CN110082791B - Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method - Google Patents
Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method Download PDFInfo
- Publication number
- CN110082791B CN110082791B CN201910318415.6A CN201910318415A CN110082791B CN 110082791 B CN110082791 B CN 110082791B CN 201910318415 A CN201910318415 A CN 201910318415A CN 110082791 B CN110082791 B CN 110082791B
- Authority
- CN
- China
- Prior art keywords
- pseudo
- satellite
- correlator
- receiver
- deviation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/23—Testing, monitoring, correcting or calibrating of receiver elements
-
- 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
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
- G01S19/243—Demodulation of navigation message
Landscapes
- 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 satellite navigation signal pseudo-range deviation precise measurement and effective elimination method, which comprises the following steps: after the signals pass through the low noise amplifier and the receiving channel, the signals received by the two high-low different gain antennas are respectively divided into two paths of signals; step two: one path of the navigation signal data is collected by utilizing the navigation signal data; step three: the other path monitors satellite signal data, measures and records the result; step four: on one hand, satellite signal data are called and read, capturing, tracking and demodulating are carried out on the signal data, and pseudo-range deviation is calculated; on the other hand, the pseudo range and carrier phase measurement data are called in and read out, and the pseudo range deviation of each satellite is calculated; step five: and (5) comprehensively analyzing the result, calculating the signal pseudo-range deviation of each frequency point of each satellite, and giving out a solution. The invention can accurately measure the signal pseudo-range deviation of each frequency point of the Beidou satellite and provide effective and feasible solving measures, and solves the core scientific problem behind the bottleneck of the high-precision differential ranging technology of the influence receiver.
Description
SS technical field
The invention relates to the field of satellite navigation signal processing methods, in particular to a satellite navigation signal pseudo-range deviation precise measurement and effective elimination method.
Background
Satellite navigation takes up important roles from basic research fields (astronomy, mechanics, physics, earth dynamics and the like) to engineering technical fields (information transmission, deep space exploration, space vehicles, time transmission, speed measurement, time service and the like) and various important departments and fields (maritime work, traffic, rescue, precise agriculture, seismic monitoring, electronic communication and the like) related to national economy construction and national security. A global Navigation satellite system (GNSS, global NavigationSatellite System) provides Positioning, navigation and Timing services (PNT) to global users by transmitting downlink Navigation signals through in-orbit satellites. Wherein the satellite navigation signal acts as the only interface between the satellite navigation system and the user receiver, the limits of its intrinsic performance will directly determine the service performance limits of the entire satellite navigation system.
However, the actual ranging performance of the downlink pilot signal received by the user is determined by both the ranging capability inherent in the signal and the receiver data processing technique: the design structure of the navigation signal and the quality of signal emission determine the upper limit of the signal ranging performance; how much the potential of the signal can be put into play is determined by the level of receiver processing technology. In practical application, on one hand, because the core device loaded on the satellite cannot be completely ideal, the navigation signal actually broadcast is a product of a series of linear and nonlinear distortions of an ideal signal, when the user terminal performs positioning calculation by using the received navigation signal with distortion, a larger positioning error can occur, even a situation that the positioning is impossible occurs, and for a user with high precision requirement, disastrous results can be brought, so the distortion characteristic of the satellite transmitting signal is a root cause for causing pseudo-range deviation; on the other hand, due to different types or different manufacturers of parameters such as front-end bandwidths of user receivers or correlator intervals, different phase discrimination methods, interference resistant technologies and the like, the processing results of different receivers on the same distorted signal are inconsistent, and the pseudo-range deviation phenomenon is also caused. The pseudorange bias not only affects the pseudorange-based high-precision positioning service (especially for dual-frequency differential positioning), but also greatly affects the precision single point positioning (PPP), and the signal consistency between the same signals of different satellites greatly affects the carrier phase bias estimation (FCB) and ambiguity resolution. At present, the problem of pseudo-range deviation has become a realistic obstacle in the high-precision application of satellite navigation systems, and has restricted the further development of the high-precision application of GNSS.
