Simulation of Multi-satellite GNSS Reflected Signals and Design of Simulator

Using GNSS-R technology for remote sensing of surface parameters has become a new trend in the field of remote sensing. With the rapid development of GNSS-R technology, GNSS-R simulation has become one of the new hot spots. Now the researches of the GNSS-R simulation are all the simulations that consider a single star or a single frequency point, and in actual applications, the signal captured by the receiver is often the reflected signals of multiple stars. In view of this situation, from the perspective of multi-satellite simulation, this paper gives the model of GNSS-R multi-satellite ocean simulation on the basis of analyzing the remote sensing principle, reflection signal model and simulation principle of GNSS-R technology. Based on the GNSS-R multi-satellite ocean simulation model and the fast parallel computing capability of GPU, the GNSS-R multi-satellite ocean simulator was designed. Finally, the direct and reflected signals generated by the GNSS-R multi-satellite simulator were tested and verified. The results show that the positioning result of the direct signal meets the positioning accuracy requirements; The delay-related power results obtained from the simulated two-satellite reflected signals processing are in good agreement with the theoretical model, and the correlation coefficients are all above 0.99; The generated signals are used for GNSS-R height measurement technology, the height measurement error is about 1.4~1.8 m, which is in line with the accuracy of the C/A code ranging receiver; And the parallel operation of the GPU for multi-satellite simulation calculation is 800—900 times higher than the traditional CPU calculation. It proves that the proposed model and the designed simulator are feasible and accurate.