Applications of GNSS

GNSS-R, the use of Global Navigation Satellite Systems  (GNSS) reflected signals is a powerful and potentially disruptive technology for remote sensing: wide coverage, pas-
sive, precise, long-term, all-weather and multi-purpose.  GNSS emit very precise signals which will be available for decades as part of an emerging infrastructure resulting from

The use of GNSS signals as a source of opportunity for remote sensing applications, GNSS-R, has been a research area of interest for more than a decade. One of the possible applications of this technique is soil moisture monitoring. The retrieval of soil moisture with GNSS-R systems is based on the variability of the ground dielectric properties associated to soil moisture. Higher concentrations of water in the soil yield a higher dielectric constant and reflectivity, which incurs in signals that reflect from the Earth surface with higher peak power.

Abstract. We combine GPS/MET data from 29 occul-
tations and IGS ground data collected from 160 stations
around the world to perform stochastic tomography of
the ionosphere with a 4×20×20 global grid of voxels ex-
tending from 200 to 650 km above the mean surface of
the Earth. A correlation functional approach that lim-
its the spatial high frequency content of the images is
used, and a Kalman filter is applied in the time direc-
tion. The combination of ground and occultation data