CN115097712B

CN115097712B - Time unification method and time user system based on pulsar sequence number rule

Info

Publication number: CN115097712B
Application number: CN202210482311.0A
Authority: CN
Inventors: 刘民
Original assignee: Beijing Dongfang Measurement and Test Institute
Current assignee: Beijing Dongfang Measurement and Test Institute
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2024-01-26
Anticipated expiration: 2042-05-05
Also published as: CN115097712A; WO2023213111A1

Abstract

The application discloses a time unification method and a time user system based on pulsar sequence number rule, wherein the method comprises the following steps: creating a wide area inertial coordinate system, wherein the agreed coordinate origin is a space-time reference point, and is called a wide point for short; assigning consistent initial epochs to a plurality of pulsars; based on the initial epoch, for pulse signals with the same serial number of the same pulsar, under the condition of measurement by different observers, the time of reaching the wide point converted into the visual angle of the wide point observer is the same; the space time keeping subsystem broadcasts pulse sequence number information, and transmits initial epoch in the space-time span of one pulse period, or inherits the initial epoch agreed by the existing space time keeping subsystem; and implementing a feedback adjustment mechanism of the space time keeping subsystem according to the pulse sequence number information. The method is a part of unified rules of time outside the earth, and is suitable for other celestial bodies and spacecrafts outside the earth.

Description

Time unification method and time user system based on pulsar sequence number rule

Technical Field

The embodiment of the application relates to a time metering technology, in particular to a time unification method and a time user system based on a pulsar sequence number rule.

Background

The science of China has selected a ten-year-front science problem of 2021, in which "is there a unified time rule outside the earth? "consider that the time rule on earth cannot be applied to the vast space of the universe, and propose the space time keeping system is a method of setting up a unified time when the coordinate is reproduced with an atomic clock and when the coordinate is reproduced with a pulsar on the centroid coordinate system of the solar system. The paper "space time keeping system concept research" (DOI: 10.13382/j. Jemi.B 2104152) published in the journal of electronic measurement and instrumentation (4 months of 2021), and the Chinese patent application published in the name of CN111665709A and published in the date of 2020, 9 months and 15 days, details the principle and implementation method of the space time keeping system, but does not further explain how to agree on the initial epoch of a pulsar, how to implement the time unification between different space time keeping subsystems based on the sequence number rule of the pulsar, and does not relate to the problem of how to use the time rule by users.

Due to the influence of relativistic effects, simultaneity is defined only in the same coordinate system, and the original time cannot be directly compared without simultaneity between different coordinate systems. For unifying the time, a common coordinate system, namely a wide area inertial coordinate system, is selected, the time at the origin and infinity point of the wide area inertial coordinate system is the basis of the unification time in the whole domain, and the pulse signal sent by the pulsar is regarded as the signal at infinity coordinate. How to use remote pulse signals to realize the time unification of the whole potential range (or "whole domain") is a problem to be solved at present. The current pulsar observation technology comprises ground radio astronomical observation and X-ray detector observation on a spacecraft, namely, a pulsar with stable pulse period can be selected as a time frequency reference standard. However, how to make observers (or called time keeping subsystems) on two different local coordinate systems realize pulsar-based time unification has no prior technical scheme for reference.

Disclosure of Invention

In view of this, the embodiments of the present application provide a method and a time user system for unifying time based on pulsar sequence number rule.

According to a first aspect of the present application, there is provided a method for unifying time based on pulsar sequence number rule, comprising:

in the inertial reference system, a wide-area inertial coordinate system is created, and the mass center of all the masses in the gravitational potential range (or in the global domain) is set as a coordinate origin, which is hereinafter referred to as a "wide point"; wherein, the observers in the wide area inertial coordinate system at least comprise a space time keeping subsystem and a time user system; the wide point is a spatial reference point of all observers, the attraction at the wide point is zero, and the observer speed at the wide point is zero; the viewer at the broad point is a broad point viewer; for all observers, the pulsar pulse signal and corresponding pulsar received by the wide-point observer has the following stable characteristics: pulsar azimuth, pulse period, and pulse profile;

the method has the advantages that consistent initial epochs are appointed for a plurality of pulsars, and the consistency requirement of the pulsar sequence number rule is met; the consistency requirement is that the time to reach the wide point converted into the visual angle of the wide point observer is the same under the condition of measurement by different observers for pulse signals with the same serial number of the same pulsar based on the initial epoch;

The space time keeping subsystem broadcasts pulse sequence number information, and transmits the initial epoch in the space-time span of one pulse period, or inherits the initial epoch agreed by the existing space time keeping subsystem;

and implementing a feedback adjustment mechanism of the space time keeping subsystem according to the pulse sequence number information.

As an implementation manner, the pulsar pulse signal and the corresponding pulsar received by the wide-point observer have the following stable characteristics: pulsar azimuth, pulse period, and pulse profile, including:

the pulsar azimuth is azimuth acceptance or appointed azimuth; the pulse period is a period acceptance or agreement period; the pulse profile is a pulse profile acceptance or contract profile;

wherein the azimuth of a pulsar refers to an angular coordinate vector in the wide area inertial coordinate system, and is agreed by all observers; obtaining the projection distance of the observer on the certain pulsar azimuth by the dot product of the unit vector of the angular coordinate vector and the coordinate of the observer; wherein, the dot product is a vector operation rule; in the direction from the wide point to the certain pulsar, the pulse signal passes through or reaches a viewer in the form of plane electromagnetic wave, and also passes through or reaches the wide point, wherein the projection distance between the viewer and the wide point in the direction accords with a two-dimensional space-time relationship with the time difference when the plane electromagnetic wave of the same pulse signal passes through the coordinates of the viewer and the wide point successively, namely delta t=d/c, wherein delta t is the time difference expressed when the coordinates is expressed in terms of SI seconds of international units; d is the projection distance of the observer in the direction of the pulsar, and the unit is SI meters; c is the speed of light.

As an implementation manner, the pulse periods of the plurality of pulsars have an aggregate stability, where the aggregate stability criterion of the pulse periods includes:

the agreed pulse period of the pulsar is a consistent constant for all observers, and the unit is SI seconds; the set stability refers to a phenomenon that pulse sequence numbers of a plurality of pulsars received from the wide-point observer and pulse periods are kept in a certain proportion relation, the pulse sequence numbers refer to continuous pulse numbers sent by the pulsars after an initial epoch, and for k pulsars, a set stability expression is as follows:

t _oSSB ＝n ⁽¹⁾ T ₁ -p ₁ +q ₁ (t)＝n ⁽²⁾ T ₂ -p ₂ +q ₂ (t)＝…＝n ^(k) T _k -p _k +q _k (t) (1)

in formula (1), k=1, 2,..represents a plurality of pulsars named or numbered 1,2,..k; t is t _oSSB For the coordinates at the wide point, the unit is SI seconds; n is n ^(k) A sequence number indicating that the pulsar pulse designated k reaches the wide point, an upper corner mark ^(k) The designation; t (T) _k The unit is SI seconds which is the period of the pulsar; p is p _k The initial phase of the pulsar pulse profile; q _k (t) is at t _oSSB Time difference between time and time when the integer pulse reaches the wide point, when n ^(k) Q when an integer carry event occurs _k (t) =0, and q _k (t)<T _k The unit is SI seconds;

