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CN106908817B - Assisting navigation localization method and system - Google Patents

Assisting navigation localization method and system Download PDF

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Publication number
CN106908817B
CN106908817B CN201710082667.4A CN201710082667A CN106908817B CN 106908817 B CN106908817 B CN 106908817B CN 201710082667 A CN201710082667 A CN 201710082667A CN 106908817 B CN106908817 B CN 106908817B
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gnss
gnss signal
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signal
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CN106908817A (en
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丁元
张光华
肖鹏
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Shenzhen Si Kai Microtronics AS
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Shenzhen Si Kai Microtronics AS
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42—Determining position
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H2201/00—Aspects of broadcast communication
    • H04H2201/10—Aspects of broadcast communication characterised by the type of broadcast system
    • H04H2201/18—Aspects of broadcast communication characterised by the type of broadcast system in band on channel [IBOC]
    • H04H2201/183—FM digital or hybrid

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

The invention discloses a kind of assisting navigation localization method and systems.The described method includes: receiver receives current GNSS signal, it is less than predetermined power in the power of the current GNSS signal, and when the carrier-to-noise ratio of the current GNSS signal is less than default carrier-to-noise ratio, obtain the GNSS auxiliary information sent by GNSS auxiliary reference station by CDRadio channel, it is completed according to the GNSS auxiliary information the capture of current GNSS signal, tracking and calculates pseudorange difference with the position vector of the determination receiver, and the location information of the receiver is determined according to the position vector, to realize that assisting navigation positions.The GNSS signal auxiliary information that the present invention is sent by CDRadio channel come realize assisting navigation position, mobile Internet is solved to transmit the instability problem of GNSS signal auxiliary information, has been obviously improved the practical ranges and user experience of highly sensitive GNSS receiver.

Description

Auxiliary navigation positioning method and system
Technical Field
The invention relates to the field of communication, in particular to an auxiliary navigation positioning method and an auxiliary navigation positioning system.
Background
After the 21 st century, the satellite navigation technology has achieved great success in the market, and with the wide application of the satellite navigation technology, people have higher and higher requirements on the satellite navigation technology, for example, people want to obtain their own position in real time in mountainous areas where people pass through dense vegetation or indoors; however, in general, in mountainous areas with dense vegetation or indoors, GNSS signals are weak, and when satellite signals are very weak, the conventional receiver cannot capture the satellite signals due to extremely low signal-to-noise ratio; under the condition of weak GNSS signals, a high-sensitivity GNSS receiver often needs to adopt an accumulation method to improve the signal-to-noise ratio of the captured and tracked GNSS signals, and the capturing and tracking of the GNSS signals can be completed only when the signal-to-noise ratio of the GNSS signals exceeds a certain threshold. The high-sensitivity GNSS receiver can perform positioning by solving a coarse navigation equation after acquiring at least five GNSS satellite signals, but if such a coarse navigation equation is directly solved, the problem of turning of an integer number of milliseconds exists. At present, the most common solution to the whole millisecond digital ambiguity problem is to provide a high-sensitivity GNSS receiver with position coordinates of an auxiliary reference station, satellite ephemeris and reference time, and the receiver can eliminate the whole millisecond rollover problem according to the prior information, so as to obtain the whole pseudorange of the corresponding satellite, and then obtain the positioning result of the receiver by solving the reconstructed coarse time navigation equation.
In the prior art, a mainstream transmission scheme of GNSS signal assistance information is completed by using a mobile internet, and due to the complex topological structure of the internet and the inherent characteristics of small coverage, large delay dynamic range, cell switching, multi-user concurrency and the like of mobile communication, the GNSS assistance information transmission is often unstable, and the practical application and user experience of a high-sensitivity GNSS receiver are greatly influenced.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The invention mainly aims to provide an auxiliary navigation positioning method and an auxiliary navigation positioning system based on CDCDRAdio, and aims to solve the technical problem that GNSS signal auxiliary information transmission in the prior art is unstable.
In order to achieve the above object, the present invention provides an assisted navigation positioning method, including:
the method comprises the steps that a receiver receives a current GNSS signal, and when the power of the current GNSS signal is smaller than a preset power and the carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio, GNSS auxiliary information sent by a GNSS auxiliary reference station through a CDRAdio channel is obtained;
extracting the star number of the current visible satellite, the carrier Doppler frequency of the satellite observed by the GNSS auxiliary reference station, the satellite ephemeris, the position information of the GNSS auxiliary reference station and the reference time from the GNSS auxiliary information;
when the carrier Doppler frequency, the phase of the current GNSS signal spread spectrum code and the current visible star meet preset conditions, capturing the current GNSS signal, tracking the current GNSS signal in the reference time, and taking the current GNSS signal in the reference time as a target GNSS signal;
determining a priori estimated pseudorange of the target GNSS signal according to the position information of the GNSS auxiliary reference station;
calculating expected fraction pseudo-ranges of all satellites according to the satellite ephemeris, the position information of the GNSS auxiliary reference station and reference time, selecting one satellite as a reference satellite, and generating full pseudo-ranges according to the expected fraction pseudo-ranges of the reference satellite and the expected fraction pseudo-ranges of other satellites;
calculating a pseudo-range difference value between the prior estimated pseudo-range and the full pseudo-range, determining a position vector of the receiver according to the pseudo-range difference value, and determining position information of the receiver according to the position vector of the receiver so as to realize auxiliary navigation positioning.
Preferably, after the GNSS assistance information transmitted by the GNSS assistance reference station through the cdladio channel is acquired, the method further includes:
and verifying the current GNSS signal, and if the current GNSS signal passes the verification, determining the current GNSS signal to be the required current GNSS signal.
Preferably, the verifying the assisted current GNSS signal specifically includes:
demodulating and stripping the carrier Doppler frequency of the current GNSS signal according to the GNSS auxiliary information, performing coherent and noncoherent accumulation on the demodulated and stripped GNSS signal, then correlating the GNSS signal with a local recurrence code, comparing the correlated result with a preset threshold value, and when the correlated result is greater than or equal to the preset threshold value, passing verification and confirming that the current GNSS signal is the required current GNSS signal.
Preferably, after comparing the correlated result with a preset threshold, the method further includes:
and when the correlated result is smaller than the preset threshold value, the verification is failed, and the current GNSS signal is received again.
