  This paper provides an overview of operational applications of GNSS-R, and
describes Oceanpal, an inexpensive, all-weather, passive instrument for remote
sensing of the ocean and other water surfaces. This instrument is based on the
use of reflected signals emitted from GNSS, and it holds great potential for
future applications thanks to the growing, long term GNSS infrastructure. The
instrument exploits the fact that, at any given moment, several GNSS emitters
are simultaneously in view, providing separated multiple scattering points with
different geometries. Reflected signals are affected by surface roughness and
motion (i.e., sea state, orbital motion, and currents), mean surface height and
dielectric properties (i.e., salinity and pollution). Oceanpal is envisioned as
an accurate, "dry" tide gauge and surface roughness monitoring system, and as
an important element of a future distributed ocean remote sensing network
concept. We also report some results from the Starlab Coastpal campaign,
focusing on ground GNSS-R applications.
