摘要：The capabilities of radar altimetry to measure inlandwater bodies are well established, and several river altimetry datasets areavailable. Here we produced a globally distributed dataset, the Global RiverRadar Altimeter Time Series (GRRATS), using Envisat and Ocean SurfaceTopography Mission (OSTM)/Jason-2 radar altimeter data spanning the timeperiod 2002–2016. We developed a method that runs unsupervised, withoutrequiring parameterization at the measurement location, dubbed virtualstation (VS) level, and applied it to all altimeter crossings of ocean-draining rivers with widths >900 m ( >34 % ofthe global drainage area). We evaluated every VS, either quantitatively for VSlocations where in situ gages are available or qualitatively using a gradesystem. We processed nearly 1.5 million altimeter measurements from 1478VSs. After quality control, the final product contained 810 403 measurementsdistributed over 932 VSs located on 39 rivers. Available in situ data allowedquantitative evaluation of 389 VSs on 12 rivers. The median standard deviation ofriver elevation error is 0.93 m, Nash–Sutcliffe efficiency is 0.75, andcorrelation coefficient is 0.9. GRRATS is a consistent, well-documenteddataset with a user-friendly data visualization portal, freely available foruse by the global scientific community. Data are available at https://doi.org/10.5067/PSGRA-SA2V1 (Coss et al., 2016).