Preferably, after said computing pseudorange differences between said a priori estimated pseudoranges and said full pseudoranges, said method further comprises:
judging whether the pseudo-range difference value is smaller than a preset difference value or not, and determining whether the pseudo-range difference value is a required pseudo-range difference value or not;
when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value;
and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
In order to achieve the above object, the present invention further provides an assisted navigation positioning system, including: the signal receiving module is used for receiving a current GNSS signal, and acquiring GNSS auxiliary information sent by a GNSS auxiliary reference station through a CDRAdio channel when the power of the current GNSS signal is smaller than a preset power and the carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio;
the auxiliary information extraction module is used for extracting the current visible star number, the carrier Doppler frequency of the satellite observed by the GNSS auxiliary reference station, the satellite ephemeris, the position information of the GNSS auxiliary reference station and the reference time from the GNSS auxiliary information;
a target signal confirmation module, configured to capture the current GNSS signal and track the current GNSS signal within the reference time when the carrier doppler frequency, the phase of the current GNSS signal spreading code, and the current visible star number satisfy preset conditions, and use the current GNSS signal within the reference time as a target GNSS signal;
a priori estimated pseudo-range determining module, configured to determine a priori estimated pseudo-range of the target GNSS signal according to the location information of the GNSS assisted reference station;
the full pseudo-range generation module is used for calculating the expected fraction pseudo-range of each satellite according to the satellite ephemeris, the position information of the GNSS auxiliary reference station and reference time, selecting one satellite as a reference satellite, and generating a full pseudo-range according to the expected fraction pseudo-range of the reference satellite and the expected fraction pseudo-range of other satellites;
and the position determining module is used for calculating a pseudo-range difference value between the prior estimated pseudo-range and the full pseudo-range, determining a position vector of the receiver according to the pseudo-range difference value, and determining position information of the receiver according to the position vector of the receiver so as to realize auxiliary navigation positioning.
Preferably, the system further comprises:
and the signal verification module is used for verifying the current GNSS signal, and if the current GNSS signal passes the verification, the current GNSS signal is confirmed to be the required current GNSS signal.
Correspondingly, the signal verification module is further configured to demodulate and strip the carrier doppler frequency of the current GNSS signal according to the GNSS assistance information, correlate the demodulated and stripped GNSS signal with a local recurrence code after coherent and non-coherent accumulation, compare a result after correlation with a preset threshold value, and when the result after correlation is greater than or equal to the preset threshold value, verify that the current GNSS signal is the required current GNSS signal.
Correspondingly, the signal verification module is further configured to, when the correlated result is smaller than the preset threshold value, fail the verification and re-receive the current GNSS signal.
Correspondingly, the position determining module is further configured to determine whether the pseudorange difference is smaller than a preset difference, and determine whether the pseudorange difference is a required pseudorange difference;
when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value;
and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
According to the invention, the auxiliary navigation and positioning are realized through the GNSS signal auxiliary information sent by the CDRAdio channel, the problem of instability of the mobile internet for transmitting the GNSS signal auxiliary information is solved, and the actual application range and the user experience of the high-sensitivity GNSS receiver are remarkably improved.
Drawings
FIG. 1 is a flow chart of an aided navigation positioning method according to the present invention;
FIG. 2 is a schematic flow chart illustrating GNSS aiding information verification in an aided navigation positioning method according to the present invention;
FIG. 3 is a schematic diagram illustrating a pseudo-range difference validation process in an aided navigation positioning method according to the present invention;
FIG. 4 is a schematic flow chart illustrating a procedure of generating a full pseudorange in an aided navigation positioning method according to the present invention;
FIG. 5 is a schematic view of a scene flow for implementing an assisted navigation positioning method according to the present invention;
FIG. 6 is a functional block diagram of a first embodiment of an aided navigation positioning system according to the present invention;
FIG. 7 is a functional block diagram of an aided navigation positioning system according to a second embodiment of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Fig. 1 is a flow chart of an assisted navigation positioning method according to the present invention, and referring to fig. 1, the method includes:
s1, the receiver receives a current GNSS signal, and when the power of the current GNSS signal is smaller than a preset power and the carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio, GNSS auxiliary information sent by a GNSS auxiliary reference station through a CDRAdio channel is obtained;
it should be noted that the fact that the power of the GNSS signal is less than the preset power and the carrier-to-noise ratio is less than the preset carrier-to-noise ratio means that under the condition of weak GNSS signal, generally, the received power is < -150dBm, and under the condition that C/N0 is less than 25dB · Hz, at this time, the ordinary satellite navigation receiver cannot work in these environments, so a high-sensitivity GNSS receiver is generally used, but the high-sensitivity GNSS receiver often needs to adopt an accumulation method to improve the signal-to-noise ratio of the captured and tracked GNSS signal, and the capturing and tracking of the GNSS signal can be completed only when the signal-to-noise ratio of the GNSS signal exceeds a certain threshold;
it is understood that the GNSS assistance information includes: the GNSS auxiliary station reference time, the GNSS auxiliary station position coordinates, the current visible star, the telegraph text of the corresponding satellite, the Doppler frequency of the satellite observed by the GNSS auxiliary station, the satellite ephemeris and the like; it should be understood that the GNSS is generally referred to as Global navigation satellite System (Global navigation satellite System), which refers to all satellite navigation systems, including Global, regional, and enhanced, such as the GPS in the united states, the Glonass in russia, Galileo in europe, the beidou satellite navigation System in china, and also covers other satellite navigation systems under construction and later to be constructed.
It can be understood that the cdrio is short for chinese Digital audio (China Digital Radio). The digital frequency modulation radio frequency identification device is specially designed for China frequency modulation broadcasting, can more effectively utilize the spectrum gap between the frequency bands of the existing analog frequency modulation by using key technologies such as irregular spectrum allocation, OFDM modulation, LDPC error correction coding, time slicing, layered modulation and the like, has the characteristics of high receiving sensitivity, strong anti-interference capability and the like, simultaneously enables digital signals and analog signals to coexist in the same frequency band, and is an advanced technology which is originally created globally;
s2, extracting the star number of the current visible satellite, the carrier Doppler frequency of the satellite observed by the GNSS auxiliary reference station, the satellite ephemeris, the position information of the GNSS auxiliary reference station and the reference time from the GNSS auxiliary information; understandably, the auxiliary information comprises the auxiliary reference station time, the prior position of the auxiliary station, the satellite ephemeris and information of the current visible satellite number, text, Doppler frequency and the like which can assist navigation positioning;
s3, when the carrier Doppler frequency, the phase of the current GNSS signal spread spectrum code and the current visible star meet preset conditions, capturing the current GNSS signal, tracking the current GNSS signal in the reference time, and taking the current GNSS signal in the reference time as a target GNSS signal;
it should be noted that the capturing process is a process of sending the carrier doppler frequency and the telegraph text information of the current GNSS signal to the receiver through the cdraadio channel within the auxiliary reference time, and compared with a mode of sending through a mobile communication network in the prior art, the carrier doppler frequency and the telegraph text information of the GNSS signal can be timely, accurately and stably obtained by sending through the cdraadio channel according to the present invention, and the accumulation time for coherent accumulation and noncoherent accumulation can be shortened, so that the signal-to-noise ratio of the GNSS signal can be more rapidly improved;
it is understood that the GNSS navigation signals can be represented as:
where √ 2P is the signal amplitude, D (t) is the spreading code of the current GNSS signal, C (t) is the pseudo-random noise code (PN), cos (2 π f)IFt + θ) is a carrier signal.
