Atmospheric artifact on mount Etna SIRC interferogram. The first image represents a differential interferogram over mount Etna. The relief has been removed. The second image is the simulated artifact and the third image is the difference between the real and simulated artifacts. 3-Artifacts due to an heterogeneous atmosphere Atmospheric heterogeneities can also produce artifacts.
Ionospheric irregularities can be important.
In the troposphere, the refractive index varies essentially with water content. Under stable conditions, the wator pressure changes slowly horizontally. It has been observed smooth changes of the order of 0.3 fringes on ERS interferograms. Fringe pattern due to growing cumulus on the Landers site. Fringes due to the relief are seen in the top and bottom of the image.