4.9 Autonomous Navigation Technology for Spacecrafts
265
nuclear explosion monitoring through the GPS satellites is shown in Fig. 4.13, from
which it can be seen that the inter-satellite link is the core technology of the nuclear
explosion monitoring, and the abnormal event information is quickly transmitted to
the ground information collection center through the inter-satellite link.
In the mean time, the researchers also discussed how to improve the orbit determination accuracy of navigation satellites by using the information from the twoway ranging and communication crosslink between the satellites, and theoretically
demonstrated the feasibility of autonomous navigation for the GPS constellation.
In 1984, M. P. Ananda, et al. from the IMB gave the theoretical demonstration
results of GPS satellites’ autonomous navigation for the first time [19]. Moreover,
the JPO entrusted Rockwell Automation Inc. to study the engineering feasibility
for the GPS Block II satellites to realize autonomous navigation. It was shown for
the studied results that the GPS satellites could achieve the autonomous navigation as long as the onboard data processing units were properly modified and the
corresponding payloads similar to the nuclear explosion monitoring process were
equipped with. The basic principle of the GPS satellites’ autonomous navigation is
Fig. 4.13 Flowchart of nuclear explosion monitoring of GPS
265
nuclear explosion monitoring through the GPS satellites is shown in Fig. 4.13, from
which it can be seen that the inter-satellite link is the core technology of the nuclear
explosion monitoring, and the abnormal event information is quickly transmitted to
the ground information collection center through the inter-satellite link.
In the mean time, the researchers also discussed how to improve the orbit determination accuracy of navigation satellites by using the information from the twoway ranging and communication crosslink between the satellites, and theoretically
demonstrated the feasibility of autonomous navigation for the GPS constellation.
In 1984, M. P. Ananda, et al. from the IMB gave the theoretical demonstration
results of GPS satellites’ autonomous navigation for the first time [19]. Moreover,
the JPO entrusted Rockwell Automation Inc. to study the engineering feasibility
for the GPS Block II satellites to realize autonomous navigation. It was shown for
the studied results that the GPS satellites could achieve the autonomous navigation as long as the onboard data processing units were properly modified and the
corresponding payloads similar to the nuclear explosion monitoring process were
equipped with. The basic principle of the GPS satellites’ autonomous navigation is
Fig. 4.13 Flowchart of nuclear explosion monitoring of GPS