GPS phase accelerations for moving-base vector gravimetry
GPS phase accelerations for moving-base vector gravimetry
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DOI：
10.1007/s001900050130
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发表时间：
1997-09
影响因子：
4.4
通讯作者：
C. Jekeli;R. Garcia
中科院分区：
文献类型：
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作者：
C. Jekeli;R. Garcia
对于使用INS和GPS的航空重力测量，来自两个系统的加速度被差分以产生重力加速度。通常，GPS加速度通过首先求解车辆相对于基站的位置并且随后对垂直分量进行两次时间导数来确定。另一种方法是直接对观测到的相位进行时间微分，从而避免了定位必须解决的周期模糊问题，并且在周跳的情况下充满了（当然不是不可克服的）困难。由于接收器时钟误差在很大程度上不可预测，并施加选择性可用性降级，双差分（在空间）相位加速度被用来获得相对车辆加速度。固定接收机的测试结果表明，加速度矢量可以确定从相位加速度到40秒的平均值为1 mgal的精度。加速度测定的数学公式还突出了某些其他优于传统方法的优点，例如避免了Eötvös校正，尽管必须确定类似的速度效应。
For airborne gravimetry using INS and GPS, the accelerations from both systems are differenced to yield the gravity acceleration. Usually, the GPS acceleration is determined by first solving for the position of the vehicle relative to a base station and subsequently taking two time derivatives of the vertical component. An alternative method is to time-differentiate the observed phases directly, thus avoiding the cycle ambiguity problem that must be solved for positioning and that is fraught with (certainly not insurmountable) difficulties in the event of a cycle slip. Due to the largely unpredictable receiver-clock errors and the imposition of the Selective Availability degradation, doubly differenced (in space) phase accelerations are used to obtain the relative vehicle accelerations. Test results for stationary receivers show that the acceleration vector can be determined from phase accelerations to an accuracy of 1 mgal for 40-s averages. The mathematical formulation of the acceleration determination also highlights certain other advantages over traditional methods, such as the avoidance of the Eötvös correction, although a similar kind of velocity effect must be determined.