Related literature has been introduced simply for pseudorange bias in the early nineties of the last century abroad, unfortunately not drawing sufficient attention. The GPS pseudorange bias problem has not received increasing attention until Wong and phenolts et al, university of stanfu 2011, find pseudorange bias in studying the ranging and positioning results of GPS and WAAS systems. In view of the severity of the pseudorange bias effects, explicit advice was given in 2013 to GPS receiver parameter settings in a GPS interface control file. However, related researches on the pseudo-range deviation of the Beidou system at home and abroad are very few so far, and the domestic on-orbit performance evaluation test team also finds the pseudo-range deviation problem in the process of developing signal test evaluation in the year 2016: the Beidou regional satellite and the test satellite have pseudo-range deviation with different degrees, and the newly transmitted Beidou third-sized global system satellite also has similar phenomena. The test results show that: when receivers of different manufacturers are connected in a zero-base line mode and output pseudo-range measurement results, the pseudo-range deviation phenomena with different sizes are found among the Beidou second satellites, the Beidou test satellites, the Beidou third satellites and different types of satellite signals after the pseudo-range measurement results are processed in a single-difference or double-difference mode and are subjected to ground monitoring and test verification, and the maximum pseudo-range deviation can reach the meter level, so that the high-precision service performance of the Beidou system is seriously affected. However, compared with a GPS system, the system has different signal systems, more satellite types, more manufacturers participating in satellite development, various user receivers, different parameter settings and the like, so that the characteristics of the pseudo-range deviation of the Beidou system and the pseudo-range deviation of the GPS system are different, deep research is required to be developed for the problem of the pseudo-range deviation of each satellite signal of the Beidou system in China, and an optimal solution is sought.
At present, the defects or technical bottlenecks existing in the research of the field at home and abroad are mainly embodied in the following aspects: firstly, the adjustment range of the pseudo-range measurement hardware parameters based on the hardware receiver is small, and the pseudo-range deviation characteristics cannot be accurately analyzed: the domestic research on the pseudo-range deviation problem is mainly carried out on the basis of a hardware receiver with a zero base line connected with an omnidirectional antenna, and because the correlator interval, the front-end bandwidth, the phase discrimination mode and the like of the hardware receiver are basically fixed when the hardware receiver leaves a factory, the adjustable parameter range of a user is very limited in the use process, so that the pseudo-range deviation characteristics of an actual satellite signal cannot be comprehensively and accurately estimated; secondly, big dipper user receiver parameter setting is very different, has further aggravated the influence of pseudo-range deviation: for the Beidou user receivers common in the current market, because the differences of the receiver correlator intervals, the filter characteristics, the front-end bandwidths, the phase discrimination modes and the like of all manufacturers are large, tracking deviation obtained by calculating the same distortion signals by different receivers is different, so that extra fixed deviation which cannot be eliminated is introduced during differential calculation, and the measurement precision of a high-precision user is seriously influenced; thirdly, the signal to noise ratio of the signal received by the omni-directional antenna receiver or the small-caliber antenna is too low to accurately reflect the real signal characteristics: because the satellite downlink signal power is submerged in noise, the user receiving antenna is generally an omni-directional antenna or an antenna with small gain, so that the signal-to-noise ratio of the satellite downlink signal received by a general user is low, and the signal distortion characteristics cannot be accurately estimated; fourth, the novel satellite navigation signal system is more complex, and the traditional analysis method cannot be used for carrying out fine analysis: at present, the Beidou three global system, the Galileo system and the GPS modernization system in China all adopt new system navigation signals, and compared with the traditional modulation mode, the new signal bandwidth is wider, the modulation mode is more complex, and higher requirements are imposed on a plurality of surfaces such as amplitude balance, phase relation among components, radio frequency compatibility, broadband gain flatness, broadband group delay flatness, amplifier nonlinearity and the like of a link. Therefore, the method has important scientific research value and practical significance for the research of precise measurement and effective solving measures of the pseudo-range deviation of the novel Beidou navigation signal.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a precise measurement technology aiming at the problem of pseudo-range deviation of novel Beidou navigation signals in China and an effective solution measure for the problem of pseudo-range deviation. Because the gain of the large-caliber antenna is high but only one satellite can be observed at the same time, the gain of the omnidirectional antenna is low but a plurality of visible in-orbit satellites can be observed at the same time; compared with the hardware receiver ranging, the software receiver technology can not only eliminate or greatly reduce common errors such as receiver clock error and measurement noise through data processing, but also realize traversal analysis processing of different parameters of the receiver by using a processing technology with higher precision and high resolution; therefore, the invention creatively combines the high-precision data processing technology of the large-caliber antenna and the weak signal capturing, tracking and ranging processing technology of the omnidirectional antenna, develops accurate modeling and deep analysis of the pseudo-range deviation generation mechanism and characteristics, and solves the technical problems that the high-precision pseudo-range observation analysis and the pseudo-range deviation elimination cannot be carried out due to the fact that the omnidirectional antenna and a hardware receiver are mainly relied on at present.
