RT Journal Article
SR Electronic
T1 Characterization and mitigation of interference between GNSS radio occultation and reflectometry signals for low-altitude occultations
JF NAVIGATION: Journal of the Institute of Navigation
JO NAVIGATION
FD Institute of Navigation
SP 537
OP 546
DO 10.1002/navi.375
VO 67
IS 3
A1 Ian Collett
A1 Y. T. Jade Morton
A1 Yang Wang
A1 Brian Breitsch
YR 2020
UL https://navi.ion.org/content/67/3/537.abstract
AB This research investigates the mutual interference between a GNSS signal refracted through the atmosphere and the same signal reflected from the surface below. For low-altitude occultations, the reflected signal can be present as multi-path when tracking the direct signal. This poses a problem when making remote sensing measurements using GNSS-RO or GNSS-R techniques. Here, this issue is addressed in the context of GNSS data collected by a mountaintop receiver on the Hawaiian island of Maui. First, an elevation-angle threshold, below which the reflected signal can be present as multipath on the direct signal, is calculated for the mountaintop geometry. Next, the first steps are taken to mitigate the mutual interference between the direct and reflected signals. A frequency-domain filtering approach and a time-domain smoothing approach are applied to the signal intensity in an effort to separate the multipath contribution and the direct signal contribution.