Tag Archives: imagery
By Kevin M. Kelly
A newly developed International Digital Elevation Model Service (IDEMS) is now available under the umbrella of the International Gravity Field Service (IGFS) of the International Association of Geodesy (IAG). IDEMS provides a focus for distribution of data and information about various digital elevation models, including spherical-harmonic models of Earth’s global topography and lunar and planetary DEM. Related datasets, such as representation of Inland Water within Digital Elevation Models, and relevant software which are available in the public domain are also provided. IDEMS will provide the following DEM related products:
- Compilation, tutorial-style provision and maintenance of information on global gridded DEMs
- Compilation of available national elevation data sets with information on data resolution, methods used for DEM generation and links to providers
- Generation and dissemination of spherical-harmonic models of Earth’s global topography and bathymetry
- Compilation of geodesy-relevant DEM-studies
- Extension of the focus from Earth to Moon and terrestrial planets through compilation of information on available planetary topography models
IDEMS is hosted and operated by Esri, lead by myself and Dr Jianbin Duan (Deputy Director). The new IDEMS website is available at: https://idems.maps.arcgis.com/home/index.html.
Earth Imagery at Work
Occasionally I’m disheartened when I meet someone who isn’t familiar with the term massive open online course (MOOC). But then I realize that’s a teachable moment, and I explain what MOOCs are and why they’re relevant and valuable.
MOOCs matter to GIS professionals because they help generate that content but also because they enhance participants’ geospatial skillsets while adding substance to their resumes. That’s significant value, especially in the context of today’s flagging economy.
What’s a MOOC?
A MOOC is an online course offered by a company, university, non-profit, or other provider. MOOCs are typically open to large numbers of students and are nearly always free. Those with a fee typically have a “free option” that has fewer bells and whistles.
Show me my home! The human era of GIS begins
Little more than a decade ago, seemingly the whole world snapped awake to the power of imagery of the earth from above. We began by exploring a continuous, multiscale image map of the world provided online by Google and other mapping companies. A combination of satellite and aerial photography, these pictures of Earth helped us to experience the power of imagery, and people everywhere began to experience some of what GIS practitioners already knew. We immediately zoomed in on our neighborhoods and saw locational contexts for where we reside in the world. This emerging capability allowed us to see our local communities and neighborhoods through a marvelous new microscope. Eventually, naturally, we focused beyond that first local exploration to see anywhere in the world. What resulted was a whole new way to experience and think about the world.
Initially, we zoomed in on our homes and explored our neighborhoods through this new lens. This experience transformed how people everywhere began to more fully understand their place in the world. We immediately visited other places that we knew about. Today, we continue by traveling to faraway places we want to visit. Aerial photos provide a new context from the sky and have forever changed our human perspective. This map tour visits selected areas in several communities where ultra-high-resolution imagery is available.
These simple pictures captured people’s imagination, providing whole new perspectives, and inspired new possibilities. Today, virtually anyone with Internet access can zero in on their own neighborhood to see their day-to-day world in entirely new ways. In addition, people everywhere truly appreciate the power of combining all kinds of map layers with imagery for a richer, more significant understanding.
Almost overnight, everyone with access to a computer became a GIS user.
A range of applications
By now, it’s apparent that imagery enables whole new perspectives and insights into your world and the issues you want to address. Imagery also has numerous advantages and capabilities.
Almost daily access to new information
Image collection is rapid and increasing. And access to imagery is increasingly becoming more responsive. Many satellites and sensors are already deployed with more coming all the time, collecting new data, adding to a continuous collection effort—a time series of observations about our planet. These image collections are enabling us to map, measure, and monitor virtually everything on or near the earth’s surface. All of us can quite rapidly gather much of the data that we need for our work. Imagery has become our primary method for exploration when we “travel” to other planets and beyond. We send probes into space and receive returns primarily in the form of imagery that provides a continuous time series of information observations. And it enables us to derive new information in many interesting ways.
Looking back in time
The use of aerial imagery is still relatively young. While imagery only began to be used in the twentieth century, it is easy to compare observations for existing points in time that reside in our imagery collections. In addition, we can overlay imagery with historical maps, enabling us to compare the past with the present.
