What Makes Scatterers Good or Poor?

Persistent Scatterer Interferometric Synthetic Aperture Radar (PS InSAR) analysis relies on identifying stable and coherent radar reflections from certain materials on the Earth's surface over time. Whether a material makes a good or a poor scatterer depends on its ability to reflect radar signals consistently.

Persistent Scatterer InSAR is an Accurate Method for Monitoring Earth's Infrastructure

Good Scatterers

Urban Infrastructure

These include buildings, bridges, and any other man-made structures with rigid surfaces. These structures typically have stable and well-defined surfaces that reflect radar signals effectively.

Rocky Surfaces

The coarse, stable nature of exposed rock surfaces or cliffs provide good scattering properties.

Permanent Ice and Glaciers

Ice surfaces such as the polar ice caps are good scatterers, especially when stable and undisturbed.

Ice Features Such as Glaciers Can Be Good Scatterers for InSAR

Certain Vegetation

Persistent and dense canopies like coniferous forests can form suitably solid surfaces for reflection.

Poor Scatterers

Smooth Surfaces

Smooth surfaces such as calm water bodies or certain agricultural fields with smooth surfaces can cause signal cancellation and are not ideal for PS and InSAR.

Vegetated Areas with High Temporal Changes

Vegetation that undergoes significant temporal changes, such as farmland with crops that are regularly ploughed or harvested, can cause decorrelation and affect the quality of InSAR signals.

Loose or Unconsolidated Soils

Unstable or loose surfaces like sand dunes can lead to phase decorrelation, making it challenging to track persistent scatterers.

Sand Dunes are Unconsolidated and are Poor Scatterers

Conclusion

The success of Persistent Scatterer InSAR analysis depends on various factors, including the specific characteristics of the radar system, the wavelength used, and the temporal and spatial resolution of data.