the set of stability criteria includes: if the named pulsar numbers k=1, 2, … k are ordered by pulse period size, for example: t (T) ₁ ≤T ₂ ≤…≤T _k Maximum allowable deviation epsilon is respectively set for 2-k pulsars ₂ 、ε ₃ 、...、ε _k Forming a criterion array on the right of the inequality sign in the inequality (4), wherein NC represents no criterion, and if one element of a triangle matrix under the left in the criterion array in the inequality (4) does not meet the inequality condition, adjusting the period of a pulsar corresponding to the element which does not meet the condition or removing the period from a pulse period set;

as one implementation, the pulse profile is a pulse profile acceptance or contract profile comprising:

the pulse profile of the pulsar refers to a profile of each pulsar with its own characteristics, wherein the own characteristics of the pulsar comprise shape characteristics on amplitude and phase characteristics on time;

the initial phases of the pulse contours of the wide-point observers are consistent, and the phase waveforms of specific radiation spectrum segments are agreed; all observers change the coordinate axes of time, and the pulse profile expressed by the coordinate of the wide-point observer is changed into a consistent pulse profile.

As one implementation, the transfer of the pulsar initial epoch from the space-time keeping subsystem to the viewer may be accomplished by broadcasting and receiving the pulse sequence number information.

The pulse sequence number information broadcast by the space-time keeping subsystem comprises at least one of the following:

Pulsar name k, pulse sequence number n ^(k) The time of the pulse reaching the wide point is the pulse origin time t _nk The method comprises the steps of carrying out a first treatment on the surface of the Space-time keeping subsystem x as broadcaster, when space-time keeping subsystem x receives pulse sequence number n ^(k) The projection distance d to a wide point _xk Delay time t of signal processed by space time keeping subsystem x _dx ；

The initial epoch of the pulsar is all pulsars which are identified or agreed by the space time keeping subsystem, the time when the pulse with the sequence number of zero reaches a wide point is zero, the value at the coordinate is zero, and the initial phase is the difference between the starting point of the pulse profile and the origin of the time axis. For a viewer newly joining a space-time keeping system, such as a new space-time keeping subsystem, or a time user system, a transfer or inheritance process is required to obtain the agreed initial epoch of the pulsar at one time, so that the initial epoch (or the time axis origin, or the time zero point) in the coordinates of the initial epoch is unified with other space-time keeping subsystems.

Delivering the initial epoch to the viewer by the space conservation subsystem, specifically comprising:

the time difference of adjacent integer serial numbers of the pulse is a pulse period interval; in the space-time range of one pulse period interval, the observer b receives the pulse sequence number information sent by the space time keeping subsystem a, if the sum of the information processing delay and the space transmission delay is deltat _s Less than pulse period T _k T, i.e _k >Δt _s Viewer b receives the pulse sequence number signalAfter the rest, the delay time delta t can be calculated from the observation result of the pulse event _s And translating the time axis when the coordinates are translated, so as to realize the transmission of the initial epoch from the space conservation subsystem a to the observer b. Specifically, the pulse event refers to the time when the pulse signal of the pulsar reaches the broad point and the corresponding serial number, and is expressed as: events (sequence number, time), non-wide-point observers need to be calculated to obtain pulse events; viewer b inherits the pulse event (n) of pulsar named k from the pulse sequence number information of space-time subsystem a ^(k) ,t _ank ) The inheritance means that the observer b designates the event sequence number of the pulsar named k as n ^(k) The corresponding time is assigned t _abnk Then, the observer b observes for a period of time, b measures and calculates the next pulse event (n ^(k) +1,t _bnk ) Because T should be within a pulse period space-time range _k ≥(t _bnk -t _abnk ) The equal sign holds if and only if the initial epoch of observer b and space conservation subsystem a are the same, due to Δt _s ＝t _abnk -t _ank Further denoted as t _bnk -t _abnk ＝(T _k -Δt _s ) Wherein t is _bnk Is the observation of observer b, t _abnk Is inherited by viewer b and is equal in value to t _ank ，T _k Is a known parameter of the pulsar database, thus the delay delta t _s Can be calculated. Then, by shifting the time axis at the time of the coordinates of b, the delay Δt of the pulse sequence number information is eliminated _s The effect of (a) is to make the initial epoch of b and a identical, i.e. t _bnk ＝t _ank +T _k 。

The time axis of the translation coordinate means that a viewer modifies the observed pulse event (n ^(k) +1、t _bnk ) Time t of (a) _bnk Let t _bnk ＝t _ank +T _k ＝t _abnk +(T _k -Δt _s ) At the same time, modifying the sequence number n in the pulse event of the other pulsar named j ^(j) To satisfy the requirement of inequality (4), then n' ^(j) ＝n ^(j) +[(T _k -Δt _s )/T _j ]Wherein n is ^(j) And n' ^(j) The serial numbers, T, of the pulsars named j before and after the translation of a viewer _j Is the period of pulsar j, (T) _k -Δt _s ) Translation in coordinates, []Is a truncated integer operator;

alternatively, the inheriting the initial epoch agreed by the existing space conservation subsystem includes: the method is realized by a coordinate axis translation mode: within the space-time span of a cycle, the same pulse signal of the same pulsar observed by the space-time subsystem a and the observer b reaches the wide point, the pulse event (n ^(k) 、t _nk ) The method is unique, and the process of inheriting the initial epoch is only carried out once, so that the consistent and agreed initial epoch can be obtained; the events referenced by the space conservation subsystem a and the observer b are not limited to pulse events, but also comprise known events agreed by the two parties, and the known events comprise bidirectional electromagnetic wave signals.

As an implementation manner, implementing a feedback adjustment mechanism of the space-time keeping subsystem according to the pulse sequence number information includes:

the pulse sequence number information broadcast by the space time keeping subsystem and the pulse sequence number information received by all observers form a first database;

the observer judges whether the pulse event is abnormal, and when the pulse event is abnormal, the initial epoch of the coordinate axis in coordinate adjustment is abnormal by a method of translating the time axis in coordinate adjustment, and the translation quantity is the pulse period T of the pulsar _x Integer multiples of (2);

adjusting the orbit parameter calendar of the observer to enable the time deviation of the pulse event to be converged to be less than +/-0.5T _x 。

As one implementation manner, the observer judges whether the pulse event is abnormal, and in the case of the pulse event abnormality, adjusts an initial epoch elimination abnormality of a coordinate axis at the time of the coordinate by a method of translating the time axis at the time of the coordinate, including:

configuring at least three space time keeping subsystems, independently measuring a plurality of pulsars to obtain a pulse event, and broadcasting pulse sequence number information to other observers based on the obtained pulse event;

the observer receives the pulse sequence number information broadcast by the at least three space time keeping subsystems and generates a first data table which is classified by pulse stars and takes the pulse sequence number as an index; wherein the leftmost column of the first data table is a pulse sequence number, and different columns of the same row are time information in pulse events from each space-time subsystem; a portion of the cells in the first data table allow no data items;

