December 13

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Contents

Editor's Introduction

This week I report on Digital Globe's ImageConnect service, which I tested, and highlight four books from ESRI Press. Plus, 15 press releases.

— Matteo Luccio

Downloading DigitalGlobe Imagery with ImageConnect

For many purposes, it is not enough to view satellite and aerial imagery in Google Earth, Virtual Earth, or World Wind — you need to download it to your own GIS. The ImageConnect Web map service allows users to download high resolution images from DigitalGlobe's library directly into ArcGIS, MapInfo, and AutoCAD Map 3D. This week, Digital Globe promoted the service by offering a free trial, so I checked it out, using ArcGIS.

First I had to download and install a plug-in from Digital Globe (the free trial offer, which ended on Wednesday, provided a link to the download page, a client ID, and a license code). Then I opened ArcMap and an ImageConnect drop-down menu appeared. Next, I connected to ESRI's Geography Network and downloaded the ESRI_World layer. I was now ready to navigate to any spot on our planet and download imagery.

ImageConnect sends coordinates from the map view in your mapping software to a GlobeXplorer DLL, which then formulates a URL and sends it over the Internet to the GlobeXplorer Image server. After validating your client ID, the server evaluates the coordinates, projects the image into the requested projection, and sends it back to you. The DLL then creates a world file based upon the image header information.

From any extent, I could select "Download a premium image" from the ImageConnect drop-down menu and the system would automatically select the most recent image for that extent. If I had "Dynamic Download" selected in the properties, every time I zoomed in or out ImageConnect generated a new image to fill my screen. ImageConnect gives you the choice to keep previous layers or to overwrite them. If you choose to keep them, they will be added to your active layers.

While the "ImageConnect" button will download an image to fit your screen resolution, the image's actual ground resolution (meters per pixel) will depend on the scale that you are using when you request the image. When you check "Dynamic Download," every time you pan, zoom, change the projection or update any of the map elements, the system automatically retrieves new images. To speed things up when navigating to points far apart from each other, I turned this option off.

If you select "Download a premium image" from the ImageConnect drop-down menu, the system downloads an image large enough to fill your screen and appropriate for your current scale. In ArcGIS, the first image you request will appear at the bottom of your table of contents. Any visible polygon features listed above the image are layered over it and may hide it; to see it, you simply drag the image layer on top of any polygon layers or remove the fill from the polygon symbols.

If you select "ImageConnect Data Library" from the drop-down menu, a table will appear, listing the imagery available at the scale and area in your current view. The default selection that you would download by selecting "Download a premium image" is checked. You can uncheck that selection and choose another dataset instead. (However, GlobeXplorer mosaics imagery together at seams, so selecting any one dataset may not fill your view completely.) Any area not covered will be black.

Each image you download is accompanied by a text file containing the raw metadata from the GlobeXplorer server, including:

• the name of the original provider of the dataset (data source);
• the date when the image was taken (if the imagery was taken over a range of days or weeks due to weather, the oldest date for that dataset is shown);
• the resolution (the maximum ground sampling distance of the original dataset in meters per pixel; however, the actual resolution downloaded is determined by the scale that you are using when you request the image);
• the spatial accuracy (defined using the National Mapping Accuracy Standards); and
• the spectrum of the imagery (such as color, panchromatic, or color infrared).

GlobeXplorer also provides an FGDC metadata record in XML format.

If you need to create high resolution prints or retrieve a single large image to cover an area, the drop-down menu also allows you to download a custom-size image at a specified scale, up to a maximum of 5,000 x 5,000 pixels. According to the manual, extremely large images may take up to 15 minutes to generate and begin downloading. However, in my test, over a cable Internet connection, images never took more than ten seconds to download. The custom image size option allows you to see a thumbnail preview of your image, in a separate window. While this is not a full-sized representation of the image, it will allow you to preview its color tone and extent.

The default setting for custom images is "fill this view," which returns images that exactly fill the mapping window. Alternatively, if you need to draw images that cover larger areas at exact scales, you may set the scale of the data or specify the number of pixels for the image width or height and the software will automatically set the remaining options so as to completely fill your view. However, there is a limit to the size of an image that you can draw from the GlobeXplorer server at any one time.

