Multi-Satellite Relative Navigation Scheme for Microsatellites Using Inter-Satellite Radio Frequency Measurements

Abstract

The inter-satellite relative navigation method—based on radio frequency (RF) range and angle measurements—offers good autonomy and high precision, and has been successfully applied to two-satellite formation missions. However, two main challenges occur when this method is applied to multi-microsatellite formations: (i) the implementation difficulty of the inter-satellite RF angle measurement increases significantly as the number of satellites increases; and (ii) there is no high-precision, scalable RF measurement scheme or corresponding multi-satellite relative navigation algorithm that supports multi-satellite formations. Thus, a novel multi-satellite relative navigation scheme based on inter-satellite RF range and angle measurements is proposed. The measurement layer requires only a small number of chief satellites, and a novel distributed multi-satellite range measurement scheme is adopted to meet the scalability requirement. An inter-satellite relative navigation algorithm for multi-satellite formations is also proposed. This algorithm achieves high-precision relative navigation by fusing the algorithm and measurement layers. Simulation results show that the proposed scheme requires only three chief satellites to perform inter-satellite angle measurements. Moreover, with the typical inter-satellite measurement accuracy and an inter-satellite distance of around 1 km, the proposed scheme achieves a multi-satellite relative navigation accuracy of ~30 cm, which is about the same as the relative navigation accuracy of two-satellite formations. Furthermore, decreasing the number of chief satellites only slightly degrades accuracy, thereby significantly reducing the implementation difficulty of multi-satellite RF angle measurements.

Fully Autonomous Orbit Determination and Synchronization for Satellite Navigation and Communication Systems in Halo Orbits

“…Referring to the literature, in [21], the range measurement error between GPS satellites is assumed to be 1 m by using ranging measurementswith a maximum ranging distance of 50,000 km; Ref. [22] proposes a method for relative navigation for microsatellites using inter-satellite measurements, and the range error is assumed to be at a maximum of 10 cm for a maximum ranging distance of 10 km. Another example can be found in [23], where a precise ranging and time synchronization system was implemented based on dual one-way ranging with a precision of the ranging measures of 1.038 m. Ref.…”

Precision Joint RF Measurement of Inter-Satellite Range and Time Difference and Scalable Clock Synchronization for Multi-Microsatellite Formations

“…Considering the advantages and disadvantages of the NTP and the consensus clock synchronization schemes, as well as the distributed multi-satellite measurement scheme in [10], we propose an innovative clock synchronization scheme which is shown in Figure 9. The synchronization process can be described as follows: each satellite only transmits a signal in its own time slot and receives other satellites' signals in the other time slots.…”

“…In [10] It was demonstrated that the measurement accuracy hardly deteriorated as the number of nodes increased, even when the number of nodes reached tens. A three-node experimental platform was established, as shown in Figure 17, to verify the performance and scalability of the proposed joint RF measurement method and clock synchronization scheme for multi-microsatellite formations.…”

“…Although the existing RF measurement research has gained some achievements, two prominent problems still remain. One is that the high-precision inter-satellite RF ranging and time difference measurement have only been investigated separately in existing studies [10,11]. This means that a satellite needs to be equipped with two separate devices, one for inter-satellite ranging and the other for inter-satellite time difference measurement (for example, the GRAIL formation), resulting in an excessively complex space-borne navigation system.…”