As can be seen from the above formula, the complete GNSS signal mainly comprises three parts, namely, the phase D (t) of the spreading code of the current GNSS signal, the PN code C (t), and the carrier cos (2 π f)IFt + θ). The carrier part of the GNSS signal can be demodulated through a carrier generated locally by a receiver, the GNSS signal after the carrier is stripped is correlated with a PN code reproduced locally, the correlated result is compared with a threshold, if the correlated result exceeds the threshold, the acquisition is considered to be successful, otherwise, the acquisition is failed; in the GNSS acquisition process, two-dimensional correlation and search are performed on a target GNSS signal in two dimensions of frequency and PN code phase, when the maximum value of a two-dimensional correlation result passes a preset threshold, acquisition is successful, and the frequency and code phase corresponding to the maximum value are initial values of carrier doppler frequency and PN code phase of the acquired GNSS signal;
in a specific implementation, when the GNSS signal is a weak signal, a maximum value obtained by one two-dimensional search often cannot pass a threshold, and the signal-to-noise ratio of the GNSS signal is often improved by a coherent and non-coherent accumulation method for a period of time. However, if the carrier-doppler frequency of the GNSS signals over the accumulation period is unknown, the receiver either takes a long time to guess and try-and-error to determine the carrier-doppler frequency of the captured GNSS signals or estimates the carrier-doppler frequency by employing a very complex signal processing model, whichever scheme does not provide the user with a satisfactory customer experience. Therefore, when weak GNSS signals are captured, the carrier Doppler frequency and the telegraph text information of the GNSS signals in the auxiliary reference time are sent to the receiver through the CDRAdio channel, and the problems can be well solved.
It should be understood that, after the GNSS signal is successfully captured, the GNSS signal which is successfully captured is tracked, multiplied by two paths of orthogonal carriers which are locally generated to complete the demodulation operation of the carrier, then respectively integrated with the instantaneous code generated by the local PN code generator, the advanced code of the advanced half chip and the lagging code of the lagging half chip, and the integrated result is transmitted to the carrier tracking loop and the code tracking loop for tracking, and the obtained tracking result is fed back to the local carrier and the local code generator for adjustment;
in a specific implementation, when the GNSS signal is a weak signal, the signal-to-noise ratio of the result of one integration is often very poor, which results in that the tracking cannot be locked or the tracking loop is out of lock, and then it is necessary to increase the input signal-to-noise ratio of the tracking loop by coherent and non-coherent accumulation methods for a period of time. However, if the navigation message of the GNSS signal is unknown during the accumulation period, it takes a long time to guess and try to make a mistake to determine the navigation message of the tracked GNSS signal, and such a method does not provide a satisfactory user experience to the user. Therefore, compared with the mobile communication transmission in the prior art, when weak GNSS signals are tracked, the auxiliary information can be timely, accurately and stably provided for the GNSS receiver through the CDRAdio channel, and the problem is solved.
S4, determining a priori estimated pseudo range of the target GNSS signal according to the position information of the GNSS auxiliary reference station;
it should be noted that the a priori estimated pseudorange is a pseudorange that estimates a priori state of the auxiliary reference station through the position information of the auxiliary reference station;
it is understood that the pseudorange is a signal that the GNSS satellite can transmit a pseudo-random noise code according to the satellite-borne clock, which is called a ranging code signal (i.e. a coarse code C/a code or a fine code P code); the signal is transmitted from the satellite over a time Δ t to the receiver antenna; multiplying the propagation time Δ t of the signal by the speed c of the electromagnetic wave in vacuum to obtain the geometrical space distance ρ from the satellite to the receiver, i.e., ρ ═ Δ tc; in fact, since the propagation time Δ t includes an error of the satellite clock not being synchronized with the receiver clock, a satellite ephemeris error, a receiver measurement noise, a delay error of the ranging code propagating in the atmosphere, and the like, the distance value obtained thereby is not a true satellite-to-satellite geometric distance, and is conventionally called a "pseudorange";
s5, calculating expected fraction pseudo ranges of all satellites according to the satellite ephemeris, the position information of the GNSS auxiliary reference station and reference time, selecting one satellite as a reference satellite, and generating full pseudo ranges according to the expected fraction pseudo ranges of the reference satellite and the other satellites;
s6, calculating a pseudo range difference value between the prior estimation pseudo range and the full pseudo range, determining a position vector of the receiver according to the pseudo range difference value, and determining position information of the receiver according to the position vector of the receiver to realize auxiliary navigation positioning.
In a specific implementation, the determining the position vector of the receiver according to the pseudorange difference generally substitutes the position vector into a coarse navigation equation to obtain the position vector;
it can be understood that a high-sensitivity GNSS receiver can perform positioning by solving the coarse navigation equation after acquiring at least five GNSS satellite signals, but if such coarse navigation equation is directly solved, the problem of turning by an integer millisecond exists. The most common solution to the whole millisecond digital analog ambiguity problem at present is to provide a high-sensitivity GNSS receiver with position coordinates of an auxiliary reference station, satellite ephemeris and reference time, and the receiver can eliminate the whole millisecond number overturning problem according to the prior information, so that the whole pseudorange of the corresponding satellite is obtained, and then the positioning result of the receiver can be obtained by solving the reconstructed coarse time navigation equation;
it should be noted that, in the coarse-time navigation equation, coarse time refers to coarse time, refers to reference time with time accuracy lower than 10ms, a new state variable tc is introduced into the prior state update vector to represent an unknown coarse time error, and then the current state update vector is δ x ═ δx,δy,δz,δb,δtc]T. The new matrix equation can be expressed as:
δz＝Hδx+ε
wherein,in order to be a new observation matrix,is the pseudo range rate, gamma(k)Is the velocity vector of the satellite(s),representing the clock bias rate for satellite number k;
if there are at least 5 independent rows in H, then we can solve for δ x, so it is necessary to obtain pseudorange measurements from at least 5 different satellites. But with the introduction of unknown bias, solving the above five state equations can present a millisecond full cycle ambiguity problem.