In order to solve the technical problems, the invention provides the following technical scheme:
a satellite navigation signal pseudo-range deviation precise measurement and effective elimination method comprises the following steps:
step one: the downlink signals of the navigation satellite are simultaneously received by using a high-gain large-caliber antenna and a parallel-address omnidirectional antenna, and after the signals pass through a low-noise amplifier and a receiving channel, the signals received by the two antennas are respectively divided into two paths of signals: one path of signals reach the same high-speed synchronous data acquisition equipment, the sampling frequency of the data acquisition equipment is more than or equal to 250MHz, the sampling bit number is more than or equal to 14, and the other path of signals are connected with a power divider and are respectively connected with parameter-adjustable hardware receivers of different types;
step two: the large-caliber antenna and the omnidirectional antenna receiving system respectively utilize high-speed synchronous data acquisition equipment to acquire data of navigation signals at the same time and store the navigation signals into respective data disk arrays;
step three: the hardware receiver with zero baseline connection of the large-caliber antenna and the omnidirectional antenna receiving system monitors satellite signal data at the same time, respectively adjusts the front-end bandwidth of the receiver and the interval parameters of the correlator, and continuously stores pseudo-range, carrier phase, carrier-to-noise ratio and Doppler result for at least 2 hours under the condition of each fixed parameter;
step four: and (3) data analysis processing: the software receiver is utilized to call in and read satellite signal data acquired by the synchronous data acquisition equipment, each branch signal of the navigation signal data is respectively subjected to capturing, tracking and demodulation processing, and pseudo-range deviation of the same signals of different satellites under the conditions of different correlator intervals and different front-end bandwidths is calculated;
step five: and combining the pseudo-range deviation analysis results, calculating the pseudo-range deviation of the signals of each frequency point of each satellite, and providing a pseudo-range deviation elimination solution in a targeted manner.
In a further aspect of the present invention,
the gain of the large-caliber antenna in the first step is larger than 50dBi.
In a further aspect of the present invention,
and step four, the data analysis processing also needs to utilize the pseudo range, carrier phase, carrier-to-noise ratio and Doppler data output by the hardware receiver to analyze and obtain the analysis result of the pseudo range deviation of each satellite under the conditions of different front-end bandwidths and correlator interval parameters based on the hardware receiver.
The beneficial effects are that:
(1) Based on the advantages of the large-caliber antenna, the omnidirectional antenna and the software and hardware receiver, the invention can accurately measure the pseudo-range deviation of signals of all frequency points of the Beidou satellite and provide several effective and feasible solving measures, and can solve the core scientific problem behind the bottleneck of the high-precision differential ranging technology of the receiver;
(2) The invention promotes the basic research results to be applied, so that the invention has important commercial application value for the design and optimization of GNSS user receivers in China, and has very important practical significance and urgent strategic significance for the development of aerospace industry and national defense construction industry in China.
