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Battle-damage detector can help aid groups rapidly respond during war

A simple statistical test can quickly guide humanitarian efforts in areas like Gaza and Ukraine impacted by war – and it could perform as well as more expensive, AI-powered methods
2T5NP48 GAZA CITY, PALESTINE - 10 October 2023 - Widespread damage to buildings near the Palestine Tower in Gaza City after bombardment by Isreali forces, as
Widespread damage to buildings near the Palestine Tower in Gaza City on 10 October 2023 after bombardment by Israeli forces
Geopix/Alamy

An algorithm that detects battle damage can compare satellite images to estimate the number of buildings destroyed and people affected by ongoing conflicts. It has been tested on satellite images of Ukraine and Gaza, and could be used to quickly guide relief and reconstruction efforts by humanitarian organisations.

The algorithm detected differences between intact and damaged buildings in 12 different cities by analysing radar signals from the European Space Agency’s Sentinel-1 satellites. These satellites typically capture a consistent return image when their radar bounces a signal off stationary objects such as buildings.

Gaza damage
Damage as of last month in Gaza highlighted by Ballinger’s tool
Ollie Ballinger /Mapa GISrael/Terra Metrics

at University College London used a straightforward statistical test to compare the radar return signals for each building – and record battle damage based on any statistically significant changes.

This task can stump artificial intelligence because “the models that are used for battle-damage detection are pretty bad at generalising to new geographies”, says Ballinger.

Ukraine Damage Assessment
Battle impacts as of May in Ukraine identified by the tool
Google/Airbus, CNES, Landsat/Copernicus, Maxar Technologies

Compared with images labelled by humans, the method was between 70 and 88 per cent accurate in detecting damaged buildings from a United Nations dataset of more than 633,000 buildings in 12 cities in Ukraine, Gaza, Syria and Iraq.

This tool could prove as accurate as costly AI models in development that often struggle to maintain accuracy in unfamiliar urban environments, says Ballinger. It is also cheaper because it relies on publicly available ESA satellite data.

“Very often we lack data and only the best-funded organisations can afford the satellite pictures we would require for doing real-time monitoring,” says at the Institute for Economic Analysis in Spain.

Mueller thinks this approach is promising but says he wants to see how well the accuracy holds up “in the wild”. So far, Ballinger has created two dashboards through Google Earth for anyone to track the ongoing destruction in and – and he says that a UN team working on humanitarian efforts in Gaza has expressed interest in using the tool.

Reference

arXiv

Article amended on 31 May 2024

We clarified the accuracy of the statistical method compared with human labelling

Topics: Satellites / War