In the specific implementation, when people want to acquire their own position in real time in mountainous areas crossing dense vegetation or indoors or when moving at high speed, but the GNSS signal auxiliary information transmission of the auxiliary reference station is completed by using a general mobile internet, because of the complicated topological structure of the internet and the inherent characteristics of small coverage, large delay dynamic range, cell switching, multi-user concurrency and the like of mobile communication, the instability of GNSS auxiliary information transmission is often caused, and the practical application and user experience of the high-sensitivity GNSS receiver are greatly influenced, but the cdladio broadcasting technology in the embodiment can timely, accurately and stably transmit the reference time, position coordinates, currently visible satellite numbers, messages, doppler observation frequencies, ephemeris and other auxiliary information of the GNSS auxiliary reference station to the GNSS receiver, so as to solve the problem of unreliability of the mobile internet for transmitting the signal auxiliary information, the practical application range and the user experience of the high-sensitivity GNSS receiver are remarkably improved.
FIG. 2 is a schematic view illustrating a GNSS aiding information verification process in an aided navigation positioning method according to the present invention; based on the method shown in fig. 1, referring to fig. 2, the method includes:
s11, verifying the current GNSS signal, and if the current GNSS signal passes the verification, confirming that the current GNSS signal is the required current GNSS signal;
it can be understood that, if there is no verification process for the current GNSS signal, the current GNSS signal is not necessarily the best GNSS signal, and if subsequent calculations are performed with such an inaccurate GNSS signal, the result is definitely inaccurate, i.e. the final positioning is not accurate, and may even be very different from the actual position, so that it is necessary to verify the current GNSS signal, so as to screen out the GNSS signal that is better than the requirement, and enable the subsequent positioning to be more accurate.
S12, demodulating and stripping the carrier Doppler frequency of the current GNSS signal according to the GNSS auxiliary information, and correlating the demodulated and stripped GNSS signal with a local recurrence code after coherent and incoherent accumulation;
it should be noted that, the carrier part of the GNSS signal may be demodulated by a carrier generated locally by the receiver, the GNSS signal after the carrier is stripped is correlated with the local replica code, the correlated result is compared with a threshold, if the result exceeds the threshold, the acquisition is considered to be successful, otherwise, the acquisition is failed; in the GNSS acquisition process, two-dimensional correlation and search are performed on a target GNSS signal in two dimensions of frequency and code phase, when the maximum value of a two-dimensional correlation result passes a preset threshold, acquisition is successful, and the frequency and code phase corresponding to the maximum value are initial values of carrier doppler frequency and code phase of the acquired GNSS signal;
s13, judging whether the correlated result is larger than or equal to a preset threshold value;
s14, when the result after correlation is larger than or equal to the preset threshold value, the verification is passed, and the current GNSS signal is confirmed to be the required current GNSS signal; when the correlated result is smaller than the preset threshold value, the verification is not passed, and the current GNSS signal is received again;
in a specific implementation, when the GNSS signal is a weak signal, a maximum value obtained by one two-dimensional search often cannot pass a threshold, and the signal-to-noise ratio of the GNSS signal is often improved by a coherent and non-coherent accumulation method for a period of time. However, if the carrier-doppler frequency of the GNSS signals over the accumulation period is unknown, the receiver either takes a long time to guess and try-and-error to determine the carrier-doppler frequency of the captured GNSS signals or estimates the carrier-doppler frequency by employing a very complex signal processing model, whichever scheme does not provide the user with a satisfactory customer experience. Therefore, when weak GNSS signals are captured, the carrier Doppler frequency and the telegraph text information of the GNSS signals in the auxiliary reference time are sent to the receiver through the CDRAdio channel, and the problems can be well solved.
It should be understood that, after the GNSS signal is successfully captured, the GNSS signal which is successfully captured is tracked, multiplied by two paths of orthogonal carriers which are locally generated to complete the demodulation operation of the carrier, then respectively integrated with the instantaneous code generated by the local PN code generator, the advanced code of the advanced half chip and the lagging code of the lagging half chip, and the integrated result is transmitted to the carrier tracking loop and the code tracking loop for tracking, and the obtained tracking result is fed back to the local carrier and the local code generator for adjustment;
in a specific implementation, when the GNSS signal is a weak signal, the signal-to-noise ratio of the result of one integration is often very poor, which results in that the tracking cannot be locked or the tracking loop is out of lock, and then it is necessary to increase the input signal-to-noise ratio of the tracking loop by coherent and non-coherent accumulation methods for a period of time. However, if the navigation message of the GNSS signal is unknown during the accumulation period, it takes a long time to guess and try to make a mistake to determine the navigation message of the tracked GNSS signal, and such a method does not provide a satisfactory user experience to the user. Therefore, compared with the mobile communication transmission in the prior art, when weak GNSS signals are tracked, the auxiliary information can be timely, accurately and stably provided for the GNSS receiver through the CDRAdio channel, and the problem is solved.
It should be noted that, the weak GNSS signal accumulation method mainly includes coherent accumulation and non-coherent accumulation; due to GNSS message flipping and the presence of unknown doppler frequencies between the receiver and the satellite, the coherence time of the coherent accumulation is very limited (typically not more than 40 ms); although the incoherent accumulation is not affected by the GNSS message inversion, the pure incoherent accumulation under the weak GNSS signal condition has large square loss, so that the efficiency of the incoherent accumulation is low; in practical operation, people often perform coherent accumulation for a period of time before using incoherent accumulation to obtain a good accumulation effect.