You can also draw a custom image at an exact scale and/or pixel size, centered on the center of your view. This option allows you to set your own scale, image width, and image height in pixels, within the maximum file size allowed by the server.

In addition to the "predefined" projections available by default, GlobeXplorer now also supports many custom projections. If you use this option to define your own custom projection, ImageConnect will send your parameters to its servers, which will then re-project the imagery to your coordinate system.

Four Books from ESRI Press

As the year draws to a close, here are four books that ESRI Press published in 2007.

GIS for Homeland Security, by Mike Kataoka

Another in the ESRI Press series "Case studies in GIS," this very practical book presents 15 brief case studies that illustrate how GIS functions behind the scenes to help fight wildfires, deal with explosions, and monitor terrorism, crime, and the spread of disease. The six short chapters cover all the key phases of emergency management and response: gathering and analyzing intelligence, protecting critical infrastructure, responding to complex emergencies, preparing for disease outbreaks and bioterrorism, and securing complex events.

Building on the lessons of 9/11 and Hurricane Katrina — which, Kataoka writes, "have validated GIS as the technology of choice when seconds count and lives and property are at risk" — the book examines the gaps in coordination among bureaucracies with overlapping mandates and jurisdictions. It also points out such significant challenges as some agencies' reluctance to share data for fear of compromising their individual security. However, for the most part, GIS for Homeland Security focuses on the positive trends and the emerging "best practices" developed by government agencies and private entities tasked with emergency response. Much emphasis is on the ways in which planning and preparedness can prevent some catastrophes and mitigate the effects of other ones.

Kataoka, an ESRI Press editor and former journalist, writes in nontechnical language for a wide audience of government decision makers and first responders. One case study shows how the Arizona Counter Terrorism Information Center, the state's analysis hub for crime- and terrorism-related intelligence, relies on a data fusion system powered by ESRI's ArcGIS software and MetaCarta's Geographic Text Search. The system uses geography as a filter when searching through text documents — including news articles, e-mails, and Web pages.

The book also profiles four GIS professionals who have put the technology "to the test, under difficult, even dangerous circumstances." Among them is Ron Langhelm of the Federal Emergency Management Agency (FEMA), who has used his GIS expertise to support recovery operations after earthquakes, hurricanes, and the September 11, 2001, attacks on the World Trade Center in New York City.

The final chapter, on looking ahead, discusses a federal initiative, the National Spatial Data Infrastructure, and, in particular, the National Map. An eight-page glossary of acronyms and abbreviations and a 17-page glossary of homeland security terms complete this slender but useful book.

Research and Theory in Advancing Spatial Data Infrastructure Concepts, edited by Harlan Onsrud

In this densely-packed, 293-page scholarly book, nearly 50 experts from around the world present the latest research in the development of spatial data infrastructures (SDIs), which serve as the framework for efficiently exchanging, using, and managing spatial data. SDIs include geographic data, metadata, technology, services, standards, and partnerships that must be in place for the system to work smoothly.

In addition to describing the importance and benefits of SDIs, the authors tackle the technical, legal, economic, and institutional challenges faced by those who build them. The articles collected in this tome were first presented at the 2006 conference of the Global Spatial Data Infrastructure Association, held in Santiago, Chile. The topics covered include data sharing partnerships among government jurisdictions, plans under way to create the Infrastructure for Spatial Information in Europe (INSPIRE), national clearinghouses for spatial data, and models for planning, financing, and implementing SDI initiatives. The authors analyze each of these initiatives in detail and evaluate the extent to which they contribute to national economic competitiveness and social well-being.

These scholars also tackle some of the challenges of implementing SDIs, including the impacts of government fees for, and restrictions on, geospatial data. The last articles in the book stress the importance of SDIs in providing the data needed to fight poverty and help prepare for and recover from national disasters.

The book's editor, Harlan J. Onsrud, is a professor in the Department of Spatial Information Science and Engineering at the University of Maine and a research scientist with the National Center for Geographic Information and Analysis. He is past president of the Global Spatial Data Infrastructure Association and the University Consortium for Geographic Information Science.