According to the consistency requirement of the initial epoch and the sequence number rule of the pulsar, the time measured by the same pulse event for different observers is the same, and the time measured by the same row of pulse sequence numbers in the first data table and different space time keeping subsystems should be the same theoretically, which is also called a consistency criterion;

each observer checks the difference between the time in the pulse event and the time average value in the pulse event of other space daemon subsystems, and if the difference exceeds one pulse period, the initial epoch is adjusted, and the coordinate axis in coordinate translation is adjusted, so that the time in the pulse event of the observer is consistent with the average value; the time difference of the space time keeping subsystem participating in the average value calculation on the same pulse event is smaller than or equal to the period of the pulsar corresponding to the pulse; if the time difference value of the space time keeping subsystem participating in the average value calculation on the same pulse event is larger than the value of the pulse star period corresponding to the pulse star or larger than a set threshold value, adopting a few rule obeying majority, calculating a time average value after eliminating the space time keeping subsystem with the largest deviation, and adjusting the initial epoch of a time coordinate axis by the redetermined time average value; or taking time in a pulse event observed on earth as a reference;

In the first data table, the observer checks whether the pulse event of the long-period pulsar is abnormal or not preferentially, and then checks the pulse event of the short-period pulsar, so that the difference between the time and the time average value of the observer under the same sequence number within a certain allowable deviation range is smaller than one pulse period T _x Is not limited.

As one implementation, the method adjusts the orbit parameter calendar of the observer to bias the time of the pulse eventThe difference converges to less than + -0.5T _x Comprising:

if at least one revolution orbit period is subjected to feedback adjustment, each space time keeping subsystem can ensure that the time of the same sequence number row is within a certain allowable deviation range in a table row corresponding to the pulse sequence number of each pulsar in the first data table, and meets a consistency criterion; for the space timekeeping subsystem exceeding the allowable deviation, adjusting the local track parameter calendar to reduce the time deviation;

the local track parameter calendar plays a regulating role in the following two calculation processes:

calculating a local to wide-point delay time by using the track position parameters, and giving a wide-point time for the pulse event; and

in the pulse profile measurement process, local orbit parameters are used when transforming from original to coordinates.

As an implementation, the method further includes:

each space-time keeping subsystem holds the same pulsar database, which is a collection of a plurality of pulsar ephemeris including at least one of the following information: pulsar name, azimuth vector of pulsar, pulsar pulse contour, initial phase of pulsar contour, zero-phase model of pulsar contour, pulsar pulse period, correction value of pulsar period and correction value of initial phase;

each space time keeping subsystem checks the own pulse sequence number information database and generates a second data table which is classified by the space time keeping subsystem and takes the coordinate time as an index, wherein the leftmost column of the second data table is the coordinate time of a local observer, and different columns of the same row are integer sequence numbers of different pulsars at the moment; and taking the serial number of the same row as the input of the set stability criterion inequality (4), and calculating the matrix difference at the left side of the inequality (4) to obtain the set stability deviation.

According to a second aspect of the present application, there is provided a system for the time user comprising: the system comprises an in-situ measurement device, a pulsar measurement device, a device for receiving broadcast information, a local track parameter calendar, a pulse sequence number information database and a pulse sequence number rule;

The local track parameter calendar includes at least one of: a local position vector, a local speed vector and a local force potential which take a local original time as an index and take a wide point as a reference;

the time-of-day measuring device is used for obtaining local time-of-day;

the pulsar pulse measuring device is used for observing the pulse profile of the pulsar according to the local original time, and calculating the projection distance delay time by using the local orbit parameter calendar when the coordinates of the moment when the pulse of the pulsar reaches the local time are obtained, so that the wide-point time is obtained.

As an implementation manner, the time user system has the same hardware and software configuration as the space-time keeping subsystem except that the time user system cannot broadcast pulse sequence number information;

the time user system is also used for receiving the pulse sequence number information broadcast by the space time keeping subsystem, and updating the initial epoch of the coordinate axis of the time user system according to the pulse sequence number information broadcast by the space time keeping subsystems, the pulsar database and the pulse sequence number information database.

According to the embodiment of the application, the wide area inertial coordinate system is established by defining the coordinate origin of the wide area inertial coordinate system, the pulse signals of the pulsar are observed through the space time keeping subsystem, and the pulse sequence number information is broadcast based on the observation result, so that the transmission or succession of the initial epoch is realized; and the other space time keeping subsystems execute feedback adjustment according to the pulse sequence number information. The embodiment of the application realizes the rule of contract in the time rule outside the earth and the application thereof, provides a unified time method suitable for the whole domain, and can be applied to communication, calendar and the like of the whole domain. The time rule provided by the embodiment of the application is a part of a unified rule of time outside the earth, is suitable for other celestial bodies and spacecrafts outside the earth, and meets various requirements of independently measuring time without depending on time service signals on the earth.

Drawings

Fig. 1 is a flowchart of a method for unifying time based on pulsar sequence number rule according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing the set stability expression of the initial epoch and period of pulsar according to the embodiment of the present application;

FIG. 3 is a schematic diagram of a relationship between a space-time keeping subsystem a and a viewer b without considering the quantized pulse interval in accordance with an embodiment of the present application;

FIG. 4 is a diagram of a relationship between a time keeping system A and a viewer B considering a quantized pulse interval situation according to an embodiment of the present application;

FIG. 5 is a diagram of data indexed by pulse sequence number of a pulsar classification according to an embodiment of the present application;

FIG. 6 is a diagram of data representative of the classification of pulsars according to an embodiment of the present application;

fig. 7 is a schematic diagram of a composition structure of a time user system according to an embodiment of the present application.

Detailed Description

Because observers in different coordinate systems use their own local time as reference, when measuring pulse signals of the same pulsar, different pulse periods and pulse signal contours are obtained, and a solution is given in the Chinese patent application with publication number of CN111665709A for this problem, in which each observer transforms measurement data onto the origin of the wide-area coordinate system, applies Doppler effect time axis transformation, relativistic effect time axis transformation and other algorithms, and converts the data measured by each observer in situ into data expressed by coordinates on the origin. These scaling processes are also the basis of the embodiments of the present application, and the related technical solutions in the chinese patent application with publication No. CN111665709a should not be interpreted as inadequate disclosure if no careless or careless description is made in the embodiments of the present application. The rules discussed in the embodiments of the present application are based on the chinese patent application publication No. CN111665709a, where each observer converts the measurement result into the measurement result of the observer at the origin position of the wide-area coordinate system.

To assist those skilled in the art in understanding the following terms are reiterated in the examples of this application:

1. the viewer: a surveyor at a specific location, the specific location including, for example, the origin of the coordinate system; and the location of the space conservation subsystem, the local conservation system, the time user system and the like.

2. Wide area inertial coordinate system: the reference direction is a stable, non-rotating coordinate system with the origin of coordinates agreed by all observers.

3. Contract and agree: in the embodiment of the application, the meaning of the agreement is similar to that of the agreement, the agreement between the judgment formed by self-cognition and other people is the agreement, and the conclusion of the agreement according to a specified method is the agreement, when the self-cognition of a plurality of subjects is the same, the two can be replaced with each other.

4. Broad spot: origin of wide area inertial coordinate system. The viewer at the origin is called a wide-point viewer.

5. Pulse sequence number: the wide-point observer continuously records pulses reaching the wide point, and is given continuous and uninterrupted integer numbers, and the serial numbers from different pulsars are unique and monotonically increasing.

