An active open-source intelligence community has been created to keep track of troops as soldiers and citizens provide information in semi-real time from the front lines and war-affected areas in Ukraine, which is two years old as of February 24, 2024. activity, destruction and other aspects of war.
Remote sensing complements this approach by providing a safe tool to examine inaccessible or hazardous areas. For example, seismologists documented increased intense bombardment and artillery fire around Kiev in the first few months of the war.
Previously, Teng Wang, a professor at Peking University in China, and I (both Earth scientists) had examined illegal nuclear testing in North Korea with satellite data.
Putting our skills to good use once again, we analyzed the evolution of the war from space together with our graduate student Hang Xu. We used only open source, freely accessible data to ensure that all our findings could be reproduced, guaranteeing transparency and impartiality.
look from above
Sensors on satellites record electromagnetic waves emitted or reflected from the Earth’s surface at wavelengths ranging from hundreds of nanometers to tens of centimeters, enabling semi-continuous monitoring on a global scale, unimpeded by political borders and natural barriers.
The equivalent of photographs taken from space, optical images help governments, researchers and journalists track the movements of front-line troops and the destruction of equipment and facilities. Although optical images can be easily interpreted, they suffer from cloud cover and only work in daylight.
To counter these problems, we used radars on satellites. Radar systems in space beam long-wavelength electromagnetic waves toward Earth and then record the echoes returning. These waves, about 0.4 to 4 inches (1 to 10 centimeters) across, can penetrate clouds and smoke. Radar interferometry has already proven to be an invaluable tool for monitoring widespread damage caused by natural disasters.
radar from space
Free, publicly available radar data for civilian applications is rare—the United States is scheduled to launch its first radar in March 2024—but the European Space Agency has been making such data available since the early 1990s. Data from the European Space Agency’s Sentinel-1 satellite radar can be accessed free of charge through data centers.
Two radar images created over the same area can be used to detect changes in structures and other surfaces. Interferometry measures the travel time difference between two radar signals, which is a measure of the change in the shape or position of surfaces. Another measure of surface variation is the consistency of reflected signals; that is, it is the degree of similarity between two different images when neighboring pixels at the same location in the two images are compared. Great consistency means little change and therefore ensures the preservation of a building or other structure. On the other hand, in the battlefield context, loss of coherence means damage or destruction of a building or structure.
The Sentinel-1 radar’s spatial resolution of 66 feet (20 meters) over a 255-mile (410-kilometer) area and 12-day updates make radar data ideal for monitoring urban warfare. Previous research studies have used satellite radar data to assess damage in Kiev and Mariupol. We used the data to analyze the evolution of damage to cities over time during several long wars.
extent of destruction
Within areas classified as artificial surfaces by the European Space Agency’s WorldCover 2021 dataset, we marked high-damage areas by comparing pre- and post-war radar coherence. With this approach, we first analyzed the Battle of Bakhmut, one of the longest and bloodiest battles of the war, which started on October 8, 2022 and ended with Russia’s victory on May 20, 2023.
When Hang Xu showed Teng Wang and me the data he had processed, we were astonished. We saw a checkerboard pattern all over the city. We quickly realized the gravity of the situation. After a year of war, the only thing left standing was the road network in the city. Due to constant bombardment, all buildings were partially or completely destroyed.
We then took a look at the battles of Rubizhne, Sievierodonetsk and Lysychansk, which started in April 2022 and ended with Russia’s victory on July 2, 2022. The relatively minor destruction of Lysychansk is explained by the rapid siege of the city from the south. Continuation of frontal attacks as in Bakhmut. Radar data shows the extent of destruction, revealing destruction far from the front lines of cities.
Destruction in focus
Remote sensing imagery offers ways to safely monitor the impact of armed conflict, especially as high-intensity warfare in urban environments proliferates. Open-access satellite tools complement other types of open-source intelligence by offering unimpeded access to high-resolution, unbiased information that can help people grasp the true impact of war on the ground.
The picture is clear: The real story of war is destruction.
This article is republished from The Conversation, an independent, nonprofit news organization providing facts and analysis to help you understand our complex world.
Written by: Sylvain Barbot, USC Dornsife College of Letters, Arts and Sciences.
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Sylvain Barbot receives funding from the National Science Foundation.