The Power and Synergy of Imagery and GIS

January 31, 2025

Russell G. Congalton

Black-and-white analog aerial photo of University of New Hampshire campus; Courtesy: Eastern Topographics, Wolfboro, NH — This photo is a black and white, analog aerial photograph of the University of New Hampshire campus taken on April 14, 2014. Courtesy Eastern Topographics, Wolfboro, NH

In the beginning there was the aerial photograph. Initially, only in black and white, but soon along came color to really brighten things up. So much information could be gleaned from these photographs without having to travel to sites yourself. Not only could a viewer tell what the current conditions of the area were, but they could compare the area to previous photos and see what changed. Then color infrared film was invented, giving us the ability to see in a wavelength of electromagnetic energy beyond what our eyes could see. The possibilities were endless. Applications included urban planning, crop monitoring, forest characterization, water quality analysis, and disaster relief among many others.

While photographs taken with film were very powerful, images acquired digitally using a sensor system or a camera were even more so. Satellites were launched that imaged the earth repeatedly and regularly. Initially, these images did not have the same amount of detail (spatial resolution) as the analog photographs, but that quickly changed, and today film is all but obsolete. In addition, these digital sensors have the ability to record in wavelengths beyond what our eyes can see including near infrared, middle infrared, and thermal.

This figure demonstrates one of the powerful abilities of a GIS to overlay various data layers (many generated from remote sensing) to ask questions such as the optimal place to put in a new parking lot on the University of New Hampshire campus. Courtesy Russell G. Congalton

Having a steady source of information generated from remotely sensed imagery about our planet is invaluable. However, could this information be improved? The answer is yes; through geographic information systems (GIS). A GIS allows the user to put together various sources of information by layering the data layers on top of each other to tease out even more information and help in the decision-making process. (Insert image 2 overlay analysis example near here) For example, a university planner may want to determine the best place to build a new campus parking lot. They might download a general land cover/vegetation map (National Land Cover Data from the USGS) that was created from Landsat imagery. Then they might obtain a slope and aspect data layer (also from the USGS generated from remotely sensed imagery). A map of soil types (especially hydric or wetland soils) could be gotten from the Natural Resource Conservation Service (this information was also generated from remote sensing). Finally, the university probably already has a detailed campus map with building footprints and other infrastructure (utilities, pipelines, roads, etc.). An analyst could then use a GIS overlay all these various data sets on top of each other to determine the best candidate locations to build the new parking lot. The decision-makers could specify the criteria they want for the new parking lot. For example, they could say that they want the lot placed on relatively flat land, within 10 minutes walking distance of the central campus, near a central access road, not on a wetland, and where no forest land needed to be disturbed. The GIS could perform this analysis digitally and provide potential locations that meet these criteria. The decision-makers could, if they chose, revise their criteria and quickly get a different set of potential locations.

Clearly, GIS is a powerful tool that has become ubiquitous in our society. Farmers, business developers, politicians, law enforcement, natural resource managers, emergency management agencies, real estate agents, community planners and almost everyone else either uses a GIS or the information generated from one. However, it is important to not lose sight of the source of the vast majority of information input into the GIS. Imagery/remote sensing is the source of many of our GIS data layers. Therefore, a GIS analyst should be aware of the basics of remote sensing so that they not only have an appreciation of how the layers are created, but also so that some evaluation of data quality or accuracy is possible. There is an old adage that is appropriate here; garbage in means garbage out (GIGO). If the GIS user is either unaware of how the data they are using has been created or is using that data in an incorrect/inappropriate manner, then the decisions made with that data could be seriously flawed.

The synergy between imagery/remote sensing and GIS is obvious and undeniable. GIS is highly dependent on having timely and accurate data layers (most generated from remote sensing) to produce effective decisions. The GIS analyst is responsible for choosing the most accurate and appropriate data layers to conduct their analysis and solve their problem. The more informed they are about how remote sensing/imagery were used to create the data layers, the better the decisions made with that data.