6. Initial epoch: inherits the definition of the Chinese patent application with publication number CN111665709A, and the initial epoch is when the pulse with the serial number of 0 reaches the coordinates of the wide-point moment.

7. Space time keeping subsystem: the system refers to a local time keeping system in the space time keeping system in the Chinese patent application with the publication number of CN111665709A, which is called a subsystem for short, mainly considers that the meaning expressed by the local time keeping system is applicable to a coordinate system and space distribution, the subsystem in the embodiment of the application is applicable to the relation between a description part and the whole, the space distribution is not concerned, the two components are identical, and three or more subsystems can form the space time keeping system through broadcast feedback.

8. Pulse event: the combination of the pulse sequence number and the time is that a viewer measures one pulse of the pulsar and calculates the time of reaching a wide point, and the sequence number and the time of the pulse form a pulse event. The impulse event is the result of an individual measurement by a viewer, which may be different for different viewers.

9. Pulse sequence number information: information broadcast by the space conservation subsystem to the wide area space is unique. Pulse sequence number information includes, but is not limited to: pulsar name, pulse sequence number, pulse origin time, space time keeping subsystem name for transmitting the information, projection distance from space time keeping subsystem to wide point, delay time of processing signal, etc.

10. Pulse sequence number information database: each observer independently measures the pulse event, and receives the pulse sequence number information broadcast by other space time keeping subsystems to form an information set.

11. Pulsed ephemeris: the definition of the Chinese patent application with publication number of CN111665709A is inherited, and the pulsar ephemeris comprises pulsar names, azimuth vectors of pulsars, pulse profiles of the pulsars, initial phases of the pulse profiles, zero-phase models of the pulse profiles, pulse periods of the pulsars, correction values of the pulse periods and correction values of the initial phases.

12. Pulsar database: a collection of agreed upon multiple pulse ephemeris is broadcast, maintained at each spatial time keeping subsystem and time user.

13. Time user system: the system is a user using a space time keeping system, the user system receives rules and receives broadcast pulse sequence number information, the unified time measurement can be realized, and other hardware, software and methods are the same as a space time keeping subsystem except that the time user system does not have the authorization of the broadcast pulse sequence number information.

Fig. 1 is a flowchart of a method for unifying time based on a pulsar sequence number rule according to an embodiment of the present application, as shown in fig. 1, where the method for unifying time based on a pulsar sequence number rule according to an embodiment of the present application includes the following processing steps:

In step 101, in the inertial reference system, a wide area inertial coordinate system is created, and the centroid of all the masses in the gravitational potential range or the full range is set as the origin of coordinates.

Hereinafter, the origin of the wide area inertial coordinate system coordinates is simply referred to as "wide point"; wherein, the observer of the wide area inertial coordinate system at least comprises a space time keeping subsystem and a time user system; the wide point is a spatial reference point of all observers, the attraction at the wide point is zero, and the observer speed at the wide point is zero; the observers at the wide points are wide-point observers; for all observers, the pulsar pulse signal and corresponding pulsar received by the wide-point observer has the following stable characteristics: pulsar azimuth, pulse period, and pulse profile.

Step 102, agreeing an initial epoch for a plurality of pulsars to meet the requirement of consistency of the pulsar sequence number rule; based on the initial epoch, the time to reach the wide point converted into the viewing angle of the wide point observer is the same for the same serial number of pulse signals of the same pulsar, as measured by different observers.

Step 103, the space time keeping subsystem broadcasts pulse sequence number information, and transmits the initial epoch in the space-time span of one pulse period or inherits the initial epoch agreed by the existing space time keeping subsystem.

And 104, implementing a feedback adjustment mechanism of the space time keeping subsystem according to the pulse sequence number information.

The time rule provided by the embodiment of the application is a part of a unified rule of time outside the earth, is suitable for other celestial bodies and spacecrafts outside the earth, and meets various requirements of independently measuring time without depending on time service signals on the earth.

The specific implementation of each of the above steps is explained in detail below in conjunction with specific examples.

The embodiment of the application defines a coordinate origin (wide point) of a wide-area inertial coordinate system, wherein the wide-area inertial coordinate system comprises all local coordinate systems in a space range covered by a uniform time, and the wide point has three characteristics, namely, the origin is identified by observers in all coordinate systems, is objectively existing and fixed in position, and is a reference point of time and space of all observers; secondly, the force potential at the origin is zero; third, the viewer speed at this origin is zero, i.e., itself is stationary relative to itself.

Pulsars have three characteristics and also require acceptance by all observers. Pulsars are numerous, but the pulsar selected as the reference standard should have three characteristics that are recognized by all observers, namely, azimuth recognition or contracted azimuth; secondly, period acceptance or contract period; finally, pulse profile acceptance, or contract profile, is used.

The orientation of a particular pulsar in the agreement is consistent and identical for all observers to agree on the angular coordinate values in the wide area inertial coordinate system. In the direction from the wide point to the pulsar, the pulsed electromagnetic signal sweeps (or arrives) the observer in the form of planar electromagnetic wave, and also sweeps (or arrives) the wide point, wherein the projection distance of the observer and the wide point in the direction accords with the two-dimensional space-time relationship with the time difference when the observer and the wide point sweep coordinates of the same pulse successively, namely delta t=d/c, wherein delta t is the time difference expressed when the coordinates is SI seconds; d is the projection distance of the observer in a certain pulsar direction, and the unit is m; c is the constant of the speed of light.

The period of the agreed pulsars is a constant that is stable for all observers in SI seconds. The set stability refers to a phenomenon that the proportional relation between the pulse sequence numbers and the pulse periods of a plurality of pulsars received from a wide-point observer is kept to be certain, and specifically, for k pulsars, the set stability expression is as follows:

wherein: k=1, 2..a. Means that the designation or number 1,2, multiple pulsars of k; t is t _oSSB When the coordinates are the coordinates of a wide-point observer, the unit is SI seconds; n is n ^(k) The sequence number of pulse star pulse reaching wide point is natural number, and is marked with an angle ^(k) The representation names, not the exponential function; t (T) _k The period of pulsar named k is given in SI seconds; p is p _k The initial phase of the pulsar pulse profile, designated k, is given in SI seconds; q _k (t) is at t _oSSB The time difference between the same instant and the instant when the integer pulse of pulsar named k has reached the wide point is n ^(k) Q when carry event occurs _k (t) =0, and not greater than 1 period value, i.e. q _k (t)<T _k The unit is SI seconds; the graphical representation of equation (1) is shown in fig. 2.

When the initial epoch is fixed, at a certain time, such as t _oSSB At the moment of time, each n is compared ^(k) If the named pulsar numbers are ordered according to the pulse period, the number is as follows: t (T) ₁ ≤T ₂ ≤…≤T _k The ratio of the sequence numbers, e.g. n ⁽²⁾ /n ⁽¹⁾ Or n ^(k) /n ⁽¹⁾ Approximating the ratio of pulse periods, e.g. T ₁ /T ₂ Or T ₁ /T _k The larger the sequence number is n ⁽¹⁾ The smaller the initial phase and full period phase difference effects.

