The development of standards based systems support the processing, archiving, management and distribution of spatial data. These benefits are particularly important in the field of earth observation which involves the capture of data from hundreds of different types of sensors and thousands of different distribution products. Editors Liping Di and H.K. Ramapriyan provide a collection of material from leading international sources on the topic of standards based systems for earth observation as part of the Lecture Notes in Geoinformation and Cartography series from Springer publishers.
Review by Jeff Thurston
Standardisation is integral for the geoinformation industry to succeed. It enables both people and technology to work together through shared resources, common understanding and increased connectivity. The value of this collaborative growth has significant economic impact on local, national and international government and business. It also supports strong, effective scientific pursuits, often allowing greater access to a myriad of scientific data, geo-processing facilities and software as well as improved distribution of results more quickly and broadly.
The book Standard-Based Data and Information Systems for Earth Observation is part of the Springer publishing series Lecture Notes in Geoinformation and Cartography. The book contains thirteen chapters that describe developments in the area of standards and is oriented toward earth observation systems – primarily satellite based information capture, management and distribution systems.
Edited by Liping Di and H.K. Ramapriyan the book includes presentation and discussion on numerous topics by several leading authors involved in standards based work. It also addresses new developments in service oriented architectures (SOA) based geospatial knowledge systems. Algorithms, distributed image mining, architectures, prototypes and knowledge representation is included. The term Spatial Information Grid (SIG) is expressed as the fundamental structure for sharing and interoperation of distributed geospatial data. The underlying theory throughout this book is that data access and analysis tools across numerous disciplines depend upon the reduction of barriers to data access and use.
One will want to keep a list of acronyms close by while reading this book as it is filled with them. Nevertheless, this is the result of so many earth observation systems operating and or archiving geoinformation. For example, NASA’s Earth Observing System (EOS) Data and Information System (EOSDIS) at the end of 2007 held over 3.7 pentabytes of data from 90 instruments including more than 2000 operating projects – alone. Solving the distribution issues of 4 terabytes of geoinformation per day is no simple task. Couple this to other services and the magnitude of computing becomes difficult to embrace, without standards management.
As author D. Zhang points out in the opening chapter, SIG aatempts to process large amounts of data, includes high performance computing, involves sharing management, must involve legacy systems, includes collaboration, supports heterogenous systems and will necessarily need to adapt to changing circumstances. Collectively SIG will include 4 layers – resources, share, assembly and distribution.
We find continual reference to standards throughout the book, often including Open Geospatial Consortium (OGC) specifications. While this book is primarily oriented to earth observation systems and programs of the United States, although the concepts apply elsewhere. Having said that this book contains an excellent overview of U.S. earth imaging programs and services, easily one of the best I have read in terms of completeness as it also explains how the various imaging branches of the U.S. government come together and are designed to work together. Readers will learn how map servers, catalog servers, coverage servers and associated clients come together and interoperate.
This book is important for it’s ability to not only describe the operating technologies and programs for earth observation, but it also attempts to explain how science depends upon particular types of geodata, often collected in unique ways. It causes the reader to appreciate the task of combining these disparate pieces of geodata into seamless systems with easy-to-access interfaces while maintaining the descriptive documentation and metadata associated with them.
The editors attempt to include how current earth observation programs came to exist as they currently operate and some of the history and developments leading up to their current status and the all important ‘why’ certain routes were chosen. I found this background interesting, and it caused me to understand that earth observation within the U.S. is far more organised (and considered) than I might have earlier appreciated.
The level of diversity in terms of scientific tools, sensors and processing methods, often determined by discipline, provides a glimpse into complexity and vastness of the U.S. earth observation holdings. In the ocean and meteorological communities, for example, the Open-source Project for a Network Data Access Protocol (OPenDAP) is an integral component for working with these types of data. This free software can also be quickly downloaded. Most OPenDAP resources can be served through the use of OGC specifications.