Corn varieties noted on aerial map; Credit: Russell G. Congalton — This graphic shows an image acquired by an Unpiloted Aerial System (UAS) that is part of an ongoing research study to evaluate the health of different varieties of corn planted on the University of New Hampshire farms. The BMR (Brown Mid Rim) corn produces more biomass for feeding cows, but is more susceptible to disease. The initial results of the study demonstrated our ability to identify BMR corn vs. other varieties. Courtesy Russell G. Congalton

Analog remote sensing (aerial photography) since the 1950s, digital imagery and analysis since the 1970s, and GIS since the mid 1980s have developed and improved over time. Since the turn of the last century, these tools have exploded in their usefulness and capabilities.

The number of countries and private companies collecting and distributing remotely sensed imagery has grown exponentially with increased spatial, spectral, temporal, and radiometric resolution such that imagery almost anywhere on our planet is readily available at almost any time. Computers have improved and software has been developed for not only processing the remotely sensed imagery, but also for conducting more effective and efficient geospatial analysis. The future looks very bright with the recent progress in artificial intelligence and deep learning that will enable us to generate better information from the remotely sensed imagery which can then be used in GIS to more efficiently and effectively investigate and understand our modern-day problems and issues. Therefore, it is time for the enlightened geospatial analyst to not only be knowledgeable about geographic information systems and science, but to know at least the basics of imagery and the science of remote sensing.

There are many ways for you to accept this challenge and learn the basics or more about remote sensing. It is fine to start slowly and find some introductory tutorials on such sources as youtube.com, americaview.org, usgs.gov or just type “remote sensing” into your favorite search engine. Once you get going, there are also short courses, workshops, and other lectures that you can sign up to take and books that you can purchase that can teach you more. Finally, there are courses and even certificates and degrees offered at many colleges and universities around the world. The time is now to make use of the synergies between remote sensing and GIS and the geospatial analyst of the future will have skills and knowledge of both!

Russell G. Congalton is associate chair and professor of Remote Sensing and GIS in the Department of Natural Resources and the Environment at the University of New Hampshire. He has over 40 years of teaching and research experience, first at the University of California, Berkeley and now at UNH. He teaches numerous courses in geospatial analysis and has authored or coauthored more than 120 peer-reviewed papers, more than 120 conference proceedings, and fifteen book chapters. He is the co-editor of Quantifying Spatial Uncertainty in Natural Resources: Theory and Applications for GIS and Remote Sensing, and co-author of five books, including Assessing the Accuracy of Remotely Sensed Data: Principles and Practices (1st, 2nd, and 3rd editions, CRC Press); and Imagery and GIS: Best Practices for Extracting Information from Imagery (Esri 2017). Among his many honors, he was elected a Fellow in 2007 and an Honorary Member/Lifetime Achievement in 2016 of the American Society for Photogrammetry and Remote Sensing (ASPRS). He was also presented with a Lifetime Achievement Award by AmericaView in 2022 and the Pecora Award by the USGS and NASA in 2023.

Featured Articles is a special section of the AAG Newsletter where AAG sponsors highlight recent programs and activities of significance to geographers and members of the AAG. To sponsor the AAG and submit an article, please contact meeting@aag.org.

News

AAG Welcomes Spring 2025 Interns

January 23, 2025

Two new interns have joined the AAG staff this spring. The AAG would like to welcome Laura Conway and Sean Yates to the organization.

Laura Conway is currently in the final stages of receiving her GIS Certificate and AAS in Wildlife Management and Conservation from Austin Community College in Austin, Texas. Currently working as a field technician for Bat Conservation International, she sees the internship with AAG to be the perfect addition to rounding out her educational experience before moving on to pursue her BS in Rangeland Ecology. Laura is passionate about spatial ecology and translocation, two fields that strongly connect conservation, geology, advocacy and policy. When she’s not working in caves, she’s enjoying them in her free time or learning a new craft like felting or puppetry. She and her red heeler, Oddy, can also be found outside, swimming or birding.

