The GNSS receiver for occultation, reflectometry and scatterometry (GORS) has been designed and developed within the framework of the GITEWS project (German Indonesian Tsunami Early Warning System Project, 2006 bis 2009) by the Russian-American manufacturer JAVAD GNSS for the project partners GFZ and DLR. Initially, the instrument was based on the 72-channel GeNeSiS-112 receiver board; in 2008 TR-G3T modules based on the 216-channel Triumph chip set were introduced. Later development utilized the Duo-G2D and Quattro-G3D modules featuring two an four antenna input lines, respectively. These receivers support the GPS L1/L2/L2C as well as the Galileo-E1 signals.
For the GORS project the manufacturer JAVAD GNSS created customized firmware versions which provide position solutions as well as carrier phase and pseudorange data with high temporal resolution. In addition, these firmware version output of I/Q vectors with 200 Hz sampling rate and cloning of two or more detection channels (channel slaving). Control and monitoring of the individual receiver channels during an observation is accomplished with JPS commands sent via the RS232 interface. The high bandwidth of the USB interface allows to handle high-rate measurement data from several channels simultaneously. These JAVAD receivers with modified firmwares were successfully used in a number of ground-based and airborne measurement campaigns.
J. Beckheinrich , G. Beyerle, Steffen Schön, H. Apel, M. Semmling and J. Wickert; GNSS Reflectometry: Innovative flood monitoring of the Mekong Delta, International Journal of Remote Sensing (2013), submitted for review.
Helm A., Stosius R., Beyerle G., Montenbruck O., Rothacher M.; Status of GNSS reflectometry related receiver developments and feasibility studies in the frame of the German Indonesian Tsunami Early Warning System; IAGRSS-07; International Geoscience and Remote Sensing Symposium 2007; 23-27 July 2007, Barcelona (2007).
Helm A., Montenbruck O., Ashjaee J., Yudanov S., Beyerle G., Stosius R., Rothacher M.; GORS - A GNSS Occultation, Reflectometry and Scatterometry Space Receiver; ION-GNSS-2007 Conference; 26-28 Sept. 2007; Fort Worth, Texas (2007).
Helm A., Beyerle G., Stosius R., Montenbruck O., Yudanov S., Rothacher M.; The GNSS Occultation, Reflectormetry and Scatterometry Space Receiver GORS: Current Status and Future Plans within GITEWS; 1st Colloquium Scientific and Fundamental Aspects of the Galileo Programme; 1-4 Oct 2007, Toulouse (2007).
Semmling, A. M.; Beyerle, G.; Stosius, R.; Dick, G.; Wickert, J.; Fabra, F.; Cardellach, E.; Ribó, S.; Rius, A.; Helm, A.; Yudanov, S. B.; d'Addio, S.: Detection of Arctic Ocean tides using interferometric GNSS-R signals. Geophysical Research Letters, 38, L04103 (2011). doi:10.1029/2010GL046005
Semmling, A. M., J. Wickert, S. Schön, R. Stosius, M. Markgraf, T. Gerber, M. Ge, and G. Beyerle, A zeppelin experiment to study airborne altimetry using specular Global Navigation Satellite System reflections, Radio Sci., 48, 427–440 (2013). doi:10.1002/rds.20049
A. M. Semmling, G. Beyerle, J. Beckheinrich, J. Wickert, S. Schön, F. Fabra, H. Pflug, K. He, J. Schwabe, M. Scheinert, Tracking the Sea Surface with GNSS-R phase observations recorded during the GEOHALO flight mission, in preparation