Drawings
FIG. 1 is a schematic diagram of a process flow for carrying out data receiving and analyzing by using a large-caliber antenna;
FIG. 2 is a schematic diagram of a process flow for performing data reception and analysis using an omni-directional antenna;
FIG. 3 (a) is a schematic diagram of the mechanism for generating the pseudo-range deviation of the Beidou satellite signal and the analysis of the influence of the pseudo-range deviation on the user ranging deviation- -correlation curves of ideal signals and distorted signals;
FIG. 3 (b) is a schematic diagram showing the mechanism of generating pseudo-range bias of Beidou satellite signals and the analysis of the influence of the pseudo-range bias on user ranging bias- -tracking bias at different correlator intervals
FIG. 4 is a schematic block diagram of pseudorange bias analysis;
fig. 5 (a) is a graph of the maximum value of the pseudo range deviation-color temperature of the beidou satellite No. two B1I signal under the conditions of different correlator intervals and different front-end bandwidths;
FIG. 5 (B) is a graph of the maximum value of the pseudorange bias, a contour plot, of the Beidou second satellite B1I signal under different correlator intervals and different front end bandwidths;
fig. 6 (a) is a graph of the maximum value of the pseudo range deviation-color temperature of the beidou satellite No. two B3I signal under the conditions of different correlator intervals and different front-end bandwidths;
FIG. 6 (B) is a graph of the maximum value of the pseudorange bias, a contour plot, of the Beidou No. two satellite B3I signal under different correlator intervals and different front end bandwidths;
Detailed Description
Step one: and (5) receiving signals.
As shown in fig. 1 and 2. Firstly, a large-caliber antenna with higher gain (the gain is more than 50 dBi) and a parallel-address omnidirectional antenna are utilized to simultaneously receive downlink signals of a navigation satellite, and in order to improve the reliability and the analysis precision of an analysis result, the position of the antenna needs to be ensured to be free from the influence of other larger electromagnetic interference as much as possible.
After satellite downlink signals received by the antennas pass through the low noise amplifier and the receiving channel, the signals received by the two antennas are respectively divided into two paths of signals: one path of signal reaches the same synchronous data acquisition equipment to realize synchronous data acquisition of the Beidou satellite B1/B2/B3 frequency point signals (for higher-precision offline analysis, the sampling frequency is more than or equal to 250MHz, and the sampling bit number is more than or equal to 14); the other path of signal is divided into N paths through a power divider and is respectively connected with parameter-adjustable hardware receivers of different models, and the front-end bandwidth of the receiver and the interval parameters of a correlator can be respectively adjusted before signal monitoring;
step two: data acquisition and storage, as shown in fig. 1 and 2.
(1) And (3) high-precision data acquisition: the navigation signal enters the synchronous data acquisition equipment to acquire data and is stored in the data disk array. The large-caliber antenna and the omnidirectional antenna receiving system respectively utilize synchronous data acquisition equipment to acquire data of navigation signals at the same time and store the navigation signals into respective data disk arrays;
(2) Hardware receiver data acquisition: the hardware receiver with zero baseline connection of the large-caliber antenna and the omnidirectional antenna receiving system monitors satellite signal data at the same time, respectively adjusts the front-end bandwidth of the receiver and the interval parameters of the correlator, and continuously stores pseudo-range, carrier phase, carrier-to-noise ratio and Doppler result for at least 2 hours under the condition of each fixed parameter;
step three: and (3) data analysis processing:
high-precision collected data analysis method
The satellite signal data acquired by the synchronous data acquisition equipment is tuned in and read by the software receiver, each branch signal of the navigation signal data is respectively captured, tracked and demodulated after preprocessing, and then the pseudo-range deviation of the same signal of different satellites under the conditions of different correlator intervals and different front-end bandwidths is analyzed and calculated. The specific evaluation method is as follows:
after the satellite navigation signal is generated on the satellite, the satellite navigation signal needs to pass through a satellite transmitting channel, a space propagation environment and a user terminal receiving channel and then reaches a user receiver analysis processing unit to carry out positioning calculation processing. However, each link may not be a pure ideal transmission channel, and may cause some distortion of the satellite navigation signal. Because the user terminal mainly performs positioning and ranging based on the correlation peak between the received signal and the local reproduction signal, when the distorted navigation signal and the local reproduction code of the receiver perform correlation operation, the correlation peak curve is distorted, so that tracking and ranging results are affected, positioning accuracy is finally affected, and a larger error is generated in severe cases, as shown in fig. 3 (a). It is apparent that the correlation curve of the distorted signal has a more serious distortion and asymmetry than the ideal correlation curve.
Ideally, the zero crossing point of the receiver code tracking loop phase discrimination curve (S curve) should be located at the position where the code tracking error is zero, and in practical application, due to the influence of channel transmission distortion, multipath, noise and the like, the locking point of the receiver code tracking loop generates deviation.
