All-weather
Radar satellites observe in the microwave part of the spectrum, which passes through cloud, smoke and haze. A rainy season or a persistent cloud bank does not leave a gap in the record the way it does for optical imagery.
HomeWhat satellite radar can see,
Capabilities
What satellite radar can see,
and how it becomes evidence.
Synthetic aperture radar measures the echo of its own microwave pulses. That makes it independent of weather and daylight, sensitive to tiny changes in distance, and able to cover wide areas from a single pass.
Capabilities
Why radar sees what cameras cannot.
- All-weatherMicrowaves pass through cloud, smoke and haze.
- Day and nightThe satellite brings its own illumination.
- Millimetre-scale motionPhase comparison detects tiny changes in distance.
- Change detectionRepeat passes show where the surface changed.
- Archive since 2014Look back before monitoring began.
- Wide areaOne pass covers a swath up to 250 km wide.
Day and night
A synthetic aperture radar transmits its own pulses and records their echoes, so it does not depend on sunlight. Night-time passes are as useful as daytime ones.
Millimetre-scale motion
Comparing the phase of the returning signal between passes reveals changes in the satellite-to-ground distance far smaller than Sentinel-1's 5.5 cm wavelength. Combined over many passes with good coherence, this gives millimetre-scale sensitivity to relative motion along the radar's line of sight. It is a sensitivity, not a guaranteed accuracy for every site.
Change detection
When the surface changes between passes, through excavation, flooding, collapse or new construction, the radar signal stops matching. Mapping that loss of coherence and the change in brightness shows where something changed, which an analyst then interprets with other evidence.
Archive since 2014
The Copernicus Sentinel-1 archive reaches back to 2014. A new project can therefore start with history: how the ground behaved before an asset was built, before a problem was noticed, or before an event.
Wide area
Sentinel-1's Interferometric Wide mode images a swath of about 250 km, so a site, its surroundings and long corridors are observed together and consistently, without instruments at every point.
How SAR sees
From a radar pulse to a map of moving ground.
- 1
Pulse
The satellite sends microwave pulses towards the ground. They pass through cloud and need no daylight.
- 2
Echo
The surface scatters part of each pulse back. The strength and timing of the echoes form a radar image.
- 3
Interferogram
Comparing the phase of two passes over the same ground turns tiny changes in distance into colour fringes.
Deformation
Many comparisons through time become a map and a history of relative motion, each with its quality context.
How GeoIntel SAR turns radar into evidenceWhat change looks like
Two radar passes over the same ground.
Drag across the image to compare them. This is an illustration, not a measured result.
- 6–12 days
- between repeat passes on a track, depending on the satellites in orbit
- 250 km
- swath width of a single pass in Interferometric Wide mode
- 2.8 cm
- of line-of-sight change per colour fringe; smaller changes show within a fringe
Figures describe the Copernicus Sentinel-1 mission. They are not an accuracy guarantee for any site: what a result can show depends on the surface, the number of passes and their quality, which every GeoIntel SAR result reports alongside its map.
How the radar becomes evidence
Sophisticated radar processing, explained simply.
A raw satellite image is not a ground-motion answer. GeoIntel SAR turns many carefully aligned observations into a time-based view that teams can inspect, understand and act on.
01
Observe the same ground
Radar satellites illuminate the surface and record the returning signal on each pass, day or night and through cloud.
02
Align and compare scenes
Repeat scenes are precisely aligned. Changes in radar phase reveal small differences in satellite-to-ground distance.
03
Build a time series
Many reliable comparisons are combined so persistent patterns become clearer while weak coverage remains visible.
04
Translate the evidence
Relative line-of-sight motion is presented with trends, quality context and an analyst-reviewed explanation.
The sophistication sits behind the map.
Useful evidence comes from combining repeat acquisitions, precise orbit and terrain references, phase comparisons, time-series analysis and quality checks. The result stays qualified as relative radar line-of-sight motion.
Advantages alongside other techniques
Wide-area radar makes ground investigation more targeted, not obsolete.
Each method contributes something different. Radar is strongest when teams need broad, repeatable coverage and historical context.
Surveying & levelling
Best at
Excellent local precision at surveyed points.
Radar adds
Adds the wider movement pattern and repeat context between field campaigns.
GNSS & installed sensors
Best at
Continuous, direct measurements at instrumented locations.
Radar adds
Adds dense spatial context without placing equipment at every point in the area.
Drone & visual inspection
Best at
Detailed views of current surface and asset condition.
Radar adds
Adds repeat regional observation through cloud and darkness, including change that may not be visually obvious.
Satellite radar supports screening, monitoring and prioritisation. GNSS, levelling, field inspection and geotechnical judgement remain essential for local validation, cause and safety decisions.
Data and standards
Where the data comes from, and how it is delivered.
Only the sources, processing and formats in use today are named.
Data and processing
- Copernicus Sentinel-1 C-band radar
- Copernicus Sentinel-2 optical context
- ASF HyP3 interferometric processing
- MintPy open-source time series
Open standards
- Cloud Optimized GeoTIFF
- STAC
- OGC Tile Matrix Set
How results stay trustworthy
- Each organisation's data isolated by row-level security
- Every report approved by an analyst
- Quality and coverage context with every result
- Wording limited to what the evidence shows
Why surface subsidence matters
Explore Ground Motion Ground can change slowly long before the consequences are obvious.
Uneven settlement can affect foundations, roads, rail, pipelines, drainage, mines and industrial sites. Repeat satellite monitoring helps teams screen broad areas and direct field checks to persistent patterns.