Imagery data collections are becoming richer every day
Imagery is creating an explosion of discovery. Many imagery initiatives are repetitive and growing, expanding and adding to image databases for our areas of interest. ArcGIS is scaling out, enabling the management of increasingly large, dynamically growing earth observations. This points to the immediacy of imagery and its capacity for easy integration, enabling all kinds of new applications and opportunities for use—things like before-and-after views for disaster response, rapid exploitation of newly collected imagery, image interpretation and classification, and the ability to derive intelligence. Over time, many of these techniques will grow in interesting new ways, enabling deeper learning about our communities, the problems and issues we face, and how we can use GIS to address these.
Imagery enables powerful analytic capabilities
Imagery and its general raster format enable rich analysis using ArcGIS. And, in turn, these enable more meaningful insights and perspectives about the problems we want to address.
This post is excerpted from The ArcGIS Imagery Book: New View, New Vision. Imagery is suddenly a big deal, and those who are adept at finding it, analyzing it, and understanding what it actually means are going to be in demand in the years ahead. The purpose of this book is to help everyone from GIS professionals to app developers, and web designers to virtually anyone how to become smarter, more skillful, and more powerful appliers of image data. The book is available through Amazon.com and other booksellers, and is also available at http://www.TheArcGISImageryBook.com for free.
Exciting news from the Arctic! Version 2 of the Arctic DEM has been released. Topographic elevation of the Arctic can now be viewed and analyzed like never before. This release extends the detailed 2 meter Alaska elevation data with additional 2m data for Novaya Zemlya and Franz Josef Land, as well as preliminary 8 meter data for the entire Arctic. Additional detailed 2 meter elevation data will be released in quarterly installments over 2017 until the arctic data is complete. This is the result of a partnership between Esri, the National Geospatial Intelligence Agency, the National Science Foundation, and the Polar Geospatial Center at the University of Minnesota.
In September 2016, the White House hosted an Arctic Ministerial meeting, with over 20 countries represented, where this data was showcased and new commitments on data provisions were sought. The goal of the meeting and the function of the new data is to help people better understand, adapt to, and address the changing conditions in the Arctic.
The four key themes include:
- Understanding Arctic-Science Challenges and their Regional and Global Implications.
- Strengthening and Integrating Arctic Observations and Data Sharing.
- Applying Expanded Scientific Understanding of the Arctic to Build Regional Resilience and Shape Global Responses.
- Using Arctic Science as a Vehicle for Science, Technology, Engineering, and Math (STEM) Education and Citizen Empowerment.
Putting remotely sensed image data to work
Imagery provides more than just plain pictures. Some sensors detect energy beyond what is humanly visible, allowing us to “see” across broad swaths of the electromagnetic spectrum. This enables scientists, geologists, farmers, botanists, and other specialists to examine conditions, events, and activities that would otherwise be hidden. The implications are profound and the applications are seemingly endless.
Expanding your point of view
Every day, the earth is directly imaged from scores of sensors in the sky and from orbit in space. Almost everything that happens is measured, monitored, photographed, and explored by thousands of imaging devices mounted on satellites, aircraft, drones, and robots. Much of this information ends up as imagery that is integrated into a large living, virtual GIS of the world, deployed on the web.
Some of these sensors see beyond what our eyes see, enabling us to view what’s not apparent. Multispectral imagery measures and captures this information about a world that has many more dimensions than just the colors of the rainbow—it sees past the limits of what our eyes perceive.
by Jyotika I. Virmani, Senior Director of Energy and Environment for XPRIZE and Dawn Wright, Esri Chief Scientist
Over 60% of the Earth’s surface has not yet been mapped. The ocean covers 70% of our planet’s landmass, and of that, less than 15% of the sea floor has been mapped at a resolution greater than 5 km. In fact, we have higher resolution maps of the entire surface of the Moon, Venus, and Mars than we do of our own Earth. But this situation can be changed. We are in the midst of a Technological Revolution and with the advent of exponential technologies such as 3D printing, Robotics, Artificial Intelligence, and Virtual Reality, we now have smaller and cheaper tools and greater access to information.