Several common receiver code tracking loop phase detectors mainly include: incoherent lead-lag amplitude phase detector, incoherent lead-lag power phase detector, quasi-coherent dot product power phase detector, and coherent dot product power phase detector. The invention introduces an S-curve zero-crossing deviation analysis method aiming at various common code tracking loop phase detectors.
Let the distance between the lead correlator and the lag correlator be delta, the unit be chip, and the instant correlator output be P 0 The advanced correlator output isThe hysteresis correlator output is +.>The S-curve calculation method of the different code tracking loop phase detector is as follows:
incoherent lead-lag amplitude phase discriminator
Incoherent lead-lag power phase discriminator
This approach is adopted by most receivers.
Quasi-coherent dot product power phase discriminator
The dot product power phase detector does not utilize the output of three correlators compared to a lead-minus-lag phase detector: instant correlator output P, early correlator output E and late correlator output L, but instant I using I branches directly P Lead I E And hysteresis I L Coherent integration data and instantaneous Q of Q branch P Advanced Q E And lag Q L Phase discrimination is carried out on coherent integration results, and subscripts in formulasRepresenting either leading or lagging chip spacing. This approach requires more correlators.
Coherent dot product power phase discriminator
The coherent dot product power phase discrimination method is simplest, the calculated amount of the receiver is minimum, but the signal power is required to be concentrated on an I branch: if the receiver carrier loop adopts a phase-locked loop and works in a steady-state area, the requirements can be met. However, if the receiver carrier loop is a frequency locked loop, or the phase locked loop is not yet stable, part of the signal power will be lost in the Q branch, and the performance of the phase detector will be reduced.
After the S curve is calculated by the method, the deviation epsilon of the locking point is obtained bias The calculation method (delta) is as follows:
SCurve(ε bias (δ),δ)＝0 (5)
drawing the deviation epsilon of the locking point of the phase discrimination curve of the received signal Bias The variation curve of (delta) along with the lead-lag distance delta can obtain the S-curve zero crossing point deviation curve SCurve under different correlator interval conditions Bias (delta); similarly, the deviation epsilon of the locking point of the phase discrimination curve of the received signal is drawn Bias (band) along with the change curve of the front-end bandwidth band of the receiver, so as to obtain an S-curve zero crossing point deviation curve SCurve under the front-end bandwidth condition Bias (band). The distance measurement deviation calculated at this time is nanosecond, and the distance measurement deviation in meters is obtained by multiplying the speed of light. Fig. 3 (b) shows the tracking bias calculated from the ideal correlation curve and the distorted signal correlation curve in fig. 3 (a). The influence and the influence degree of signal distortion on the ranging of the user can be intuitively seen from the figure.
The pseudorange bias is the difference between the user receiver measurement error and the reference receiver measurement error as shown in fig. 4. Thus, the calculation results in that the user can operate under the conditions of different correlator intervals or different front-end bandwidthsAfter the S-curve zero crossing deviation curve, the distance measurement deviation SCurve under the condition of fixed reference receiver parameters needs to be subtracted Bias (δ 0 ，band 0 ) The pseudorange bias measurements under certain reference receiver parameter settings are obtained.
Method for analyzing collected data of hardware receiver
The pseudorange observation equation may be expressed as follows:
wherein subscript i, j denotes satellite, B k For the frequency point of the Beidou No. two satellite signals (k takes the values of 1,2 and 3), subscripts m and n represent receivers,for pseudo-range observations>For a theoretical distance δt m For receiver clock skew δt i For satellite clock error, IFB m Tgd for receiver inter-frequency difference i Is the difference between satellite frequencies, c is the speed of light, < >>For ionospheric delay, +.>In order for the tropospheric delay to be sufficient,delay for relativistic effects, < >>For pseudorange measurement bias (i.e. receive channel delay),>is thermal noise, MP m i Representing multipath error +.>Is the error caused by signal distortion.
In order to reduce the influence of ground multipath and interference as much as possible, it is required that the circumferences of the large-caliber antenna and the omni-directional antenna are not shielded and that the electromagnetic environment is clean, so that the influence of ground multipath can be considered to be avoided. Because of the zero-base line connection between the receivers, the ionospheric delay, tropospheric delay and relativistic effect delay of the same satellite signals received by each receiver can be considered to be the same. Therefore, when O-C double difference processing is carried out on pseudo-range observation values of two receivers, error items such as receiver clock difference, satellite clock difference, receiver frequency difference, satellite frequency difference, ionospheric delay, tropospheric delay, relativistic effect delay and the like can be eliminated, and pseudo-range deviation is obtained.