Set stability requirement when sequence number n ⁽¹⁾ When sufficiently large, the ratio of the contracted periods is such as T ₁ /T ₂ Or T ₁ /T _k Ratio to sequence number observed at a broad point, e.g. n ⁽²⁾ /n ⁽¹⁾ Or n ^(k) /n ⁽¹⁾ The difference being less than a prescribed value, e.g. 2/n ⁽¹⁾ Otherwise, the pulsar should be replaced, the pulsar which does not meet the requirement is removed from the pulsar set, replaced by a new pulsar, or the period of the pulsar is contracted again.

The set stability criterion, if the named pulsar numbers k=1, 2, … k are ordered according to the pulse period size, is as follows: t (T) ₁ ≤T ₂ ≤…≤T _k Maximum allowable deviation epsilon is respectively set for 2-k pulsars ₂ 、ε ₃ 、...、ε _k And (3) forming a criterion array on the right side of the inequality sign in the inequality (4), wherein NC represents no criterion, and if one element of the triangle matrix on the lower left in the criterion array in the inequality (4) does not meet the inequality condition, the pulsar represented by the row needs to be adjusted in period or removed from the pulse set. This is called "set stability", and represents the overall stability of the set of reference pulsars.

The agreed profile of pulsar means that each pulsar has a unique pulse profile, and the pulse profile has shape characteristics in amplitude and phase characteristics in time, and the definition of the pulse profile is the same as that of the Chinese patent application with publication number of CN111665709A, and is not repeated here. It is well recognized to all observers that a broad-point observer can obtain a stable initial phase of the pulsar pulse profile, as well as a phase waveform at a particular radiation spectrum. The pulse profile similarity is not equivalent to the amplitude equality of the waveforms, but the maximum correlation coefficient is obtained in the correlation calculation. That is, the measured pulse profile may be different for different observers due to relativistic effects, but the pulse profile expressed by coordinates of a wide-point observer is recognized by all observers through time coordinate axis transformation, and the coordinate axis transformation method and the similar calculation method can refer to the chinese patent application publication No. CN111665709 a. The emphasis placed on the contracted condition in the embodiments of the present application is that only a wide range of observers can obtain a stable profile.

In this embodiment, the initial epoch of the pulsar is a corresponding point on the time axis when the pulse sequence number and the coordinates are recognized by all observers, and the transmission mode of the initial epoch refers to that the initial epoch of the existing space-time keeping subsystem is transmitted to the newly added space-time keeping subsystem or the time user system.

The pulse sequence number information broadcast by the space time keeping subsystem comprises { TNx } = { pulsar name k; pulse sequence number n ^(k) The method comprises the steps of carrying out a first treatment on the surface of the The time of arrival of the pulse at the broad point (also referred to as the pulse origin time) t _nk The method comprises the steps of carrying out a first treatment on the surface of the A broadcast space time keeping subsystem name x; when space conservation subsystem x receives pulse sequence number n ^(k) The projection distance d to a wide point _xk The method comprises the steps of carrying out a first treatment on the surface of the Delay time t of processing signal of space time keeping subsystem _dx Information, x represents different spatial time keeping subsystem publishers. And the observer receiving the broadcast adjusts the initial epoch of the observer according to the information, or the time axis when the coordinate is shifted is consistent with the initial epoch of the transmitting subsystem.

FIG. 3 shows a space-time subsystem a according to an embodiment of the present application, which does not consider the quantized pulse intervalAs shown in fig. 3, the space-time keeping subsystem a is a representation of a plurality of space-time keeping subsystems which agree with the initial epoch, the space-time keeping subsystem a sends out a broadcast, the broadcast message contains pulse sequence number information { TNa }, the latest and recently sent pulse sequence number information { TNa } is received by the observer b, and the observer b should be from the latest space-time keeping subsystem, based on the received pulse sequence number information { TNa }, initializes the coordinate axis (vertical axis, unit: number in fig. 3) and time coordinate axis (horizontal axis, unit: SI seconds in fig. 3) corresponding to the pulse sequence number of the observer b to be the sequence number and time consistent with { TNa }, and continuously measures each subsequent pulse event (sequence number-time) (to obtain a relationship oblique line n of pulse sequence number and time indicated by the bold line in fig. 3) ^(k) -t). Ideally, the pulse sequence number and the slope n expressed in coordinates are not considered in quantifying the pulse interval ^(k) -T, slope 1/T _k Extend reversely to n ^(k) When=0, then t=0, which is the initial epoch of viewer b, and back-pushing the initial epoch will find out that the initial epoch of viewer b differs from the initial epoch of space conservation subsystem a by |t _ank -t _bnk I, mainly due to the spatial delay time of the transmitted signal.

In practice, however, the pulse sequence number information is quantized, the time difference between adjacent sequence numbers should be a whole pulse period interval, if the space conservation subsystem a and the observer b are within the space-time range of one pulse period interval, the pulse information processing is delayed by the time t _da And the sum of the spatial distance delay times Deltat _s ＝t _da +|t _ank -t _abnk I, less than pulse period T _k T, i.e _k >Δt _s Then the observer b inherits the pulse sequence number information { TNa } of the space-time keeping subsystem a, independently measures, calculates the delay, and translates the time axis (T _k -Δt _s ) After eliminating the effect of the delay, the delay will be reduced after the pulse event (n ^(k) +1、t _bnk ) Consistent with the initial epoch of space-time keeping subsystem a, i.e., t _bnk ＝t _ank +T _k . Wherein the time axis of the translation coordinate is the time axis when a viewer modifies the observed pulse event (n ^(k) +1、t _bnk ) Time t of (a) _bnk Let t _bnk ＝t _ank +T _k ＝t _abnk +(T _k -Δt _s ) Wherein (T) _k -Δt _s ) Is the magnitude of translation, t _bnk And t _abnk Is the observation of viewer b, T _k Is a known parameter of a pulsar database; at the same time, the sequence number n in the pulse event of other pulsar named j is modified ^(j) To satisfy the requirement of the formula (4), n' ^(j) ＝n ^(j) +[(T _k -Δt _s )/T _j ]Wherein n is ^(j) And n' ^(j) The serial numbers, T, of the pulsars named j before and after the translation of a viewer _j Is the period of pulsar j, (T) _k -Δt _s ) Translation in coordinates, []Is a truncated integer. That is, the same pulse of the same pulsar is observed by the space-time subsystem a and the observer b to reach a broad point within a whole-period space-time span, its pulse event (n ^(k) 、t _nk ) And if the space distance between the space time keeping subsystem a and the observer b is increased, the pulsar with larger period is required to provide reference, the process of inheriting the initial epoch is carried out once, the consistent initial epoch can be obtained, and the subsequent continuous measurement pulse is not transmitted again. For pulsar with longer pulse period, the measurement error is larger, so that the subsequent feedback adjustment is needed. Of course, as an implementation, initial epoch consistency may also be achieved with the aid of pulsars of shorter pulse periods.

This process is transitive to more space-time subsystems, namely, space-time subsystem a is transited to observer b, and observer b is transited to space-time subsystem C, so that space-time subsystem a and space-time subsystem C also have the same initial epoch.

