An improved model and simulator design of GNSS ocean reflected signals

Global Navigation Satellite System-Reflection (GNSS-R) technology has attracted more and more attention in remote sensing and navigation field, especially in the ocean remote sensing. A feasible GNSS-R model based on reverse thinking method was proposed in our previous work. In this paper, in order to make the model applicable to the case of higher wind speed, we presented an improved GNSS-R model by expanding the range of time delay from 5 to 9 chips. A mathematical derivation was built to guide the design of the model. The number of reflected signals was 30 and the delay interval was 0.3 chip in the newly built model by optimizing the accuracy and computation of the model. Moreover, a GNSS-R software simulator was designed based on the improved GNSS-R model. The simulation reflected signals were compared with the experimental data collected in Yantai, Shandong province. Good agreement was found in the simulation results and experimental data, and the correlation coefficient between two correlation power curves was 0.9964, with the error in retrieving wind speed of 0.8 m/s. These results proved that the improved GNSS-R model and the simulator design can be applied in simulation of GNSS ocean reflected signals.