基于精密单点定位的航空重力仪运动加速度估计

本文针对航空重力测量中利用单基准站差分GNSS方法估计载体加速度的局限性，提出了两种基于PPP的载体加速度高精度估计方法—位置差分法和相位差分法。在详细推导了两种估计方法解算方程的基础上，研究总结了方法各自的特点与优势，最后通过实验分析了卫星导航误差源对两种方法的影响。实验研究表明，相位差分法在抑制低阶误差方面更具优势；-2~+2周的整周模糊度解算偏差对位置差分法的加速度估计结果在滤波后产生近10mGal的影响；在数据采样间隔为1s时，1周的周跳对相位差分法的加速度估计结果产生数千mGal的误差。研究结果能为航空重力测量中利用PPP高精度估计重力仪加速度提供一定的理论指导，尤其对难以建站的测区的重力测量具有重大意义。

Airborne Gravitometer Kinematic Acceleration Determination Based on Precise Point Positioning

In order to overcome the limitation of acceleration determination by using differential GNSS method with single reference station in airborne gravity surveying, two methods of high accuracy acceleration determination based on PPP were proposed, namely position difference method and phase difference method. On the basis of deducing the solving equations, the paper researched and summarized the characteristics and advantages of each method, and finally analysed the influence of satellite navigation error sources toward the two methods through experiments. The experiments showed that the phase difference method had more advantages in restraining the low-order errors; in position difference method, integer ambiguity error within -2 to 2 cycles had an impact of nearly 10mGal on the acceleration after filtering; and in phase difference method, when the sample interval was 1s, the acceleration bias produced by 1 cycle slip would reach more than one thousand mGal. The study results provided some theoretical guidance for high accuracy acceleration determination of gravitometer in PPP-based airborne gravity surveying. Especially, the research was of great significance for the gravity surveying in the area where are difficult to establish stations.