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Space Situational Awareness & Space Traffic Management
Published in M. Madi, O. Sokolova, Space Debris Peril: Pathways to Opportunities, 2020
A frequently unexploited way to dramatically improve positional accuracy is by applying advanced orbit determination algorithms that incorporate as wide a mix of sensors, sensor types, and viewing geometries as possible. The benefits of this are shown in Fig. 2.15. The figure compares the two-sigma error bubble or ellipsoid around the tracked object’s estimated nominal position obtained using only radar or passive RF observations, only optical telescope observations, or the combined set of observations. This illustrates the substantially reduced error ellipsoid that can be obtained when both radar and optical observations are combined or fused.
Precise Orbit Determination Of Leo Satellites Based On Dual-Frequency Gps
Published in Zhengming Wang, Dongyun Yi, Xiaojun Duan, Jing Yao, Defeng Gu, Measurement Data Modeling and Parameter Estimation, 2016
Zhengming Wang, Dongyun Yi, Xiaojun Duan, Jing Yao, Defeng Gu
Kinematic methods of orbit determination are particularly sensitive to erroneous measurements, unfavorable viewing geometry, and data outages, which sometimes restrict their value in practice. Dynamic methods of orbit determination, in contrast, constrain the position estimates of satellites using models of orbit mechanics. This smoothens measurement data at various time points and improves the precision of orbit determination. Moreover, orbit integrals can cross accidental gaps in tracking data and predict orbits through extrapolation.
Improved orbit prediction of LEO objects with calibrated atmospheric mass density model
Published in Journal of Spatial Science, 2019
Junyu Chen, Jianli Du, Jizhang Sang
The great majority of satellites are launched into the LEO region with altitudes of 300–1500 km (Montenbruck and Gill 2012). The accuracy of satellite orbit determination can be a few centimetres when high-precision GNSS (Global Navigation Satellite System) and SLR (Satellite Laser Ranging) data are available, and such high accuracy is essential for many geodetic and geophysical applications, such as Earth gravitational model determination and reference frame determination (Reigber et al. 2004, Tapley et al. 2004, Montenbruck and Ramos-Bosch 2008).