(1) Single frequency user
Since the receiver front-end bandwidth settings are approximately the same, the pseudorange bias analysis results are not significantly affected, and there are mainly the following possibilities only when the correlator intervals are different:
(1) two receivers (different correlator intervals) observe one satellite at the same time, and perform single difference processing:
(2) two receivers (different correlator intervals) observe two satellites simultaneously, and perform double difference processing:
wherein the method comprises the steps of
Where m and n denote receivers and i and j denote satellites. Signal distortionIs generally constant, +.>And->The pseudo-range deviation caused by the signal distortion is smaller than the pseudo-range deviation caused by the signal distortion, and the pseudo-range deviation is zero-mean noise distribution, so that the signal distortion can be obtained through a mode of averaging for a period of time (a plurality of hours).
(3) Two receivers (same correlator interval) observe a satellite at the same time, and do single difference processing:
it can be seen that both multipath and signal distortion are now counteracted by the differential processing.
(4) Two receivers (same correlator interval) observe two satellites simultaneously, and do double difference processing:
only noise remains at this point and can be considered zero-mean distribution.
(2) Dual-band user
Assuming that the receivers m and n receive the B1/B3 dual-frequency signals of the ith satellite and the jth satellite at the same time, a pseudo-range observation equation without ionosphere combination, which is often adopted in dual-frequency positioning, can be expressed as follows:
it can be found that the pseudo-range measurement bias of the B1 frequency point is amplified by about 2.9 times when the two frequencies are combined, and the B3 frequency point is amplified by about 1.9 times; the double frequency linearly combined pseudorange measurement error will be amplified by a factor of about 3.5. If the pseudo-range measurement deviation signs of the two frequency points are opposite, the pseudo-range deviation of the double-frequency combination is the most serious.
The research results show that: when the parameter settings between the receivers are different, the ranging deviation caused by signal distortion, multipath and thermal noise cannot be eliminated no matter whether the single-difference or double-difference processing is performed; if the parameter settings of the two receivers are the same, the single-difference or double-difference processing can eliminate the influence of signal distortion and multipath, and only the influence of noise remains after the double-difference processing; if the distortion characteristics of the satellite signals are completely consistent or the parameter settings of the receivers are completely the same, the pseudo-range deviation phenomenon caused by the satellite signal distortion or the difference of the receiver parameters can be completely eliminated when double-difference processing is performed. In practice, the distortion of the downlink signals transmitted by the satellites is unlikely to be completely consistent, so that pseudorange measurement bias occurs between receivers with different configurations.
Step five: pseudo-range bias mitigation solution:
from the above, it can be seen that the pseudorange bias is in fact a relative value, which is the pseudorange difference between the user receiver and the reference receiver, or between the user receivers. In general, the differential enhancement user uses differential correction information output by the reference receiver of the zero baseline connection to improve the positioning result, thereby achieving the enhancement purpose. Therefore, the pseudo-range deviation is based on a certain reference receiver configuration, and if the parameter settings between the reference receiver and the user receiver are not matched, different pseudo-range deviations can be obtained from different reference receiver parameter settings and different user receiver parameter settings.
In order to reduce the pseudorange bias, an effective and feasible approach is to minimize the parameter set range of the user receiver as close as possible to the parameter value of the reference receiver. GPS is a well-defined method of defining receiver parameter settings in its ICD. Another possible approach is to ensure consistency of the various manufacturer receiver parameter settings as much as possible without requiring the user receiver to match as much as possible with the reference receiver parameters, since the same receiver parameters can eliminate errors due to signal distortion or multipath when single or double difference processing is performed. The solutions of the two methods are basically consistent, and the range of the values of the parameters of the receiver is limited from the angle of the user. Yet another approach is to constrain and adjust the on-board signal starting from the root of the pseudorange bias generation: on one hand, the consistency between the same signals broadcast by different satellites is ensured as much as possible, on the other hand, the satellite side is required to be capable of adjusting the signals transmitted by the satellites, and signal distortion caused by non-ideal characteristics of a satellite transmitting channel is compensated by means of on-board predistortion parameter uploading and the like. The method has higher technical requirements and higher implementation difficulty, and needs to adjust the on-board equipment, so that a more effective and feasible scheme is to restrict the parameters of the receiver.