Mapping the sea floor has, historically, been a challenge. Seawater is obviously opaque, which prevents us from using visible, remote surveying techniques to get maps of the sea floor. Seawater is a harsh and corrosive medium and, with a viscosity greater than air, it has additional engineering challenges such as high friction resulting in rapid power drain for any device that is used to map the bathymetry underwater. It is also expensive to access because the technology of today requires ships to sail to the area being mapped before the mapping technology is deployed. At an average cost of $60,000 a day, it can easily cost a few hundred thousand dollars before mapping can even begin.
The Shell Ocean Discovery XPRIZE, a 3-year competition launched last December, is incentivizing innovators to develop the autonomous underwater robots we need to map the sea floor at 5m or higher resolution and take high-definition images of the deep sea. Within this is a $1 million National Oceanic and Atmospheric Administration (NOAA) Bonus Prize, for teams who can develop an underwater tracking device that can autonomously track a biological or chemical to its source. The devices will be shore-based or aerial deployments, removing the massive costs associated with ships. The competition will conclude in December 2018 and, like all other XPRIZE competitions, there will be a number of technical solutions that emerge to provide underwater cartographers the tools they need to survey the sea floor.
The Arctic environment is a leading indicator of climate change. The shifts that will eventually affect the entire globe are among the most visible there. A comprehensive understanding of the shifts occurring in this area are crucial now more than ever.
Traditional imagery of the Arctic was collected via aircraft, but is very limited due to the inhospitable and remote nature of the polar region. Now 3-D digital elevation models (DEMs) of the entire Arctic are scheduled for release by 2017. With a resolution of 2 m, these new DEMs are over one hundred times higher resolution than what has previously been available for the entire Arctic. This has been made possible through a unique public private partnership between Esri, the White House and several important partners by way of DigitalGlobe satellite imagery.
Today the first of these rich elevation models covering the State of Alaska is being released. They are the first deliverable of the ArcticDEM project, created after a January 2015 Presidential Executive Order calling for enhanced coordination of national efforts in the Arctic. Climate Change is one of the biggest threats we face, it is being driven by human activity, and it is disrupting Americans’ lives right now. President Barack Obama spoke about the project at an Arctic conference in Kotzebue, Alaska on September 3, 2015 and called for action to reverse the trend of climate change, an exponentially growing problem for the entire planet.
Information gathered from a distance
Remote sensing—the acquisition of information from a distance—has had a profound impact on human affairs in modern history. This image of British Beach (the WWII code name for one landing spot of the June 1944 Normandy invasion) taken from a specially equipped US Army F5, reveals rifle troops on the beach coming in from various large and small landing craft. Seven decades later—even as its application has expanded to unimaginable reaches—remote sensing remains the most significant of reconnaissance and earth observation technologies.
Many platforms, many applications
Modern imagery is captured from a broad range of altitudes starting from ground level to over 22,000 miles above earth. The images that come from each altitude offer distinct advantages for each application. While not meant to be an exhaustive inventory, let’s take a look at some of the most commonly used sensor altitudes.
Humans have always sought the high vantage point above the landscape. Throughout history, whether from a treetop or a mountain peak or a rocky cliff, the view from above allowed our ancestors to answer important questions: Where is there water? Where is the best hunting ground? Where are my enemies? Aerial photography was first practiced by balloonist Gaspard-Félix Tournachon in 1858 over Paris. With the advent of both photography and practical air flight in the early twentieth century, the advantages of having the high ground led to a quantum shift forward and the field of remote sensing was born.
The technology came of age rapidly during World War I as a superior new military capability. From 1914 to 1918, aerial reconnaissance evolved from basically nothing to a rigorous, complex science. Many of the remote sensing procedures, methods, and terminology still in use today had their origins in this period. Throughout World War II the science and accuracy of remote sensing increased.
There may be hundreds of thousands, if not millions, of undiscovered ancient sites across the globe, and Sarah Parcak wants to locate them. As a satellite archaeologist, she analyzes infrared imagery collected from far above the earth’s surface and identify subtle changes that signal a man-made presence hidden from view. Doing so, she and her colleagues aim to make invisible history visible once again—and to offer a new understanding of the past.