It can be understood that, as the cdladio adopts the key technologies of LDPC channel coding, channel estimation equalization, OFDM modulation, etc., a very low bit error rate is still maintained while a lower receiving threshold is ensured, and thus setting the preset threshold value according to the cdladio can relatively increase the number of the captured GNSS signals, and find the GNSS signals meeting the requirements more quickly;
FIG. 3 is a schematic diagram illustrating a pseudo-range difference validation process in an aided navigation positioning method according to the present invention; based on the method shown in fig. 1, referring to fig. 2, the method includes:
s51, calculating a pseudo range difference value between the prior estimation pseudo range and the full pseudo range;
it can be understood that the pseudo-range difference is an adjustable variable, the pseudo-range in the state is predicted according to the estimated prior state, and after the actual pseudo-range measurement is carried out, the estimated state is adjusted according to the deviation between the estimated pseudo-range and the actual pseudo-range;
it should be noted that the a priori estimated pseudorange is a pseudorange that estimates a priori state of the auxiliary reference station through the position information of the auxiliary reference station; the pseudo range is a signal which can be transmitted by a GNSS satellite according to a satellite-borne clock and has a structure of pseudo-random noise code, and is called a ranging code signal (namely a coarse code C/A code or a fine code P code); the signal is transmitted from the satellite over a time Δ t to the receiver antenna; multiplying the propagation time Δ t of the signal by the speed c of the electromagnetic wave in vacuum to obtain the geometrical space distance ρ from the satellite to the receiver, i.e., ρ ═ Δ tc; in fact, since the propagation time Δ t includes an error of the satellite clock not being synchronized with the receiver clock, a satellite ephemeris error, a receiver measurement noise, a delay error of the ranging code propagating in the atmosphere, and the like, the distance value obtained thereby is not a true satellite-to-satellite geometric distance, and is conventionally called a "pseudorange";
s52, judging whether the pseudo-range difference value is smaller than a preset difference value or not, and determining whether the pseudo-range difference value is a required pseudo-range difference value or not;
s53, when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining the position vector of the receiver according to the pseudo-range difference value; when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value; and when the pseudo-range difference is larger than or equal to the preset difference, adjusting the prior position of the auxiliary station or the reference time of the auxiliary station, recalculating the expected fraction pseudo-range, and regenerating the full pseudo-range by combining the fraction pseudo-range of the reference satellite.
It can be understood that, compared with the transmission mode of mobile communication in the prior art, the cdrad channel utilized in the embodiment has the advantages of high receiving sensitivity and strong anti-interference capability, and can quickly, stably and accurately transmit the auxiliary information; the pseudo-range difference obtained according to the auxiliary information is more accurate, the comparison of the pseudo-range difference and the preset difference has an obvious effect, if the positioning result is output when the pseudo-range difference is too large, the positioning result at the moment can not accurately reflect the position of the receiver at the moment, the error can be effectively avoided by comparison, and a certain screening effect is achieved.
FIG. 4 is a schematic flow chart illustrating a procedure of generating a full pseudorange in an aided navigation positioning method according to the present invention; based on the method shown in fig. 1, referring to fig. 4, the method includes:
obtaining the reference time of the auxiliary station, the satellite ephemeris and the prior position of the auxiliary station sent by the CDRAdio, calculating an expected fractional pseudorange, generating a full pseudorange by combining the fractional pseudorange of a reference satellite, comparing the prior estimated pseudorange with the full pseudorange to obtain a pseudorange difference value, solving a coarse navigation equation by using the pseudorange difference value to obtain a position vector, and outputting a positioning result according to the position vector when the pseudorange difference value is smaller than a preset difference value.
It should be noted that, the expected full pseudoranges of all measurement satellites are calculated, and then one satellite is selected as the reference satellite, and in order to distinguish the reference satellite from other satellites, the reference satellite is represented by a superscript (0), and the other satellites are represented by a superscript (k). Assigning an integer value N to a reference satellite(0)Then it reconstructs a full pseudorange of N(0)+Z(0)ms，Z(0)Measured by fingersSub-millisecond pseudoranges, expressed in milliseconds. We can then construct other whole millisecond values with this specified integer.
N(0)The assigned values of (a) contain the common bias in the reconstructed full pseudoranges, which can be expressed by the following equation
Where r is(0)Is the true geometric distance to the satellite,is the geometric distance from the a priori (coarse) transmit instant to the a priori position estimate, d(0)Is thatThe errors present in (a), are caused by a priori position and time errors,is the (known) satellite clock bias, b is the common bias, ε(0)Is the measurement error. All length units are expressed in light milliseconds (the distance light travels in one millisecond time, approaching 300 km).
For satellite k then:
subtracting the two formulas to obtain
From the above equation, it can be seen that the common deviation b is correctly eliminated, d(k)，d(0)The value depends on the error of the a priori position and time if-d(k)-δ(k)+b+ε(k)Less than 0.5 milliseconds (about 150km), the rounding operation becomes 0, and so there is
All terms in the equation are known, thus eliminating the millisecond full cycle ambiguity problem in the coarse time navigation equation.
FIG. 5 is a schematic view of a scene flow for implementing an assisted navigation positioning method according to the present invention; based on the method shown in fig. 1, referring to fig. 5, the method includes:
the assisted reference station 100 extracts the assistance information 110 after receiving the GNSS signal 200 transmitted by the GNSS satellite 500;
sending the assistance information 110 to the GNSS receiving terminal 400 through the cdladio broadcast channel 300;
the assistance information 110 assists the GNSS receiving terminal 400 in performing highly sensitive navigation positioning.
FIG. 6 is a functional block diagram of a first embodiment of an aided navigation positioning system according to the present invention; referring to fig. 6, the system includes:
a signal receiving module 10, configured to receive a current GNSS signal, and when power of the current GNSS signal is smaller than a preset power and a carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio, obtain GNSS assistance information sent by a GNSS assistance reference station through a cdladio channel;
it should be noted that the fact that the power of the GNSS signal is less than the preset power and the carrier-to-noise ratio is less than the preset carrier-to-noise ratio means that under the condition of weak GNSS signal, generally, the received power is < -150dBm, and under the condition that C/N0 is less than 25dB · Hz, at this time, the ordinary satellite navigation receiver cannot work in these environments, so a high-sensitivity GNSS receiver is generally used, but the high-sensitivity GNSS receiver often needs to adopt an accumulation method to improve the signal-to-noise ratio of the captured and tracked GNSS signal, and the capturing and tracking of the GNSS signal can be completed only when the signal-to-noise ratio of the GNSS signal exceeds a certain threshold;
it is understood that the GNSS assistance information includes: the GNSS auxiliary station reference time, the GNSS auxiliary station position coordinates, the current visible star, the telegraph text of the corresponding satellite, the Doppler frequency of the satellite observed by the GNSS auxiliary station, the satellite ephemeris and the like;
an assistance information extracting module 20, configured to extract, from the GNSS assistance information, a current visible star number, a carrier doppler frequency of a satellite observed by the GNSS assistance reference station, a satellite ephemeris, position information of the GNSS assistance reference station, and a reference time; a target signal confirmation module 30, configured to, when the carrier doppler frequency, the phase of the current GNSS signal spreading code, and the current visible star meet preset conditions, capture the current GNSS signal, track the current GNSS signal in the reference time, and use the current GNSS signal in the reference time as a target GNSS signal;
understandably, the auxiliary information comprises the auxiliary reference station time, the prior position of the auxiliary station, the satellite ephemeris and information of the current visible satellite number, text, Doppler frequency and the like which can assist navigation positioning;
it should be noted that the capturing process is a process of sending the carrier doppler frequency and the telegraph text information of the current GNSS signal to the receiver through the cdraadio channel within the auxiliary reference time, and compared with a mode of sending through a mobile communication network in the prior art, the carrier doppler frequency and the telegraph text information of the GNSS signal can be timely, accurately and stably obtained by sending through the cdraadio channel according to the present invention, and the accumulation time for coherent accumulation and noncoherent accumulation can be shortened, so that the signal-to-noise ratio of the GNSS signal can be more rapidly improved;
it should be noted that the GNSS navigation signal can be represented as:
where √ 2P is the signal amplitude, D (t) is the spreading code of the current GNSS signal, C (t) is the pseudo-random noise code (PN), cos (2 π f)IFt + θ) is a carrier signal.