Our Media and Science Communication intern is Sean Yates, a sophomore at the University of Georgia double-majoring in Ecology and Geography. Sean is also pursuing a minor in Environmental Law and certificate programs in Sustainability, GIS, and Urban & Metropolitan Studies, hoping to apply his keen interests to a future in sustainable urban development or natural resource management. When not at school or work, Sean enjoys hiking, going to concerts, and watching Atlanta sports. Additionally, he is a big advocate for community service projects and currently volunteers with Athens-Clarke County as a Trail Ambassador on the weekends. Sean is passionate about the geography of the world and has made it a personal goal to visit every national park in the United States.

If you or someone you know is interested in applying for an internship at the AAG, the AAG seeks interns on a year-round basis. More information on internships at the AAG is also available on the Jobs & Careers section of the AAG website at https://www.aag.org/about-us/#internships.

Edward Babin

Dr. Edward Babin, a long-time professor at the University of South Carolina, Upstate (USC), died Sunday, March 5, 2023, in Spartanburg, SC.

He received his B.A. degree from the University of Louisiana, Lafayette in 1965, a master’s degree in Geography from the University of Arkansas in 1967, and a Ph.D. in Geography from the University of Georgia in 1974.

He taught geography at the University of Louisiana, Lafayette from 1968 to 1973. Dr. Babin joined USC Upstate as Professor of Geography from 1974 to 2015. He served as chair of the department twice.

Ed was born on August 29, 1944, the only child of Clarence and Helen Ourso Babin in Donaldsonville, LA.

Ed married Joanne Tinie Walsh on March 18, 1989, at Jesus, Our Risen Savior Catholic Church and was her devoted husband. They had no children. After marrying, Ed and Joanne became members of St. Paul the Apostle Catholic Church where Ed was an usher there for many years. He greeted parishioners at the door at both daily and Sunday Masses and enjoyed this ministry more than any other service he performed in the church.

In about 2013, Ed also started the senior singles’ luncheon for parishioners who found themselves single for one reason or another. This became a great place for newcomers to the parish to meet longtime members.

Ed became a professed member of the Secular Franciscan Order on April 5, 1995, which was a lifetime commitment to an international lay religious order in the Roman Catholic Church. He was a member of the St. Michael the Archangel Fraternity and served as its first minister for two terms.

Ed was an avid reader on many geographical topics and loved to discuss these with others. He had a dry sense of humor and a quick wit and loved to tell jokes and stories. He loved pets and had many special dogs and two cats in his lifetime. Among the dogs were Angel, Pepita, and Pixie, whom he loved to walk with through the neighborhood and greet the neighbors.

He grew tomatoes in his garden for many years and gave away tomatoes to others generously. He did his own yard work and earned “Yard of the Month” in the Forest Hills Neighborhood Association several times.

In addition to his wife, Joanne, Edward is survived by his cousins, Jay Landry (Verlein) of Donaldsonville, LA, and “Sport” Le Blanc (Cacki) of Baton Rouge, LA; siblings-in-law, Marilyn Walsh (Ed Laskarzewski) of Glastonbury, CT, William “Bill” E. Walsh (Winnie), Marshall T. Walsh (Debbie), and Sara O. Walsh, David L. Walsh, all of Spartanburg, SC, and Natalie W. Bishop of Nashville, TN; along with many nieces and nephews. He was predeceased by a brother-in-law, T. Walsh.

This memorial, which originally ran on the J.F. Floyd mortuary website, was reprinted with permission.

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Journals

Franklin, Buenemann Join Annals of the American Association of Geographers as New Editors

January 6, 2025

Rachel Franklin

Rachel Franklin will take a new position as General Geography/Cross-discipline Editor, and Michaela Buenemann is the incoming Physical Geography, Earth, and Environmental Sciences Editor at Annals of the American Association of Geographers, effective January 2025. Buenemann will replace outgoing editor David R. Butler.

