On the influence of the ground track on the gravity field recovery from high–low satellite-to-satellite tracking missions: CHAMP monthly gravity field recovery using the energy balance approach revisited
On the influence of the ground track on the gravity field recovery from high–low satellite-to-satellite tracking missions: CHAMP monthly gravity field recovery using the energy balance approach revisited
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DOI：
10.1007/s00190-009-0330-5
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发表时间：
2009-07
影响因子：
4.4
通讯作者：
M. Weigelt;M. Sideris;N. Sneeuw
中科院分区：
文献类型：
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作者：
M. Weigelt;M. Sideris;N. Sneeuw
本文针对高-低卫星跟踪任务的情况，研究了地面轨道覆盖对月重力场解质量的影响。2002年4月至2004年2月期间收集的具有挑战性的小卫星有效载荷(CHAMP)飞行任务的数据已用于将重力场恢复到每月70度。质量主要受仪器精度的制约。此外，在研究期间，通过31/2重复模式三次切分，导致空间采样不足和解的退化。与科伦坡的经验法则(两颗卫星的全球重力测绘，大地测量学出版物，第7卷(3)，荷兰大地测量委员会，1984年)相反，另见Wagner(J GeoD 80(2)：94-103,2006)，我们发现每月的解决方案本身可以恢复到大约30度，而不是15度。为了改进每月的重力解决方案，制定了两种战略：限制在较低的程度，以及通过引入同期卫星飞行任务的额外敏感测量来增加采样密度。后一种方法是通过将重力测量和重力恢复与气候实验(GRACE)的数据结合起来进行测试的。注意，两个人造卫星在这里被认为是独立的，即不使用K波段测距数据。这样，我们能够几乎完全消除地面轨道的影响，将仪器的精度作为月度解决方案质量的主要限制。这些发现对即将到来的蜂群任务特别有趣，因为它将由类似于组合香槟(优雅)任务的配置组成。
In this paper, the influence of the ground track coverage on the quality of a monthly gravity field solution is investigated for the scenario of a high–low satellite- to-satellite tracking mission. Data from the CHAllenging Minisatellite Payload (champ) mission collected in the period April 2002 to February 2004 has been used to recover the gravity field to degree and order 70 on a monthly basis. The quality is primarily restricted by the accuracy of the instruments. Besides,champpassed through a 31/2 repeat mode three times during the period of interest resulting in an insufficient spatial sampling and a degraded solution. Contrary to the rule of thumb by Colombo (The global mapping of gravity with two satellites, Publications on Geodesy, vol 7(3), Netherlands Geodetic Commission, The Netherlands, 263 pp, 1984), see also Wagner (J Geod 80(2): 94–103, 2006), we found that the monthly solutions themselves could be recovered to about degree 30, not 15. In order to improve the monthly gravity solutions, two strategies have been developed: the restriction to a low degree, and the densification of the sampling by the introduction of additional sensitive measurements from contemporaneous satellite missions. The latter method is tested by combining thechampmeasurements with data from the Gravity Recovery And Climate Experiment (grace). Note that the twogracesatellites are considered independent here, i.e. no use is made of the K-band ranging data. This way, we are able to almost entirely remove the influence of the ground track leaving the accuracy of the instruments as the primary restriction on the quality of a monthly solution. These findings are especially interesting for the upcomingswarm-mission since it will consist of a similar configuration as the combinedchampand (grace) missions.