As can be seen from the above formula, the complete GNSS signal mainly comprises three parts, namely, the phase D (t) of the spreading code of the current GNSS signal, the PN code C (t), and the carrier cos (2 π f)IFt + θ). The carrier part of the GNSS signal can be demodulated through a carrier generated locally by a receiver, the GNSS signal after the carrier is stripped is correlated with a PN code reproduced locally, the correlated result is compared with a threshold, if the correlated result exceeds the threshold, the acquisition is considered to be successful, otherwise, the acquisition is failed; in the GNSS acquisition process, two-dimensional correlation and search are performed on a target GNSS signal in two dimensions of frequency and PN code phase, when the maximum value of a two-dimensional correlation result passes a preset threshold, acquisition is successful, and the frequency and code phase corresponding to the maximum value are initial values of carrier doppler frequency and PN code phase of the acquired GNSS signal;
in a specific implementation, when the GNSS signal is a weak signal, a maximum value obtained by one two-dimensional search often cannot pass a threshold, and the signal-to-noise ratio of the GNSS signal is often improved by a coherent and non-coherent accumulation method for a period of time. However, if the carrier-doppler frequency of the GNSS signals over the accumulation period is unknown, the receiver either takes a long time to guess and try-and-error to determine the carrier-doppler frequency of the captured GNSS signals or estimates the carrier-doppler frequency by employing a very complex signal processing model, whichever scheme does not provide the user with a satisfactory customer experience. Therefore, when weak GNSS signals are captured, the carrier Doppler frequency and the telegraph text information of the GNSS signals in the auxiliary reference time are sent to the receiver through the CDRAdio channel, and the problems can be well solved.
It should be understood that, after the GNSS signal is successfully captured, the GNSS signal which is successfully captured is tracked, multiplied by two paths of orthogonal carriers which are locally generated to complete the demodulation operation of the carrier, then respectively integrated with the instantaneous code generated by the local PN code generator, the advanced code of the advanced half chip and the lagging code of the lagging half chip, and the integrated result is transmitted to the carrier tracking loop and the code tracking loop for tracking, and the obtained tracking result is fed back to the local carrier and the local code generator for adjustment;
in a specific implementation, when the GNSS signal is a weak signal, the signal-to-noise ratio of the result of one integration is often very poor, which results in that the tracking cannot be locked or the tracking loop is out of lock, and then it is necessary to increase the input signal-to-noise ratio of the tracking loop by coherent and non-coherent accumulation methods for a period of time. However, if the navigation message of the GNSS signal is unknown during the accumulation period, it takes a long time to guess and try to make a mistake to determine the navigation message of the tracked GNSS signal, and such a method does not provide a satisfactory user experience to the user. Therefore, compared with the mobile communication transmission in the prior art, when weak GNSS signals are tracked, the auxiliary information can be timely, accurately and stably provided for the GNSS receiver through the CDRAdio channel, and the problem is solved.
A priori estimated pseudorange determination module 40, configured to determine a priori estimated pseudorange of the target GNSS signal according to the location information of the GNSS assisted reference station;
a full pseudorange generation module 50, configured to calculate expected fractional pseudoranges of each satellite according to the satellite ephemeris, the position information of the GNSS-assisted reference station, and the reference time, select one satellite as a reference satellite, and generate a full pseudorange according to the expected fractional pseudoranges of the reference satellite and the expected fractional pseudoranges of other satellites;
a position determining module 60, configured to calculate a pseudorange difference between the prior estimated pseudorange and the full pseudorange, determine a position vector of the receiver according to the pseudorange difference, and determine position information of the receiver according to the position vector of the receiver, so as to implement assisted navigation positioning.
It should be understood that the navigation information of the current GNSS signal is a continuous data stream of 50 bits per second, each satellite simultaneously transmitting to the ground the following information: each satellite individually modulates the data stream into a high frequency signal, and the data is transmitted logically divided into different pages (or frames), each page having 1500 bits, and the transmission time is 30 seconds. Each page is divided into five sub-pages (or sub-frames), each sub-page has 300 bits, and the transmission time is 6 seconds. In order to transmit a complete almanac, 25 different pages (frames) are required, i.e. 12.5 minutes. A GPS receiver is required to perform its function by receiving at least one complete almanac;
it should be noted that in the basic GNSS positioning calculation of the present embodiment, there are 4 quantities describing the state: x, y, z (position coordinates), b (common bias in pseudoranges). The specific calculation process is as follows:
the a priori state is estimated.
The pseudoranges in this state are predicted.
Actual pseudorange measurements are made.
The estimate state is adjusted based on a deviation between the expected and measured pseudoranges.
The above process can be represented by the following matrix equation:
then the current state update vector is δ x ═ δx,δy,δz,δb,δtc]T. The new matrix equation can be expressed as: δ z ═ H δ x + epsilon
Wherein,in order to be a new observation matrix,is the pseudo range rate, gamma(k)Is the velocity vector of the satellite(s),representing the clock bias rate for satellite number k;
here, thez is the measured pseudorange vector,is a predicted pseudorange vector.
For observing the matrix, where-e(k)Is the unit vector from the prior position to the direction of satellite number k.
δx＝[δx,δy,δz,δb,δtc]TRepresenting an update vector to a prior state x, y, z, b.
ε represents the measurement error ε(1)，ε(3)，…，ε(k)]T。
If there are at least 4 independent rows in H, then δ x can be solved, for example, as a least squares solution:
correspondingly, the position determining module 60 is further configured to determine whether the pseudorange difference is smaller than a preset difference, and determine whether the pseudorange difference is a required pseudorange difference; when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value; and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
It can be understood that a high-sensitivity GNSS receiver can perform positioning by solving the coarse navigation equation after acquiring at least five GNSS satellite signals, but if such coarse navigation equation is directly solved, the problem of turning by an integer millisecond exists. At present, the most common solution to the whole millisecond digital ambiguity problem is to provide a high-sensitivity GNSS receiver with position coordinates of an auxiliary reference station, satellite ephemeris and reference time, and the receiver can eliminate the whole millisecond rollover problem according to the prior information, so as to obtain the whole pseudorange of the corresponding satellite, and then obtain the positioning result of the receiver by solving the reconstructed coarse time navigation equation.
