C++中创建自己的动态链接库及在程序中的应用.