Glossary.
Terms used across PILLAR, in plain language.
InSAR
Interferometric synthetic aperture radar. Measures millimetre-scale movement from phase differences between radar images taken on different dates.
SAR
Synthetic aperture radar. A satellite sensor that sends its own signal and images the ground at night and through cloud.
Sentinel-1
The Copernicus radar mission. Its data is free and is PILLAR’s default source.
ARIA GUNW
Geocoded unwrapped interferograms from Sentinel-1, published by NASA’s ARIA project.
HyP3
The on-demand SAR processing service of the Alaska Satellite Facility, used when public pairs are scarce.
NISAR
A radar mission built by NASA and the Indian Space Research Organisation.
ERA5
The ECMWF climate reanalysis: temperature, humidity, rain and more.
TimesFM
A time-series forecasting model. PILLAR forecasts displacement six months ahead with a 10–90% band.
Angular distortion
Differential settlement divided by the distance between two points. 1/1000 means 1 mm per metre.
Carbonation
Carbon dioxide lowering the alkalinity of concrete, which can lead to rebar corrosion.
Chloride ingress
Chloride from seawater or de-icing salt moving into concrete, modelled with Fick’s second law.
Cover
The concrete thickness between the rebar and the surface.
Freeze–thaw
Repeated freezing and thawing of water that damages concrete surfaces.
Monte Carlo
Drawing inputs at random many times to get a distribution of results. PILLAR uses 600 draws.
p10 / p50 / p90
The 10%, 50% (median) and 90% points of a result distribution.
SHI
Structural Health Index, PILLAR’s 0–100 screening index.
PSR
Periodic safety review, a nuclear regulatory process that PILLAR does not replace.
ISO 9223/9224
International standards for atmospheric corrosivity classes and metal loss estimates.
Related pages
Work with us
Start with a screening pilot.
No equipment on site. We screen your structures from public satellite and climate data first, then compare the priority list with your own inspection and survey results.