200
4 Navigations from Ground to Space
relative to a certain celestial body in the universe [1]. For the vehicles moving on
land, it is often spoken to travel by cars or drive for journeys, and thus in Chinese, the
character “行” is used more commonly than the character “航”. The terms navigation,
aeronautics and astronautics (or aerospace) are used in the different professional and
technical fields, corresponding to sea voyage, air flight and space flight, respectively.
Therefore, defined from the general technical field, the Navigation (“导航”) refers
to the process of monitoring and controlling the movable object from starting position to the destination in timely, safe and efficient ways according to the scheduled
plans and regulations, and the Voyage refers to the process or activity of moving
and changing the position of movable objects, which means a long journey involving
travel by sea or in space and has close to the connotation of the term “航行” in
Chinese.
Based on the general definition of navigation, an entire navigation process should
include four tasks: to plan the path, to determine the current position, to monitor the
track deviation and to correct the deviation. For the early sea-voyage and air-flight
activities, it is extremely difficult to determine the position of the movable object,
which is usually completed by a professional navigator. By analyzing the real-time
position information of the movable object, the navigator can identify whether the
movable object deviate from the scheduled planning route, the degree of deviation
from the route and the current environment, to determine its states; then, the corresponding measures to correct the route deviation are taken to make the movable
object return to the scheduled route; finally, the movable object can be guided to the
destination safely, efficiently and just in time, according to the plan. In the Chinese
comprehensive dictionary, Cihai, published in Chinese by Shanghai Dictionaries
Publishing House in 1999, the definition of navigation is: “A method and technology
to guide an aircraft or ship from one site to another along a certain route”. With
the application of modern advanced technology like radio navigation, the degree
of automation has been improved increasingly, and the navigator’s work has been
replaced by various navigation systems or taken into account by drivers or pilots. To
complete the navigation task, a key link is that the movable object’s position can be
determined just in time. As a result, the methods and techniques to determine the
positions of the movable objects are customarily referred to as navigation, which is
a special definition for navigation.
There are also the other two terms, “guidance” and “control”, closely associated
with the navigation. The so-called guidance refers to monitoring and guiding the
movable object to the planned route or flying toward the targets based on certain
law, and the so-called control refers to the process and method of adjusting the
deviation between the current position of movable object and the planned route to
make it return to the route. From the general definition, the navigation process should
contain the guidance and control [2]. From the special definition, the navigation
is the fundamental of the guidance and control, and the guidance and control are
the purpose of the navigation, containing and correlating with each other. So, the
navigation, guidance and control systems are often designed in an integrated way
in practical engineering applications. In addition, “positioning” is also another term
related to the navigation. In geodesy, the positioning refers to the technology and
4 Navigations from Ground to Space
relative to a certain celestial body in the universe [1]. For the vehicles moving on
land, it is often spoken to travel by cars or drive for journeys, and thus in Chinese, the
character “行” is used more commonly than the character “航”. The terms navigation,
aeronautics and astronautics (or aerospace) are used in the different professional and
technical fields, corresponding to sea voyage, air flight and space flight, respectively.
Therefore, defined from the general technical field, the Navigation (“导航”) refers
to the process of monitoring and controlling the movable object from starting position to the destination in timely, safe and efficient ways according to the scheduled
plans and regulations, and the Voyage refers to the process or activity of moving
and changing the position of movable objects, which means a long journey involving
travel by sea or in space and has close to the connotation of the term “航行” in
Chinese.
Based on the general definition of navigation, an entire navigation process should
include four tasks: to plan the path, to determine the current position, to monitor the
track deviation and to correct the deviation. For the early sea-voyage and air-flight
activities, it is extremely difficult to determine the position of the movable object,
which is usually completed by a professional navigator. By analyzing the real-time
position information of the movable object, the navigator can identify whether the
movable object deviate from the scheduled planning route, the degree of deviation
from the route and the current environment, to determine its states; then, the corresponding measures to correct the route deviation are taken to make the movable
object return to the scheduled route; finally, the movable object can be guided to the
destination safely, efficiently and just in time, according to the plan. In the Chinese
comprehensive dictionary, Cihai, published in Chinese by Shanghai Dictionaries
Publishing House in 1999, the definition of navigation is: “A method and technology
to guide an aircraft or ship from one site to another along a certain route”. With
the application of modern advanced technology like radio navigation, the degree
of automation has been improved increasingly, and the navigator’s work has been
replaced by various navigation systems or taken into account by drivers or pilots. To
complete the navigation task, a key link is that the movable object’s position can be
determined just in time. As a result, the methods and techniques to determine the
positions of the movable objects are customarily referred to as navigation, which is
a special definition for navigation.
There are also the other two terms, “guidance” and “control”, closely associated
with the navigation. The so-called guidance refers to monitoring and guiding the
movable object to the planned route or flying toward the targets based on certain
law, and the so-called control refers to the process and method of adjusting the
deviation between the current position of movable object and the planned route to
make it return to the route. From the general definition, the navigation process should
contain the guidance and control [2]. From the special definition, the navigation
is the fundamental of the guidance and control, and the guidance and control are
the purpose of the navigation, containing and correlating with each other. So, the
navigation, guidance and control systems are often designed in an integrated way
in practical engineering applications. In addition, “positioning” is also another term
related to the navigation. In geodesy, the positioning refers to the technology and