A High Precision Real-Time Low Order Polynomial Interpolation Method for GNSS Satellite Orbit

As an important testing method for integrated navigation receiver and hardware-in-loop simulation, real-time closed-loop navigation signal simulator needs to make the input external trace presented on output signal in ms. While constellation orbital calculation plays an important role in signal parameters generation, its computing efficiency has an important influence on time performance of simulator. The calculation load distribution of simulator constellation orbit interpolation based on sliding newton interpolation method is analyzed, and it's pointed out that the interpolating polynomial calculation efficiency is an important factor affecting the calculation load. A real-time precision satellite orbit low order polynomial interpolation method is proposed, which reduces the calculation load significantly without decreasing precision. The results also show that the new method speed up calculation six times than the direct 7-order sliding newton interpolation method for position error less than millimeter and velocity error less than 10(-5) m/s, and obviously promoting the real-time performance.