Some research centres and other companies were inspired to develop their own algorithms which would also overcome InSAR's limitations. In scientific literature, these techniques are collectively referred to as Persistent Scatterer Interferometry or PSI techniques. The term Persistent Scatterer Interferometry (PSI) was created by ESA to define the second generation of radar interferometry techniques.
Commonly such techniques are most useful in urban areas with lots of permanent structures, for example the PSI studies of European cities undertaken by the Terrafirma project.[13] The Terrafirma project (led by Fugro NPA) provides a ground motion hazard information service, distributed throughout Europe via national geological surveys and institutions. The objective of this service is to help save lives, improve safety, and reduce economic loss through the use of state-of-the-art PSI information. Over the last 5 years this service has supplied information relating to urban subsidence and uplift, slope stability and landslides, seismic and volcanic deformation, coastlines and flood plains.
引用
^Massonnet, D.; Feigl, K. L., Radar interferometry and its application to changes in the earth’s surface, Rev. Geophys. 36 (4), 1998, 36 (4): 441–500, doi:10.1029/97RG03139
^Burgmann, R.; Rosen, P.A.; Fielding, E.J., Synthetic aperture radar interferometry to measure Earth's surface topography and its deformation, Annual Review of Earth and Planetary Sciences 28, 2000, 28: 169–209, doi:10.1146/annurev.earth.28.1.169
^Hanssen, Ramon F., Radar Interferometry: Data Interpretation and Error Analysis, Kluwer Academic, 2001, ISBN 9780792369455
^ 4.04.1Massonnet, D.; Rossi, M.; Carmona, C.; Adragna, F.; Peltzer, G.; Feigl, K.; Rabaute, T., The displacement field of the Landers earthquake mapped by radar interferometry, Nature 364, 1993, 364: 138–142, doi:10.1038/364138a0
^ 5.05.1Massonnet, D.; Briole, P.; Arnaud, A., Deflation of Mount Etna monitored by spaceborne radar interferometry, Nature 375, 1995, 375: 567–570, doi:10.1038/375567a0
^Wadge, G., A strategy for the observation of volcanism on Earth from space, Phil. Trans. Royal Soc.Lond. 361, 2003, 361: 145–156
^Rosen, P. A.; Hensley, S.; Zebker, H. A.; Webb, F. H.; Fielding, E. J., Surface deformation and coherence measurements of Kilauea Volcano, Hawaii, from SIR C radar interferometry, J. Geophys. Res. 101 (E10), 1996, 101 (E10): 23,109–23,126, doi:10.1029/96JE01459
^Stevens, N.F.; Wadge, G., Towards operational repeat-pass SAR interferometry at active volcanoes, Natural Hazards 33, 2004, 33: 47–76, doi:10.1023/B:NHAZ.0000035005.45346.2b