FIG. 7 is a functional block diagram of an aided navigation positioning system according to a second embodiment of the present invention; based on the method shown in fig. 6, referring to fig. 7, the system includes: the device comprises a signal receiving module 10, an auxiliary information extraction module 20, a target signal confirmation module 30, a priori estimation pseudo range determination module 40, a full pseudo range generation module 50, a position determination module 60 and a signal verification module 11;
and the signal verification module 11 is configured to verify the current GNSS signal, and if the current GNSS signal passes the verification, determine that the current GNSS signal is the required current GNSS signal. Correspondingly, the signal verification module 11 is further configured to demodulate and strip the carrier doppler frequency of the current GNSS signal according to the GNSS assistance information, correlate the demodulated and stripped GNSS signal with a local recurrence code after coherent and non-coherent accumulation, compare a result after correlation with a preset threshold value, and when the result after correlation is greater than or equal to the preset threshold value, verify that the current GNSS signal is the required current GNSS signal.
Correspondingly, the signal verification module 11 is further configured to, when the correlated result is smaller than the preset threshold value, fail the verification and re-receive the current GNSS signal.
Correspondingly, the position determining module 60 is further configured to determine whether the pseudorange difference is smaller than a preset difference, and determine whether the pseudorange difference is a required pseudorange difference;
when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value;
and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
It can be understood that, compared with the transmission mode of mobile communication in the prior art, the cdrad channel utilized in the embodiment has the advantages of high receiving sensitivity and strong anti-interference capability, and can quickly, stably and accurately transmit the auxiliary information; the pseudo-range difference obtained according to the auxiliary information is more accurate, the comparison of the pseudo-range difference and the preset difference has an obvious effect, if the positioning result is output when the pseudo-range difference is too large, the positioning result at the moment can not accurately reflect the position of the receiver at the moment, the error can be effectively avoided by comparison, and a certain screening effect is achieved.
It can be understood that, as the cdladio adopts the key technologies of LDPC channel coding, channel estimation equalization, OFDM modulation, and the like, a low reception threshold is ensured while a very low error rate is still maintained, and therefore, setting the preset threshold value according to the cdladio can relatively increase the number of the captured GNSS signals, and find the GNSS signals meeting the requirements more quickly.
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 system 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 system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. An assisted navigation positioning method, characterized in that the method comprises:
the method comprises the steps that a receiver receives a current GNSS signal, and when the power of the current GNSS signal is smaller than a preset power and the carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio, GNSS auxiliary information sent by a GNSS auxiliary reference station through a CDRAdio channel is obtained;
extracting the star number of the current visible satellite, the carrier Doppler frequency of the satellite observed by the GNSS auxiliary reference station, the satellite ephemeris, the position information of the GNSS auxiliary reference station and the reference time from the GNSS auxiliary information;
when the carrier Doppler frequency, the phase of the current GNSS signal spread spectrum code and the current visible star meet preset conditions, capturing the current GNSS signal, tracking the current GNSS signal in the reference time, and taking the current GNSS signal in the reference time as a target GNSS signal;
determining a priori estimated pseudorange of the target GNSS signal according to the position information of the GNSS auxiliary reference station;
calculating expected fraction pseudo-ranges of all satellites according to the satellite ephemeris, the position information of the GNSS auxiliary reference station and reference time, selecting one satellite as a reference satellite, and generating full pseudo-ranges according to the expected fraction pseudo-ranges of the reference satellite and the expected fraction pseudo-ranges of other satellites;
calculating a pseudo-range difference value between the prior estimated pseudo-range and the full pseudo-range, determining a position vector of the receiver according to the pseudo-range difference value, and determining position information of the receiver according to the position vector of the receiver so as to realize auxiliary navigation positioning.
2. A method as defined in claim 1, wherein after acquiring GNSS assistance information transmitted by a GNSS-assisted reference station over a cdladio channel, the method further comprises:
and verifying the current GNSS signal, and if the current GNSS signal passes the verification, determining the current GNSS signal to be the required current GNSS signal.
3. The method as claimed in claim 2, wherein said validating said assisted current GNSS signal comprises:
demodulating and stripping the carrier Doppler frequency of the current GNSS signal according to the GNSS auxiliary information, performing coherent and noncoherent accumulation on the demodulated and stripped GNSS signal, then correlating the GNSS signal with a local recurrence code, comparing the correlated result with a preset threshold value, and when the correlated result is greater than or equal to the preset threshold value, passing verification and confirming that the current GNSS signal is the required current GNSS signal.
4. The method of claim 3, wherein after comparing the correlated result to a preset threshold, the method further comprises:
and when the correlated result is smaller than the preset threshold value, the verification is failed, and the current GNSS signal is received again.
5. A method according to any of claims 1-4, wherein after said calculating a pseudorange difference between said a priori estimated pseudorange and said full pseudorange, said method further comprises:
judging whether the pseudo-range difference value is smaller than a preset difference value or not, and determining whether the pseudo-range difference value is a required pseudo-range difference value or not;
when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value;
and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
6. An assisted navigational positioning system, the system comprising:
the signal receiving module is used for receiving a current GNSS signal, and acquiring GNSS auxiliary information sent by a GNSS auxiliary reference station through a CDRAdio channel when the power of the current GNSS signal is smaller than a preset power and the carrier-to-noise ratio of the current GNSS signal is smaller than a preset carrier-to-noise ratio;
the auxiliary information extraction module is used for extracting the current visible star number, the carrier Doppler frequency of the satellite observed by the GNSS auxiliary reference station, the satellite ephemeris, the position information of the GNSS auxiliary reference station and the reference time from the GNSS auxiliary information;
a target signal confirmation module, configured to capture the current GNSS signal and track the current GNSS signal within the reference time when the carrier doppler frequency, the phase of the current GNSS signal spreading code, and the current visible star number satisfy preset conditions, and use the current GNSS signal within the reference time as a target GNSS signal;
a priori estimated pseudo-range determining module, configured to determine a priori estimated pseudo-range of the target GNSS signal according to the location information of the GNSS assisted reference station;
the full pseudo-range generation module is used for calculating the expected fraction pseudo-range of each satellite according to the satellite ephemeris, the position information of the GNSS auxiliary reference station and reference time, selecting one satellite as a reference satellite, and generating a full pseudo-range according to the expected fraction pseudo-range of the reference satellite and the expected fraction pseudo-range of other satellites;
and the position determining module is used for calculating a pseudo-range difference value between the prior estimated pseudo-range and the full pseudo-range, determining a position vector of the receiver according to the pseudo-range difference value, and determining position information of the receiver according to the position vector of the receiver so as to realize auxiliary navigation positioning.
