[Satellite Analysis] Notice Regarding Satellite Analysis of the Kumamoto Earthquake

Detection of Damage and Ground Surface Changes at Aeon Mall Kumamoto Using Sentinel-1 Data (Coherence Analysis)

Following the earthquake that struck the Kumamoto region of Kumamoto Prefecture on July 28, 2026, New Space Intelligence (NSI) analyzed changes to the ground surface and buildings around Aeon Mall Kumamoto using data from the European Earth observation satellite "Sentinel-1."

The analysis employed a technique known as "coherence analysis," which compares radar images taken before and after the disaster. This method allows for the wide-area identification of locations where significant changes to the ground surface or buildings may have occurred, utilizing satellite data that is largely unaffected by cloud cover or rain.

Analysis Results

Coherence analysis was conducted using Sentinel-1 data acquired on July 17, 2026 (pre-earthquake), and July 29, 2026 (post-earthquake).

The results revealed areas with significantly lower coherence values ​​within the zone identified as having sustained damage at Aeon Mall Kumamoto, compared to the surrounding urban area (see figure below).

•    Coherence value for the target area: 0.1246

•    Display on analysis image: Purple to dark blue

The coherence value is an indicator of the degree of similarity between ground surface conditions at two different times. A value close to 1 indicates minimal change, while a value close to 0 suggests a high probability of significant change.

The observed drop in values ​​likely captures changes to the ground surface and structures—such as alterations in building shapes, collapses, or the accumulation of debris—resulting from the earthquake and the subsequent explosion.

However, coherence values ​​can also fluctuate due to factors such as vegetation, rainfall, and observation conditions. Therefore, these analysis results alone do not definitively determine the type or extent of the damage; verification through on-site surveys and the use of aerial or drone imagery is necessary.

Analysis Image

1. Wide-area analysis around AEON MALL Kumamoto (vicinity of Kashima Town, Kamimashiki District, Kumamoto Prefecture)

Urban areas and locations with stable structures are generally displayed in yellow to green. Conversely, areas where changes to the ground surface or buildings may have occurred appear with low coherence values.

Contains modified Copernicus Sentinel data 2026

2. Detailed analysis of the area surrounding AEON MALL Kumamoto

In the area indicated by the circle, coherence values ​​are lower than in the surrounding areas, appearing in shades ranging from purple to dark blue.

Contains modified Copernicus Sentinel data 2026

What is Coherence Analysis?

Sentinel-1 is a SAR (Synthetic Aperture Radar) satellite that transmits radio waves to the Earth's surface and observes the reflections. Unlike optical satellites, it can observe the ground surface day or night, even through cloud cover.

Coherence analysis compares two SAR datasets acquired at different times to assess the degree of change in the ground surface conditions.

•  Close to 1.0: Minimal change; conditions are stable.

•  Close to 0.0: Significant changes may have occurred to the ground surface or structures.

By leveraging this characteristic, it is possible to narrow down areas where damage may have occurred across a wide region—even in the immediate aftermath of a major disaster when on-site access is difficult.

Data Used and Analysis Conditions

•  Satellite: Sentinel-1

•  Operator: EU / European Space Agency (ESA) Copernicus Programme

•  Observation Method: C-band SAR

•  Data Used: Sentinel-1 SLC data

•  Analysis Method: InSAR coherence analysis

•  Polarization: VH polarization

•  Pre-earthquake observation date: July 16, 2026, 21:16 (UTC)

•  Post-earthquake observation date: July 28, 2026, 21:16 (UTC) (Data acquired: July 29, 2026, 06:16 JST)

• Target Earthquake: Occurred around 16:27 on July 28, 2026, in the Kumamoto region of Kumamoto Prefecture

•  Magnitude: 7.1

•  Maximum Seismic Intensity: Shindo 7

Future Outlook

Analysis using satellite data enables the rapid, wide-area identification of potential damage sites following a disaster, helping to determine priorities for on-site surveys, rescue operations, and recovery efforts.

NSI remains committed to contributing to disaster prevention, mitigation, and rapid recovery by transforming satellite data into actionable information for use in the field.

Inquiries: New Space Intelligence, Inc.

info@newspaceint.com