5.9 Future of Navigation Satellite System
407
requirements for active navigation and high-baud-rate communication in the
deep-space exploration and interstellar flight missions.
(3) The ground support segment is composed of a small number of the GNSS
ground control stations and the radio observation stations, which are responsible for post-processing the orbit and time determination of the GNSS satellites
to evaluate the GNSS performance; integrating the radio and X-ray pulsar data
to build the fundamental database and provide the post-processing service;
as well as regularly dumping and correcting the accumulated model errors of
orbit determination and time synchronization data processing for the reference
constellation satellites.
(4) The navigation application segment consists of the GNSS user terminals on
the ground and in the near-earth space, and the X-ray detector terminals for
the deep space and interstellar missions, so as to meet the requirements for
the seamless autonomous navigation applications from the users on the ground
to the spacecrafts in the near-earth orbits, the deep-space probes and interstellar vehicles, as well as the rovers on the planetary surface without dense
atmosphere.
The 3G-NAV with the space-based TT&C as the core can realize the seamless
signal coverage and navigation application from the ground to near-earth orbit, deep
space and interstellar flight missions, with the technical indicators and performance
features that cannot be achieved in the 2G-NAV system, as follow:
(1) There is the feature of autonomy. The 3G-NAV has the characteristics of
autonomous navigation performance, such as the navigation information
completeness, real-time operability, no emitting signals, no dependence on
the ground stations and long-term automatic operation. Under the BCRF, the
GNSS constellation can operate autonomously for more than 180 days. By
using the reference constellation, the real-time orbit determination accuracies
of the GNSS satellites are better than 10 m, and the time synchronization
accuracies can reach the order of 1 ns.
(2) There is the feature of all space coverage. The third-generation navigation
satellite and pulsar navigation system is suitable for the whole solar system
and the interstellar space outside the solar system, meeting the requirements
for the seamless navigations from the ground to the near-earth space, deep
space and interstellar flight.
(3) There is the feature of the reconfigurable. The third-generation navigation satellite system will realize the constellation, software and hardware, and navigation
signal reconfigurable. The constellation reconfigurable means that the GNSS
satellites are designed by integrating the platform with the payload to get the
compact structure and light weight, and then can be launched on demand and
deployed dynamically to the corresponding station in the constellation, so as to
maintain the constellation formation in time. The software and hardware reconfigurable means that the software is on-orbit programmable, and the hardware
is designed by using the biological evolution algorithms, so as to realize the
performance and function reconfigurable of the payload. The navigation signal
407
requirements for active navigation and high-baud-rate communication in the
deep-space exploration and interstellar flight missions.
(3) The ground support segment is composed of a small number of the GNSS
ground control stations and the radio observation stations, which are responsible for post-processing the orbit and time determination of the GNSS satellites
to evaluate the GNSS performance; integrating the radio and X-ray pulsar data
to build the fundamental database and provide the post-processing service;
as well as regularly dumping and correcting the accumulated model errors of
orbit determination and time synchronization data processing for the reference
constellation satellites.
(4) The navigation application segment consists of the GNSS user terminals on
the ground and in the near-earth space, and the X-ray detector terminals for
the deep space and interstellar missions, so as to meet the requirements for
the seamless autonomous navigation applications from the users on the ground
to the spacecrafts in the near-earth orbits, the deep-space probes and interstellar vehicles, as well as the rovers on the planetary surface without dense
atmosphere.
The 3G-NAV with the space-based TT&C as the core can realize the seamless
signal coverage and navigation application from the ground to near-earth orbit, deep
space and interstellar flight missions, with the technical indicators and performance
features that cannot be achieved in the 2G-NAV system, as follow:
(1) There is the feature of autonomy. The 3G-NAV has the characteristics of
autonomous navigation performance, such as the navigation information
completeness, real-time operability, no emitting signals, no dependence on
the ground stations and long-term automatic operation. Under the BCRF, the
GNSS constellation can operate autonomously for more than 180 days. By
using the reference constellation, the real-time orbit determination accuracies
of the GNSS satellites are better than 10 m, and the time synchronization
accuracies can reach the order of 1 ns.
(2) There is the feature of all space coverage. The third-generation navigation
satellite and pulsar navigation system is suitable for the whole solar system
and the interstellar space outside the solar system, meeting the requirements
for the seamless navigations from the ground to the near-earth space, deep
space and interstellar flight.
(3) There is the feature of the reconfigurable. The third-generation navigation satellite system will realize the constellation, software and hardware, and navigation
signal reconfigurable. The constellation reconfigurable means that the GNSS
satellites are designed by integrating the platform with the payload to get the
compact structure and light weight, and then can be launched on demand and
deployed dynamically to the corresponding station in the constellation, so as to
maintain the constellation formation in time. The software and hardware reconfigurable means that the software is on-orbit programmable, and the hardware
is designed by using the biological evolution algorithms, so as to realize the
performance and function reconfigurable of the payload. The navigation signal