7. The system of claim 6, wherein the system further comprises:
and the signal verification module is used for verifying the current GNSS signal, and if the current GNSS signal passes the verification, the current GNSS signal is confirmed to be the required current GNSS signal.
8. The system according to claim 7, wherein the signal verification module is further configured to demodulate and strip a carrier doppler frequency of the current GNSS signal according to the GNSS assistance information, correlate the demodulated and stripped GNSS signal with a local recurrence code after coherent and non-coherent accumulation, compare a result of the correlation with a preset threshold, and when the result of the correlation is greater than or equal to the preset threshold, verify that the current GNSS signal is the required current GNSS signal.
9. The system of claim 8, wherein the signal verification module is further configured to, when the correlated result is smaller than the preset threshold, verify that the current GNSS signal is not received again.
10. The system according to any one of claims 6 to 9, wherein the position determining module is further configured to determine whether the pseudorange difference is smaller than a preset difference, and determine whether the pseudorange difference is a required pseudorange difference;
when the pseudo-range difference value is smaller than the preset difference value, determining the pseudo-range difference value as the required pseudo-range difference value, and determining a position vector of the receiver according to the pseudo-range difference value;
and when the pseudo-range difference value is larger than or equal to the preset difference value, reselecting one satellite as the reference satellite, regenerating the full pseudo-range, and further recalculating the pseudo-range difference value.
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Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110118978B (en) * 2019-04-15 2020-05-19 中国人民解放军军事科学院国防科技创新研究院 Navigation anti-interference system and navigation anti-interference method based on low-earth-orbit satellite
CN111045052B (en) * 2019-10-14 2022-08-09 广东星舆科技有限公司 Pseudo-range differential positioning and quality control method for intelligent terminal
CN111045056B (en) * 2019-11-29 2024-04-30 交通运输部长江通信管理局 Method and device for eliminating interference satellite signals of receiver
CN114252890A (en) * 2020-09-25 2022-03-29 阿里巴巴集团控股有限公司 Positioning method, positioning device, electronic equipment and storage medium
CN114488222A (en) * 2020-10-28 2022-05-13 阿里巴巴集团控股有限公司 Positioning method, positioning device and storage medium
CN115390107B (en) * 2021-05-24 2024-12-17 阿里巴巴创新公司 Positioning method and device and position-based service providing method
CN113534197B (en) * 2021-06-10 2024-05-17 领翌技术(横琴)有限公司 Interference detection method and device for satellite positioning signals
CN113534196B (en) * 2021-07-05 2024-04-19 阳光学院 Indoor two-dimensional high-precision positioning method and system based on virtual GNSS signals
CN113466897B (en) * 2021-07-06 2024-05-17 上海方位角数据科技有限公司 Positioning resolving method and system of pseudo satellite receiver and related components thereof
CN114236576B (en) * 2021-12-13 2025-02-28 北京微纳星空科技股份有限公司 Method, device, electronic device and storage medium for determining stability of observation data
CN114302323B (en) * 2021-12-15 2023-11-07 中山大学 Indoor three-dimensional positioning time service method and system based on medium-length waves
US20230204792A1 (en) * 2021-12-23 2023-06-29 Satelles, Inc. Assisted satellite time and location
CN114444377B (en) * 2021-12-24 2024-06-21 北京理工大学 Multi-ground range finder station selecting method based on gradient elevator
CN114609652B (en) * 2022-03-11 2024-06-07 北京航空航天大学 A multi-frequency open-loop receiver tracking method and system under extreme ionospheric anomaly
CN115267842A (en) * 2022-05-25 2022-11-01 长沙金维信息技术有限公司 A kind of satellite navigation high-sensitivity signal receiving method and system
CN115201867B (en) * 2022-06-20 2025-03-28 和芯星通科技(北京)有限公司 A baseband signal processing method and device
CN115267832A (en) * 2022-08-02 2022-11-01 中国电子科技集团公司第五十四研究所 A self-organizing decentralized low-orbit satellite integrity monitoring method
CN116540268A (en) * 2023-02-03 2023-08-04 北京航空航天大学 Method and device for monitoring on-board positioning integrity
CN118091727B (en) * 2024-03-13 2024-08-02 北京中捷时代航空科技有限公司 Radio frequency switching quick positioning method and device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6417801B1 (en) * 2000-11-17 2002-07-09 Global Locate, Inc. Method and apparatus for time-free processing of GPS signals
CN103983995A (en) * 2014-04-10 2014-08-13 深圳思凯微电子有限公司 Differential positioning method and system, frequency-modulated broadcast transmitter and navigation signal receiver
CN204854760U (en) * 2015-08-13 2015-12-09 北京海尔集成电路设计有限公司 Utilize chinese digital audio broadcasting's navigation terminal

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996022546A1 (en) * 1995-01-17 1996-07-25 The Board Of Trustees Of The Leland Stanford Junior University Wide area differential gps reference system and method
CN101206258B (en) * 2007-12-20 2011-06-01 上海伽利略导航有限公司 High sensitivity auxiliary positioning system and data processing method thereof
CN101206254B (en) * 2007-12-20 2012-03-07 上海伽利略导航有限公司 Positioning method of GPS receiver locating in doors and auxiliary satellite navigation positioning system
US8085196B2 (en) * 2009-03-11 2011-12-27 Hemisphere Gps Llc Removing biases in dual frequency GNSS receivers using SBAS
CN103364758A (en) * 2012-03-28 2013-10-23 陈曦 Navigational positioning method and navigational positioning system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6417801B1 (en) * 2000-11-17 2002-07-09 Global Locate, Inc. Method and apparatus for time-free processing of GPS signals
CN103983995A (en) * 2014-04-10 2014-08-13 深圳思凯微电子有限公司 Differential positioning method and system, frequency-modulated broadcast transmitter and navigation signal receiver
CN204854760U (en) * 2015-08-13 2015-12-09 北京海尔集成电路设计有限公司 Utilize chinese digital audio broadcasting's navigation terminal

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
全球导航卫星系统辅助与增强定位技术研究;张光华;《中国博士学位论文全文数据库 信息科技辑》;20140115;第41-71页
多普勒与伪码相位值结合的A-GPS快速定位算法研究;黄志勇 等;《测绘工程》;20150331;第24卷(第3期);第31-35页

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