To achieve the coincidence of the initial epoch, the events that the space conservation subsystem a and the observer b can refer to are not limited to pulsars with long periods, but can be known events agreed by both parties, such as bidirectional electromagnetic wave signals.

FIG. 4 is a timing system for taking into account quantized pulse interval conditions according to an embodiment of the present applicationA and viewer B are schematically related, as shown in FIG. 4, the space-time subsystem A observes the nth pulsar, designated k ^(k) The time t when the pulse reaches a wide point is calculated according to the method given in the Chinese patent application with publication number of CN111665709A _Ank Obtaining pulse events (n ^(k) ，t _Ank ) Looking up local orbit parameter calendar table to obtain projection distance d from space time keeping subsystem A to wide point _Ak The space time keeping subsystem A delays t _dA After time, broadcasting the broadcasting pulse sequence number information { TNA } = { k; n is n ^(k) ；t _Ank ；A；d _Ak ；t _dA The method comprises the steps of carrying out a first treatment on the surface of the .., the broadcast information is delayed by a spatial transmission delay t } _ds Then, the pulse event is received by the observer B, the observer B inherits the pulse event of A, and the pulse event is recorded as t on the time coordinate axis of B at the moment _ABnk Equal in value to t _Ank Viewer B independently measures the nth pulsar, designated k ^(k) +1 pulses, obtain pulse events (n ^(k) +1，t _Bnk )，t _ABnk And t _Bnk Are observable points of the B coordinate axes of the observers, and if A and B are in a whole period space-time range of a pulsar named as k, T should be satisfied _k ≥(t _Bnk -t _ABnk ) The sign is true if and only if the initial epochs of B and A are the same, further denoted as t _Bnk -t _ABnk ＝(T _k -Δt _s ). Then, by shifting the time axis at the time of the coordinate of b, the shift amount is (T _k -Δt _s ) Delay deltat of pulse sequence number information can be eliminated _s The effect of (a) is to make the initial epoch of b and a identical, i.e. t _Bnk ＝t _Ank +T _k . Due to pulse period T _k >(t _dA +t _ds ) It can be seen that the observed events are the same pulse event in the whole period space-time span range of the space-time keeping subsystem A and the observer B, and the space-time keeping subsystems A and B acquire the same initial epoch. The initial epoch transfer process is performed sequentially from large to small in period.

In the embodiment of the application, the pulse sequence number information broadcast and received by the space time keeping subsystem forms a database; time axis for judging whether pulse event is abnormal and translating coordinatesInteger multiple period T _x Eliminating abnormality; adjusting the orbit parameter calendar to further converge to the pulse event deviation less than + -0.5T _x 。

The space time keeping subsystem broadcasts pulse sequence number information, which is the obligation of the space time keeping subsystem, and in order to make the whole space time keeping system stable, the time user system obtains time unified information, and the space time keeping subsystem must broadcast the pulse event which is independently measured.

The whole space always has pulse sequence number information broadcast by a plurality of space time keeping subsystems, and the pulse sequence number information can be used by a time user system and can also be used by the space time keeping subsystems to implement feedback adjustment.

The pulse sequence number information broadcast and received by the space-time keeping subsystem forms a first database. At least three space time keeping subsystems are configured, each of which independently measures a plurality of pulsars and calculates the moment when the pulse of each serial number of each pulsar reaches a wide point, namely, the pulse event (serial number-time), and broadcasts pulse serial number information to observers.

The observers receive the pulse sequence number information broadcast by the space time keeping subsystem to form a data table which is classified by the pulse star and takes the pulse sequence number as an index, namely a sequence number table for short, and the data table which is different from the data table classified by the space time keeping subsystem can be also called a first data table. As shown in fig. 5, the leftmost column of the first data table is the pulse sequence number and the different columns of the same row are the times of the pulse events from the various spatial time keeping subsystems. The first data table is not necessarily filled up due to transmission obstacles, allowing a part of the cells of the first data table to be empty.

And secondly, judging whether the pulse event is abnormal or not, and eliminating the abnormality of the initial epoch of the time axis when the coordinates are translated. The same pulse event (sequence number-time) should be measured the same for different observers as required by the initial epoch and pulsar sequence number rules, i.e. the same row of pulse sequence number in the table of the first data table shown in fig. 5 and the measured times of different space-time subsystems should be the same. However, each spatial daemon subsystem measurement is subject to error and can only be kept consistent within a certain allowable deviation, also referred to as a consistency criterion. When the space conservation subsystem exceeds a predetermined range, the pulse event abnormality of the space conservation subsystem is indicated, and the space conservation subsystem needs to adjust the pulse event.

The relation between the space time keeping subsystems is a balance, each space time keeping subsystem checks the difference between the time in the pulse event (sequence number-time) and the average value of other space time keeping subsystems, if the difference exceeds one whole period, the initial epoch of the time axis when the coordinates need to be translated, the time coordinate axis is translated, and the integer times of the period is increased or decreased.

FIG. 6 is a diagram showing the data classified by pulsar according to the embodiment of the present application, wherein in the table of the data classified by pulsar, the observer checks whether the pulse event of the pulsar with long period is abnormal or not, and checks the pulsar with smaller period again, so that the difference between the time and the average value of the observer under the same serial number within a certain allowable deviation range is smaller than one period T _x The requirement of the magnitude. To distinguish the data table shown in fig. 5, the data table classified by pulsar may also be referred to as a second data table.

The average value is the average value of time in the same pulse event of other space time keeping subsystems except the local observer, the time difference value of the space time keeping subsystems participating in the average value calculation on the same pulse event is not larger than the period of the pulse star, if the respective phase difference is large, the average value cannot be selected, a few obeying majority rules are adopted, the space time keeping subsystem with the largest deviation is removed, then the time average value is calculated, and the initial epoch of the time axis in coordinate translation is translated by the redetermined time average value; or with reference to time in a pulse event observed on earth.

Finally, the local orbit parameter calendar table is adjusted to further converge to the time deviation of less than +/-0.5T in the pulse event _x . If long-term adjustment is performed, the long-term means that at least one revolution orbit period is required, each space time keeping subsystem can ensure that the time in the same serial number row is consistent within a certain allowable deviation range in the table row of the first data table corresponding to each pulse serial number of each pulsar, thereby meeting the consistency requirement and deviationAnd the space conservation subsystem with larger difference can reduce the deviation by adjusting the local orbit parameter calendar.

The local track parameter calendar plays a role in regulation in two calculation processes, namely, calculating the delay time from the local to the wide point by using the track position parameters, and giving a pulse event a wide point time; and secondly, in the pulse profile measurement process, local orbit parameters are needed to be used when the pulse profile is converted to coordinates from original positions.

In this embodiment of the present application, a set stability bias algorithm of a pulsar database is also described, which specifically includes: each space conservation subsystem maintains the same pulsar database. The pulsar database is a collection of pulsar ephemeris including, but not limited to, the following information: pulsar name, orientation vector of pulsar, pulsar pulse profile, initial phase of pulsar profile, zero-phase model of pulsar profile, pulsar pulse period, correction value of pulsar pulse period and correction value of initial phase.