Through reviewing this book I’ve come away with the conclusion that the U.S. earth data management systems have evolved through to a next-generation level of operating over the last 3 years with several key changes in operating coming together. I am not certain many people in the geospatial community know of these changes or appreciate them yet, although they are putting resources into the open marketplace that simply were not there 5 years ago. Standards have made this possible. NASA’s Data Integration Gateway essentially descibes this transition and development.
George Percivall of OGC writes on the development of standard arising within that organisations. The descriptions connect the work of that organisation including web map services, web feature services, web service coverage, catalogue services, sensor observation services and many others. He points to the benfits of reducing costs through standards, shorten itme to markets, opportunities to enter new markets, forum for sharing with others, quicker delivery and the ability to mobilize products with better connectivity.
NASA’s EOS is research driven and satellites provide ‘standard products’ suitable to a wide number of scientists. An explanation of the Distributed Active Archive Centers (DAACS) is included and readers can learn about the many NASA programs such as the Tropical Rainfall Measuring Mission (TRMM) among many others. In the U.S. the concept of Science Investigator-led Processing Systems (SIPs) is outlined and explained.
Several satellite missions including TERRA, JASON, CloudSAT, AURA, AQUA, QuickSCAT and others are included and described. The graphics in the book support these descriptions well and often provide details linking them to processes so viewers can see where and how they overlap and which mission might hold the resources they are considering data services for. In principle EOSDIS is diivided between Mission Systems and Science Systems with various missions transcending the division.The discussion of EOSDIS in this book is the best I have read for it’s completeness.
Also included are details about data standards and conventions in use. GRIdded Binary (GRIB) and netCDF format evolution and use is outlined. Metadata Catalogs and the role and links to the U.S. Federal Geographic Data Committee (FGDC) are discussed. Marine applications and interoperability are highlighted throughout the book. These are also explained in terms of OGC work in the Oceans Interoperability Experiment, designed to link ocean sensors through the Sensor Web Enablement (SWE) program, for example.
This book also explains how to involve producers of geoinformation into providing standard-based information for use in larger networks through realizing the benefits often connected to machine interfaces for coding, management and retrieval of their resources. Catalogue services for archiving geoinformation are discussed and it is pointed out that just because something is stored today that it may not be accessible later unless it is maintained through different versions of software and or hardware changes.Management for these adaptations is included along with considerations.
Many people may not realise it but the entire U.S. earth observation framework changed to a Linux distributed operating system and that change was completed only recently. The financial gains through this implementation have been used to enhance delivery of products, often at 4x’s the amount previously. Many issues relating to speed of delivery have been overcome and a significant amount of products are retained on-demand.
If you are involved in earth observation then this book is required reading I think. Although it is focused upon U.S. earth observation programs and the framework for management and delivery of products within that country, the principles are universal and can be applied elsewhere. I would really like to see this work extended to private industry services and operation for other agencies like the European Space Agency (ESA) – who have similar complex earth observation programs.
The editors have managed to pull together leading edge developments pertaining to standards-based geoinformation for earth observation within this book. They succeed in helping readers to understand how all these EO programs we hear about do come together. Importantly they include details about the evolution of programs and how they evolved and why they changed to exist in current forms.
Standards-Based Data and Information Systems for Earth Observation does exactly what is intended. It provides an excellent overview of current standards based developements in earth observation. It specifically details the benefits that standardisation supports and enables with a view to earth imaging and geoinformation. The book explains the connection of science to these mission programs and some of the logic behind choices made over time and why funding them has been important. This work will provide insight into many products and services that have only recently become available to the general public and scientists, that include vast quanitities of highly valuable and useful earth observation data. It is fair to say that Open Geospatial Consortium (OGC) is enabling many of the deliverables through standardised interfaces.
————————————————————————–
Jeff Thurston is co-founder and co-editor of V1 Magazine for Vector1 Media. He is based in Berlin.
