Title :
Study of Delay Drift in GNSS-R Altimetry
Author :
Martin-Neira, Manuel ; DaAddio, Salvatore ; Vitulli, Raffaele
Author_Institution :
Electr. Dept., Eur. Space Agency, Noordwijk, Netherlands
Abstract :
Differently to the case of a conventional spaceborne nadir-looking mono-static radar altimeter, where the fly-around time of the pulses remains basically constant (assuming an almost circular orbit around an almost spherical Earth), the bistatic geometry of GNSS-R with the transmitter and the receiver embarked on different satellites imprints a significant temporal variation to the delays of the direct and reflected signals. Within a GNSS-R-based spaceborne ocean altimeter using the PARIS concept, such temporal variation in the delay has to be compensated for with the objective to finely adjust the delay of the direct signal to permanently match with that of the reflected signal according to some a priori model of the geometry. The impact of the residual delay drift on the accuracy and the precision of the range observations is assessed here.
Keywords :
oceanographic techniques; remote sensing by radar; satellite navigation; GNSS-R bistatic geometry; GNSS-R-based spaceborne ocean altimeter; PARIS concept; conventional spaceborne nadir-looking monostatic radar altimeter; delay drift study; direct signal delay; ocean altimetry; pulse fly-around time; reflected signal; Accuracy; Altimetry; Correlation; Delays; Oceans; Receivers; Satellites; GNSS reflectometry; PARIS concept; ocean altimetry;
Journal_Title :
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of
DOI :
10.1109/JSTARS.2014.2307168