Here we present a comparison of Sentinel-1 and NISAR InSAR observations at 6 and 24 cm wavelengths, as applied to many Earth science studies. Specifically we present some of the first sequences of interferograms and derived products comparing these sensors and their observed InSAR statistics, including phase artifacts, correlation quality, frequency of phase unwrapping errors, and sensitivity to objects at depth both under the surface and in heavily vegetated regions. In this work we process both sensors’ data using the same backprojection and data flow codes so as to minimize changes arising from disparate processing systems, hence the observed differences may be attributed to sensor-related artifacts and true differences in radar scattering at the two wavelengths. We expect the NISAR 24-cm wavelength will lead to more complete coverage in decorrelating terrains from both higher correlation and decreased fringe rates, albeit at the expense of much more sensitivity to ionospheric distortions and artifacts. We note that Sentinel-1 has the advantage of both an eight year observation history and a planned 30 year lifetime, admitting many longer term studies. These data will point the way to more comprehensive analyses as more data are accumulated.