Each space time keeping subsystem checks its own pulse sequence number information database, and a data table classified by the space time keeping subsystem and indexed by the coordinate time, referred to as a time table for short, is shown in fig. 6, wherein the leftmost column of the second data table is the coordinate time of the local viewer, and the different columns of the same row are integer sequence numbers of different pulsars at the moment. And taking the serial number of the same row as the input of the set stability criterion inequality (4), and calculating the matrix difference at the left side of the inequality to obtain the set stability deviation.

The embodiment of the application provides a set stability deviation algorithm of a pulsar database, which does not relate to how to agree on the pulsar database and propagation thereof.

In the embodiment of the application, a time user system is also described, wherein the time user system is a unified time-consuming system for realizing coordinates by utilizing a pulsar sequence number rule, receiving the pulsar sequence number information broadcast by other space time-keeping subsystems, measuring the pulse signals of the pulsar in time and observing the pulsar, calculating and translating the initial epoch of a time axis when the coordinates are self and adjusting a local orbit parameter calendar. Fig. 7 is a schematic diagram of a composition structure of a time user system provided in an embodiment of the present application, and as shown in fig. 7, the time user system in an embodiment of the present application includes: the system comprises an original measuring device, a pulsar measuring device, a device for receiving broadcast information, a local track parameter calendar, a pulse sequence number information database, a pulse sequence number rule and the like. The solid line box in fig. 7 is a time user system component, and the dashed line box is a variable in the time coordinate axis transformation process.

In this embodiment of the present application, the time user system has the same hardware and software configuration as the space time keeping subsystem except that the time user system cannot broadcast the pulse sequence number information.

The original measuring device is a reference device for locally reproducing SI seconds, is currently defined by a cesium atomic clock, and adopts a related device recommended by international units if new SI definitions exist in the future. The time measurement device provides an equidistant sampling clock for the pulsar measurement device, establishes a local time coordinate axis and an calendar rule reflecting periodic movement based on the time coordinate axis, outputs local standard time and provides time service signals for the local area of the time user system to realize the local time unification of the time user system.

Further, the original coordinate axis can be related to the coordinate axis when the coordinate is transformed by the following formula (5), and the corresponding relation of the scale marks on the two coordinate axes can be determined as long as the initial epoch when the coordinate is known.

In formula (5): Δt is the time interval of the time axis when coordinates are given; τ is the time variable of the local origin; u is the local power potential, V is the linear velocity relative to the wide point, and c is the speed of light.

The pulsar measuring device is a measuring device for receiving pulsar signals and outputting pulse arrival time, the pulsar signals are driven and sampled by a local time-consuming clock, received pulsar photon signals are converted into pulse profiles, the position, speed and power potential information of a local orbit parameter calendar are combined, doppler time axis transformation, relativity time axis transformation and projection distance time-space delay are carried out, the time when the current pulse sequence number reaches a wide point is finally obtained, the current pulse sequence number is marked on a coordinate axis when the coordinates are obtained, a pulse event is formed, and the pulse event is reported to a pulse sequence number information database. The transformation algorithm is described in the related Chinese patent application with publication number of CN111665709A and the name of a method for unifying time in wide area space and a space time keeping subsystem.

The broadcast information receiving device is a device capable of receiving pulse sequence number information sent by other space time keeping subsystems, and the pulse sequence number information from different subsystems is directly stored in a pulse sequence number information database.

The local track parameter calendar is a data table corresponding to time and space, and when the time index is local, the data record is a position vector, a speed vector and a power potential. If the time index on earth is an international atomic time (InternationalAtomic Time, TAI), the time index outside earth is not the centroid-dynamics time (BarycenterDynamics Time, TDB) defined by the international union, but the time measured by the time user system's own in-situ measurement device.

The pulse sequence number information database is a database stored in a time user system, collects the pulse sequence number information broadcast by each subsystem in space conservation and pulse event information generated by locally observing pulse stars, and if the database information is discontinuous or blank is left, the blank of the database is complemented by a prediction algorithm.

The pulse sequence number rule is an algorithm and a criterion for processing a pulse sequence number information database to determine whether data are reasonable, when the fact that a locally observed pulse event exceeds a criterion allowable deviation is found, the time axis translation adjustment of a user system coordinate can be realized through translating an initial epoch of the time axis when the coordinate is translated in the time user system, the translation magnitude is integral multiple of a pulse star period, and a local orbit parameter calendar can also be adjusted to enable the pulse event time of the time user system to be consistent with most of other subsystems within the magnitude of one pulse star period. Thereby achieving the purpose of unifying time.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present invention, the sequence numbers of the foregoing processes do not mean the order of execution, and the order of execution of the processes should be determined by the functions and internal logic thereof, and should not constitute any limitation on the implementation process of the embodiments of the present application. The foregoing embodiment numbers of the present application are merely for describing, and do not represent advantages or disadvantages of the embodiments.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above described device embodiments are only illustrative, e.g. the division of the units is only one logical function division, and there may be other divisions in practice, such as: multiple units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. In addition, the various components shown or discussed may be coupled or directly coupled or communicatively coupled to each other via some interface, whether indirectly coupled or communicatively coupled to devices or units, whether electrically, mechanically, or otherwise.

The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units; can be located in one place or distributed to a plurality of network units; some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated in one processing unit, or each unit may be separately used as one unit, or two or more units may be integrated in one unit; the integrated units may be implemented in hardware or in hardware plus software functional units.

The foregoing is merely an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present invention, and the changes and substitutions are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of unifying time based on pulsar sequence number rules, the method comprising:

In the inertial reference system, a wide-area inertial coordinate system is created, and the mass center of all the masses in the gravitational potential range or the whole range is set as a coordinate origin, which is called a wide point; wherein, the observers in the wide area inertial coordinate system at least comprise a space time keeping subsystem and a time user system; the wide point is a spatial reference point of all observers, the attraction at the wide point is zero, and the observer speed at the wide point is zero; the viewer at the broad point is a broad point viewer; for all observers, the pulsar pulse signal and corresponding pulsar received by the wide-point observer has the following stable characteristics: pulsar azimuth, pulse period, and pulse profile, including: the pulsar azimuth is azimuth acceptance or appointed azimuth; the pulse period is a period acceptance or agreement period; the pulse profile is a pulse profile acceptance or contract profile; wherein the azimuth of a pulsar refers to an angular coordinate vector in the wide area inertial coordinate system, and is agreed by all observers; obtaining the projection distance of the observer on the certain pulsar azimuth by the dot product of the unit vector of the angular coordinate vector and the coordinate of the observer; the pulse signal passes through or reaches a viewer in the form of plane electromagnetic wave in the direction pointing to a certain pulsar from the wide point, and also passes through or reaches the wide point, and the projection distance between the viewer and the wide point in the direction accords with a two-dimensional space-time relationship with the time difference when the plane electromagnetic wave of the same pulse signal passes through the coordinates of the viewer and the wide point successively, namely delta t=d/c, wherein delta t is the time difference expressed when the coordinates is expressed in terms of SI seconds; d is the projection distance of the observer in the direction of the pulsar, and the unit is SI meters; c is the speed of light;

according to the pulse sequence number information, implementing a feedback adjustment mechanism of the space time keeping subsystem;

the pulse period of the pulsar has set stability, wherein the set stability criterion of the pulse period comprises:

the set of stability criteria includes: maximum allowable deviation epsilon is respectively set for 2-k pulsars ₂ 、ε ₃ 、...、ε _k Forming a criterion array on the right side of the inequality sign in the inequality (4), wherein NC represents no criterion; if one element in the criterion array in the inequality (4) does not meet the inequality condition, adjusting the period of the pulsar corresponding to the element which does not meet the condition or removing the period from the set of the pulsar;

the pulse profile is a pulse profile acceptance or contract profile comprising:

2. The method of claim 1, wherein the process of delivering the pulsar initial epoch includes broadcasting and receiving pulse sequence number information;

pulsar name k, pulse sequence number n ^(k) The time of the pulse reaching the wide point is the pulse origin time t _nk Space-time keeping subsystem x as broadcaster, when the space-time keeping subsystem x receives pulse sequence number n ^(k) Projection distance d from time x to broad point _xk Delay time t of signal processed by space time keeping subsystem x _dx ；

The initial epoch of the pulsar is all pulsars which are identified or agreed by the space time keeping subsystem, the time when the pulse with the sequence number of zero reaches a wide point is zero, the value at the coordinate is zero, and the initial phase is the difference between the starting point of the pulse profile and the origin of the time axis; for a viewer newly joining in the space time keeping system, a transfer or inheritance process is needed to obtain the agreed initial epoch of the pulse star at one time, so that the time axis origin or time zero point in the initial epoch in the coordinate is unified with other space time keeping subsystems; wherein, the observer newly joining the space conservation subsystem comprises a new space conservation subsystem or a time user system;

the time difference of adjacent integer serial numbers of the pulse is a pulse period interval; in the space-time range of one pulse period interval, the observer b receives the pulse sequence number information sent by the space time keeping subsystem a, if the sum of the information processing delay and the space transmission delay is deltat _s Less than pulse period T _k T, i.e _k >Δt _s The observer b receives the pulse sequence number information and then generates a slave pulseDelay time deltat is calculated from the observed result of the flushing event _s And translating a time axis when coordinates are translated, so as to realize the transmission of an initial epoch from the space time keeping subsystem a to the observer b, specifically, the pulse event refers to the time when a pulse signal of a pulsar reaches the wide point and a corresponding serial number, and the time is expressed as follows: events (sequence number, time); the viewer b inherits the pulse event (n) from the pulse sequence number information of the space-time keeping subsystem a ^(k) ,t _ank ) The inheritance means that the observer b designates the event sequence number of the pulsar named k as n ^(k) The corresponding time is assigned t _abnk Then, the observer b observes for a while, and the observer b measures the next pulse event (n ^(k) +1,t _bnk ) The method comprises the steps of carrying out a first treatment on the surface of the Within a pulse period space-time range, should T _k ≥(t _bnk -t _abnk ) The equal sign holds if and only if the initial epoch of observer b and space conservation subsystem a are the same, due to Δt _s ＝t _abnk -t _ank Then t _bnk -t _abnk ＝(T _k -Δt _s ) The method comprises the steps of carrying out a first treatment on the surface of the By shifting the time axis at the time of the coordinates of viewer b, the delay deltat of the pulse sequence number information is eliminated _s The influence of (a) is such that the initial epoch of viewer b and space-time keeping subsystem a is the same, i.e. t _bnk ＝t _ank +T _k ；

alternatively, the inheriting the initial epoch agreed by the existing space conservation subsystem includes: in particular by translational sittingThe time-scale coordinate axis mode is realized: within a periodic spatiotemporal span, the same pulse signal of the same pulsar observed by the space daemon a and the observer b reaches the broad point, the pulse event (n ^(k) 、t _nk ) The method is unique, and the process of inheriting the initial epoch is only carried out once, so that the consistent and agreed initial epoch can be obtained; the events referenced by the space conservation subsystem a and the observer b are not limited to pulse events, but also comprise known events agreed by the two parties, and the known events comprise bidirectional electromagnetic wave signals.

3. The method of claim 2, wherein implementing a feedback adjustment mechanism for a space-time keeping subsystem based on the pulse sequence number information comprises:

4. A method according to claim 3, wherein the viewer determines whether the impulse event is abnormal, and in the event of the impulse event abnormality, adjusting the initial epoch elimination abnormality of the coordinate axis at the time of the coordinate by shifting the time axis at the time of the coordinate comprises:

According to the consistency requirement of the initial epoch and the sequence number rule of the pulsar, the time measured by the same pulsar event for different observers is the same, and the time measured by the same row of pulse sequence numbers in the first data table and different space time keeping subsystems is the same theoretically, which is called a consistency criterion;

each observer checks the difference between the time in the pulse event and the time average value in the pulse event of other space daemon subsystems, and if the difference exceeds one pulse period, the initial epoch is adjusted, and the time axis when the coordinates are shifted is adjusted, so that the time in the pulse event of the observer is consistent with the average value; the time difference of the space time keeping subsystem participating in the average value calculation on the same pulse event is smaller than or equal to the period of the pulsar corresponding to the pulse; if the time difference value of the space time keeping subsystem participating in the average value calculation on the same pulse event is larger than the value of the period of the pulsar corresponding to the pulsar or larger than a set threshold value, adopting a few obeying majority rules, calculating a time average value after eliminating the space time keeping subsystem with the largest deviation, and adjusting the initial epoch of a time coordinate axis by the redetermined time average value; or taking time in a pulse event observed on earth as a reference;

In the first data table, the observer checks whether the pulse event of the long-period pulsar is abnormal or not preferentially, and then checks the pulse event of the short-period pulsar, so that the difference between the time and the time average value of the observer under the same sequence number within a certain allowable deviation range is smaller than one pulse period T _x I.e. meeting a consistency criterion.

5. The method of claim 3, wherein the adjusting the observer's track parameter calendar causes the time deviation of the pulse event to converge to less than + -0.5T _x Comprising:

if at least one revolution orbit period is subjected to feedback adjustment, each space time keeping subsystem can ensure that the time of the same sequence number row in a table row corresponding to the pulse sequence number of each pulsar in the first data table meets a consistency criterion within a certain allowable deviation range; for the space timekeeping subsystem exceeding the allowable deviation, adjusting the local track parameter calendar to reduce the time deviation;

6. The method according to claim 1 or 4, characterized in that the method further comprises:

7. A time user system according to any one of claims 1 to 6, wherein the system comprises: the system comprises an in-situ measurement device, a pulsar measurement device, a device for receiving broadcast information, a local track parameter calendar, a pulse sequence number information database and a pulse sequence number rule; the pulse sequence number rule is an algorithm and a criterion for processing a pulse sequence number information database to determine whether data are reasonable, when the fact that a locally observed pulse event exceeds a criterion allowable deviation is found, the time axis translation adjustment of the time axis when the coordinates of the time user system are realized through the initial epoch of the time axis when the coordinates are translated in the time user system, the translation magnitude is an integer multiple of a pulse star period, or a local orbit parameter calendar is adjusted, so that the pulse event time of the time user system is within the magnitude of one pulse star period and is consistent with most of other subsystems;

the time-of-day measuring device is used for obtaining local time-of-day;

8. The system of claim 7, wherein the time user system has the same hardware-software configuration as the space-time subsystem except that it is unable to broadcast pulse sequence number information;