GNSS Remote Sensing of the Arctic and Ocean using Spaceborne Reflectometry

CYGNSS NBRCS (?0) over two mid-latitude mesoscale ocean eddies near the south coast of Japan at two different times; in 3 dimensions in the local defined coordinate system. The evolution of the ?0 can be explained by the anomalies of sea surface temperature. The warm core of the top eddy produces higher wind speed (lower ?0) while the colder edges, by contrast, cause lower wind speeds (higher ?0). © M. Hoseini

Mostafa Hoseini

Norwegian University of Science and Technology NTNU, Trondheim, Norway
GFZ Potsdam
Fakultät VI - Planen Bauen Umwelt, Technischen Universität Berlin

Remote sensing using signals of Global Navigation Satellite Systems (GNSS) is a method providing a new source of observations to study the Earth System including its atmosphere. GNSS Reflectometry (GNSS-R) is element of GNSS Remote Sensing and a novel observation technique. It exploits reflected GNSS signals from land, ice or water bodies to retrieve information about different geophysical parameters. This technique has been increasingly used in ground-based, air- or spaceborne configuration. It is being pursued for a variety of applications over land, ocean and ice. Different processing approaches could be developed and applied to get geophysical information with unprecedented high accuracy and spatiotemporal resolution.

Several GNSS-R sensors onboard small satellite missions have already demonstrated the feasibility and huge potential of this technique for Earth Observation on global scale. Although NASA CYGNSS (CYclone GNSS) mission currently provides GNSS-R data over tropical regions, the coverage at higher latitudes regions including Polar areas has to be improved.

The joint project of the Norwegian University of Science and Technology (NTNU), GFZ and TUB will focus on investigation of the theory and design of an Earth remote sensing sensor onboard small satellites capable of measuring the oceanographic parameters related to altimetry in Norwegian and Polar waters. The project exploits the GNSS-R concept, which allows to use a cost-efficient low-power passive sensor in a compact payload onboard future NTNU SmallSats.

The project provides required information about the methodology and instrumentation of an observing system with different geophysical parameters of interest such as sea ice thickness, sea surface height and wave height. The results will be used to design the NTNU SmallSats, which will be integrated into an operational maritime/Arctic observation network. It is foreseen to use in-situ measurements acquired by autonomous unmanned vehicle systems for calibration and enhancement of the GNSS-R products. The ultimate goal is to integrate the designed GNSS-R sensor into a complex observation network to provide a high spatiotemporal resolution monitoring of the arctic and oceans, as key components of the Earth’s climate system.