SARLab
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Geographisches Institut » Fernerkundung/Remote Sensing Laboratories » Prof. Dr. Michael Schaepman » SARLab
Completed research project
| Title / Titel | SAR Interferometry | ||||||
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| Abstract (PDF, 14 KB) | |||||||
| Summary / Zusammenfassung | The amplitude information within SAR images was first processed digitally in the 1970's, but more recently, one has begun using the phase information also inherent in each data set. The phase information of a *single* data set is typically uniformly distributed, but it can be correlated to the phases of a *second* data set acquired with a similar geometry. The second acquisition can be acquired either simultaneously (single-pass: usually airborne sensors) or after a time-interval, possibly by the same sensor (multiple pass: often spaceborne). The phase differences between two acquisitions contain information describing the topography of the scene. The sensitivity of the phase information to height depends on the relative geometry (baseline) of the two flight tracks. Since phase information is known only modulo two pi, an *unwrapping* process is required before height extraction is possible. In the multiple-pass case, changes between acquisitions can decorrelate the phase signal (e.g. water bodies, forest) - no local height information is then available. Differential InSAR uses either a *third* data acquisition or an existing reference DEM to compensate for the effects of known topography on the phase. Residual phase trends are due to changes in topography between acquisitions. Changes in the atmospheric path length between acquisitions can also cause local disturbances in the phase. The phase signature of an earthquake was detected using ERS-1 SAR data acquired over Konitsa, Greece. |
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| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Universität Zürich (position pursuing an academic career), Others ESA, DLR |
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| In collaboration with / In Zusammenarbeit mit |
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| Duration of Project / Projektdauer | Jan 1994 to Jan 2006 |