Assume that the parameter settings of the Beidou B1 and B3 frequency point reference receivers are respectively: 0.5 chip interval and 20MHz bilateral bandwidth, 1.0 chip interval and 50MHz bilateral bandwidth. Fig. 5 and 6 show a color temperature map, a contour map and a suggested range of receiver parameters of the maximum value of the pseudo-range deviation of the Beidou actual measurement B1I and B3I signals. The receiver correlator spacing and front-end bandwidth within the rectangular box of the figure are the proposed range of values. The research results show that: when the user receiver parameter setting is relatively close to the reference receiver parameter setting, the solution provided by the invention can theoretically reduce the maximum pseudo-range deviation to be within 20cm or 10cm, thereby further ensuring the high-precision and high-reliability service of the Beidou system.
Although the invention has been described hereinabove with reference to certain embodiments, various modifications can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention, and in particular, the features of the various embodiments missed by the present invention can be used in any combination, provided that there is no technical conflict, and the lack of description of such combinations in this invention is merely for the sake of brevity and economy of resources. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed herein, but that the invention will include the claims appended hereto.
Claims (3)
1. A satellite navigation signal pseudo-range deviation precise measurement and effective elimination method is characterized by comprising the following steps:
step one: the downlink signals of the navigation satellite are simultaneously received by using a high-gain large-caliber antenna and a parallel-address omnidirectional antenna, and after the signals pass through a low-noise amplifier and a receiving channel, the signals received by the two antennas are respectively divided into two paths of signals: one path of signals reach the same high-speed synchronous data acquisition equipment, the sampling frequency of the data acquisition equipment is more than or equal to 250MHz, the sampling bit number is more than or equal to 14, and the other path of signals are connected with a power divider and are respectively connected with parameter-adjustable hardware receivers of different types;
step two: the large-caliber antenna and the omnidirectional antenna receiving system respectively utilize high-speed synchronous data acquisition equipment to acquire data of navigation signals at the same time and store the navigation signals into respective data disk arrays;
step three: the hardware receiver with zero baseline connection of the large-caliber antenna and the omnidirectional antenna receiving system monitors satellite signal data at the same time, respectively adjusts the front-end bandwidth of the receiver and the interval parameters of the correlator, and continuously stores pseudo-range, carrier phase, carrier-to-noise ratio and Doppler result for at least 2 hours under the condition of each fixed parameter;
step four: and (3) data analysis processing: the software receiver is utilized to call in and read satellite signal data acquired by the synchronous data acquisition equipment, each branch signal of the navigation signal data is respectively subjected to capturing, tracking and demodulation processing, and pseudo-range deviation of the same signals of different satellites under the conditions of different correlator intervals and different front-end bandwidths is calculated;
the specific process of data analysis processing is as follows: let the distance delta between the leading correlator and the lagging correlator be given in the unit of chip, and the instant correlator output be P 0 The advanced correlator output isThe hysteresis correlator output is +.>The calculation method of the S-curve SCurve (epsilon, delta) of the different code tracking loop phase detectors is as follows:
incoherent lead-lag amplitude phase detector:
incoherent lead-lag power phase detector:
similar coherent dot product power phase detector:
the dot product power phase detector does not utilize the output of three correlators compared to a lead-minus-lag phase detector: instant correlator output P, early correlator output E and late correlator output L, but instant I using I branches directly P Lead I E And hysteresis I L Coherent integration data and instantaneous Q of Q branch P Advanced Q E Sum of lags Q L Phase discrimination is carried out on coherent integration results, and subscripts in formulasA chip interval representing either lead or lag;
coherent dot product power phase discriminator
After the S curve is calculated by the method, the deviation epsilon of the locking point is obtained bias The calculation method (delta) is as follows:
SCurve(ε bias (δ),δ)＝0
