The most advanced algorithm for ground displacement detection.
In 2010, the new SqueeSAR™ algorithm was unveiled - a second generation PSInSAR™ algorithm.
SqueeSAR™ is the latest technology for the detection of millimetric ground displacements using satellite data. By procesing satellite radar images already acquired over an area of interest, or continiously acquiring, SqueeSAR™ providees retrospective ground displacemt maps for both historical analysis and monitoring projects.
SqueeSAR™ is the only algorithm that TRE offers due the redundancy of the PSInSAR™ algorithm, providing a significantly increased coverage of ground points, especially over non-urban areas. Learn more about SqueeSAR™ deliverables.
As was standard with the previous PSInSAR™ algorithm, SqueeSAR™ continues to identify point-wise permanent scatterers (PS), but advances on the previous algorithm by also exploiting spatially distributed scatterers (DS). Whilst PS usually correspond man-made objects, DS are typically identified from homogeneous ground, scattered outcrops, debris flows, non-cultivated lands and desert areas. Satellite signals are not returned over heavily vegetated areas hence no ground deformation data can be provided. This new approach provides additional data in low-reflectivity homogeneous areas.
Below is a schematic of the distribution of PS and DS over a typical AOI.
SqueeSAR™ exploits both PS and DS, providing a significantly higher density of ground points and hence coverage of ground displacement over the AOI. A summary of the benefits of SqueeSAR™ are given below:
- both Permanant Scatterers (PS) and Distributed Scatters (DS) identified
- high density of ground points supplied
- time-series provided for each ground point identified
- millimetre accuracy on ground displacement values
- time-series standard deviation reduced compared to previous algorithm i.e. coherence increased and noise decreased
- increased confidence on ground behaviour due to increased coverage of points – especially significant for generic areas with low reflectivity
Since its introduction in 2010, as the replacement to the widely accepted PSInSAR™ algorithm, SqueeSAR™ has challenged the industry standard by identifying many more ground points, and hence increasing overall understanding of ground displacement occurring in an AOI.
The image below shows a comparison between the number of ground points identified using the previous PSInSAR™ algorithm and the latest SqueeSAR™ algorithm.