This is a highly technical book for academics and GIS practitioners, illustrated solely with tables, charts, and diagrams. Hopefully, however, much of the content of these studies will percolate into the broader trade publications.

Empowering Electric and Gas Utilities with GIS, by Bill Meehan

Delivering the electricity and gas that keep homes comfortable, factories running, and cities illuminated entails enormous responsibilities to customers, shareholders, employees, the government, and the environment. GIS is the ideal tool to help utility companies meet their mission and manage their widely distributed assets. Yet, many still do not benefit from such an enterprise view and some still see GIS strictly as a way of making maps. "They may be making incremental improvements in the operations but are missing greater opportunities," writes Bill Meehan, P.E., ESRI's director of worldwide utility industry solutions and former vice president of electric operations at NSTAR, Massachusetts' largest investor-owned electric and gas utility.

"Utilities are awakening to the dramatic impact a GIS can have on their overall operations," says Meehan, who provides three dozen examples of the multifarious ways in which utilities from Burbank, California, to Beirut, Lebanon, use geospatial technology.

While utilities typically turn to GIS to map a network such as the company's electric lines or gas pipelines, the technology, Meehan argues, goes far beyond that to include processing work orders in a timely fashion and quickly spotting trouble, such as the location of downed power lines or gas leaks.

In addition to his real-world examples, Meehan uses a fictional utility, AnyTown Energy, to illustrate how GIS can improve customer service, lower costs, locate / prevent outages, restore power and gas, manage assets, conduct planning, locate new plants, and improve logistics. He concludes the book with a detailed business case for an enterprise GIS for AnyTown Energy that would improve the utility's performance and benefit customers, shareholders, employees, and management. The book also provides a template for those already working with GIS who want to expand its use.

Many screenshots from proprietary, specialized GIS software complete this book, another in ESRI Press' "Case studies in GIS" series. It is aimed at utility executives and managers — especially electric and gas line operational managers, who can apply the insights to their own business problems — as well as GIS professionals who are seeking opportunities in the gas and electric business. Finally, the book is also for chief information officers, chief technology officers, and information technology managers — so that they may better understand the problems facing utility operations people and how geospatial technology can improve operations.

Understanding Place: GIS and Mapping across the Curriculum, by Diana Stuart Sinton and Jennifer J. Lund

"Each case study in this volume describes how an experienced instructor has used GIS in the service of his or her own teaching, within traditions of a classical undergraduate education," write Sinton and Lund, who edited the book and wrote a few of its chapters. "Authors describe how they integrated mapping software into their syllabi as they pursued the learning goals of their discipline and worked to create a realistic learning environment in which students practice inquiry in their field."

The book's 19 chapters span the natural sciences, social sciences, arts, and humanities. When students use GIS and mapping to augment their studies, the authors argue, "they see more, understand more, and engage more deeply with the subject matter." Empowered to pursue their own questions, they often investigate important local issues — thereby both learning and making valuable contributions to their communities.

At the heart of this book, of course, is the authors' profound conviction — validated by many years of teaching — that spatial thinking is a cognitive skill as important as logical or quantitative thinking. The first section of the book takes a pedagogical approach, describing the role of maps and GIS in teaching important skills: thinking with visual evidence, thinking spatially, creating narratives, reasoning with quantities, and collaborating with communities. Sinton and Lund address overall teaching goals and describe in detail how to incorporate maps and GIS into class work and assignments. They use Sir Francis Drake's perilous voyage in the 1500s to show how tables of information — such as the captain's logs and historical data — can be analyzed and mapped to quickly show where the fleet of ships ran into trouble and why. This helps students, the authors argue, "find drama in data."

The bulk of the book consists of case studies that testify to the broad relevance of mapping to all academic disciplines. Chapters, which are organized by discipline, can be read in any order. However, a topical cross-reference at the back of the book helps instructors across all the disciplines find the case studies that are most relevant to theirs.

What I find most useful and interesting about this book is the wide variety of voices, disciplines, and methods it presents, while maintaining a coherent focus on the role of maps and GIS in enhancing a university education.

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