What can SAR Interferometry be used for?
What can SAR Interferometry be used for?
Terrestrial or ground-based SAR interferometry (GBInSAR or TInSAR) is a remote sensing technique for the displacement monitoring of slopes, rock scarps, volcanoes, landslides, buildings, infrastructures etc.
What is interferometry in remote sensing?
The SAR interferometry technique uses two SAR images of the same area acquired at different times and “interferes” (differences) them, resulting in maps called interferograms that show ground-surface displacement (range change) between the two time periods.
What is InSAR technology?
InSAR (Interferometric Synthetic Aperture Radar) is a technique for mapping ground deformation using radar images of the Earth’s surface that are collected from orbiting satellites. Unlike visible or infrared light, radar waves penetrate most weather clouds and are equally effective in darkness.
What is radar baseline?
The distance between the two antenna positions (the so-called baseline) is a multiplier for the phase difference. The baseline should not be too large so that the reflection conditions between the two measurements do not change.
What is differential interferometry?
Differential interferometry (also called shearing interferometry) is a method to measure derivatives of light phase distortions. In practice, this can be done in two ways.
What is SAR coherence?
In SAR interferometry, coherence is used to describe systems that preserve the phase of the received signal. Coherence value can be estimated by means of the “local coherence” of an interferometric SAR image pair.
How is InSAR data collected?
What is the difference between SAR and interferometry?
Unlike SAR, which makes use of both a wave’s amplitude (signal strength) and the phase of the returned signal, interferometry is only concerned with the difference in phase from multiple passes or positions. Phase is affected by interaction with the ground surface (both static and movement), the satellite’s position in orbit and topography.
What is synthetic aperture radar interferometry?
Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface.
What happens when you combine two SAR images?
If the combined SAR images originate from slightly different positions, the topography of the surface can be mapped. In contrast, if images from the same position but taken at different times are combined, the difference between them will show motion, or deformation, of the surface in the time between the two images.
How often are interferometric observations made on the Nisar mission?
For the NISAR mission, interferometric observations of any given point on the ground are acquired every 12 days. To the extent that the ground does not change appreciably in most places over 12 days, surface motion can be measured.