Franklin is a broadly trained human geographer with research expertise in population and spatial analysis. She is professor of Geographical Analysis at Newcastle University, where she researches spatial demography and spatial inequality. She is also keenly interested in pedagogy, especially the teaching of methods. In addition to her new duties at Annals, she edits the journal, Geographical Analysis. She is a visiting academic in Population Studies at Brown University and at the Gran Sasso Science Institute (GSSI) in L’Aquila, Italy. She brings to her work at Annals extensive experience as a member of several journal editorial boards, including Population, Space and Place, the Annals, the Journal of Regional Science, and the Journal of Geographical Systems.

One of Franklin’s primary goals is to “work diligently to promote the Annals and maximize its visibility, both within and outside the discipline.” She is especially interested in highlighting the commonalities across sub-fields, finding common ground throughout the discipline.

Michaela Beunemann Michaela Buenemann, incoming editor for Physical Geography, Earth, and Environmental Sciences, is professor and head of the Department of Geography and Environmental Studies at New Mexico State University. Her interdisciplinary, international, and collaborative work features contributions in GIS, remote sensing, spatial modeling, landscape ecology, and biogeography. She has published in a wide range of geography, environmental sciences, and GIScience journals, and her research has been funded by numerous state and federal agencies. In the classroom and field, she teaches an array of courses in physical geography, socio-environmental systems, field methods, geographic information science and technology, and geographic theory and research design. She has contributed to the discipline of geography in various roles, including chair of the Southwest Division of the American Association of Geographers, Southwest Regional Councilor of the American Association of Geographers, and Southwest Regional Councilor of Gamma Theta Upsilon.

Buenemann brings to her editorship the experiences of seven years on the Editorial Board of the Physical Geography, Earth, and Environmental Sciences thematic area of the Annals. She is currently co-editing an Annals Special Issue on “National Parks and Protected Places” with David Butler and also serves as an Associate Editor for Regional Environmental Change. She earned her Ph.D. in Geography from the University of Oklahoma in 2007.

Photo of David Butler We are grateful to David R. Butler, outgoing editor for Physical Geography, Earth, and Environmental Sciences. Butler is the Regents’ Professor of Geography Emeritus in the Texas State University System and an AAG Fellow. His research interests include geomorphology, biogeography, natural hazards, mountain environments, and environmental change. In 2023, Butler was awarded the AAG Lifetime Achievement Award for his contributions to the discipline.

Find out more about The AAG Annals and other AAG journals.

Journals

Conver Named New Editor of AAG Review of Books

January 6, 2025

Joshua Conver

In January 2025, Joshua L. Conver will become the new editor-in-chief of The AAG Review of Books. Conver is the GIS Librarian in the Center for Digital Scholarship and Curation at Washington State University.

A physical geographer with experience in both academia and public land management, he also has an undergraduate degree in political science and research experience at the Arizona State House of Representatives. With a wide-ranging background that includes the study of humanities and cultural resources, Conver will bring an integrative sensibility to his editorial decisions for The Review.

Conver earned his Ph.D. in Geography from the University of Cincinnati in 2020, and is a longstanding GIS practitioner who earned his certificate in 2013. He has an M.S. in Natural Resources from the University of Arizona and a B.A. in Geography and Political Science, also from the University of Arizona. His research interests include spatial and landscape ecology, cultural and natural resource management, long-term monitoring, public science, integrated GIS, built environments, and data curation.

We express our gratitude to outgoing editor Debbie Hopkins, Associate Professor in Human Geography at the University of Oxford, who has steered the publication since June 2020. Along with editorial assistant Neha Arora, Hopkins worked to bring in book reviews that represent the diversity of the discipline and offer fresh perspectives, highlighting what she calls “that real-worldness of our work.”

Find out more about The AAG Review of Books and other AAG journals.

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