Atmospheric limitations to repeat‐track radar interferometry

In its recent radar imaging mission, the Shuttle Imaging Radar satellite (SIR‐C) devoted three days to repeat‐track interferometry. We have analyzed the data from a test site in the Mojave desert of California. Although good topography (±10 m on 21 m postings) was obtained, most of the error was caused by turbulent water vapor in the lower atmosphere. Spatial structure of 6 km and all smaller sizes was observed. The RMS, one‐way time delay was found to be 0.24 cm. Essentially identical results were obtained at two wavelengths, 24 and 5.7 cm.