drawing the deviation epsilon of the locking point of the phase discrimination curve of the received signal Bias The variation curve of (delta) along with the lead-lag distance delta can obtain the S-curve zero crossing point deviation curve SCurve under different correlator interval conditions Bias (delta); similarly, the deviation epsilon of the locking point of the phase discrimination curve of the received signal is drawn Bias (band) along with the change curve of the front-end bandwidth band of the receiver, so as to obtain an S-curve zero crossing point deviation curve SCurve under the front-end bandwidth condition Bias (band)；
After calculating S-curve zero crossing point deviation curve of user under different correlator intervals or different front end bandwidths, the distance measurement deviation under fixed reference receiver parameter condition needs to be subtracted
SCurve Bias (δ 0 ，band 0 ) Obtaining a pseudo-range deviation measurement result under a certain reference receiver parameter setting condition;
when O-C double difference processing is carried out on pseudo-range observation values of two receivers, receiver clock difference, satellite clock difference, receiver frequency difference, satellite frequency difference, ionospheric delay, tropospheric delay and relativistic effect delay error items can be eliminated, and pseudo-range deviation is obtained;
single frequency user:
since the receiver front-end bandwidth settings are approximately the same, the pseudorange bias analysis results are not significantly affected, and there are mainly the following possibilities only when the correlator intervals are different:
(1) two receivers observe a satellite at different correlator intervals simultaneously, and perform single difference processing:
(2) two satellites are observed simultaneously by two receivers at different correlator intervals, and double difference processing is carried out:
wherein the method comprises the steps of
Where m and n represent receivers, i and j represent satellites, and signal distortionIs generally constant, +.>ε ij ρ,mn And MP ij ρ,mn Compared with signal distortion->The pseudo-range deviation is small and is zero-mean noise distribution, so that the signal distortion can be obtained in a time-averaged mode;
B k for the frequency point of the Beidou No. two satellite signals, the k takes the values of 1,2 and 3,for pseudo-range observations>For a theoretical distance δt m For receiver clock skew δt i For satellite clock difference, c is light speed, < +.>For pseudorange measurement bias, i.e. receive channel delay,/->Is thermal noise, MP m i Representing multipath errors, SErro m i Errors caused by signal distortion;
(3) the two receivers observe a satellite at the same time with the same correlator interval, and perform single difference processing:
(4) two receivers (same correlator interval) observe two satellites simultaneously, and do double difference processing:
(2) Dual-band user
Assuming that the receivers m and n receive the B1/B3 dual-frequency signals of the ith satellite and the jth satellite at the same time, a pseudo-range observation equation without ionosphere combination, which is often adopted in dual-frequency positioning, can be expressed as follows:
step five: and combining the pseudo-range deviation analysis results, calculating the pseudo-range deviation of the signals of each frequency point of each satellite, and providing a pseudo-range deviation elimination solution in a targeted manner.
2. The method for precisely measuring and effectively eliminating the pseudorange bias of a satellite navigation signal according to claim 1, wherein the gain of the large-caliber antenna in the first step is greater than 50dBi.
3. The method for precisely measuring and effectively eliminating the pseudo-range deviation of the satellite navigation signal according to claim 1, wherein the data analysis in the fourth step is to analyze and obtain the analysis result of each satellite pseudo-range deviation based on different front-end bandwidths and correlator interval parameters of the hardware receiver by using the pseudo-range, carrier phase, carrier-to-noise ratio and Doppler data output by the hardware receiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910318415.6A CN110082791B (en) | 2019-04-19 | 2019-04-19 | Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910318415.6A CN110082791B (en) | 2019-04-19 | 2019-04-19 | Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110082791A CN110082791A (en) | 2019-08-02 |
| CN110082791B true CN110082791B (en) | 2023-09-12 |
Family
ID=67415629
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910318415.6A Active CN110082791B (en) | 2019-04-19 | 2019-04-19 | Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110082791B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110445557B (en) * | 2019-08-13 | 2021-08-20 | 中国人民解放军63920部队 | Deep space measurement and control interferometry large-aperture antenna pointing calibration method and device |
| CN111190197B (en) * | 2020-01-16 | 2022-10-28 | 中国人民解放军63921部队 | Navigation satellite signal quality on-orbit optimization and maintenance method |
| CN111323798B (en) * | 2020-03-24 | 2021-04-09 | 中国科学院国家空间科学中心 | GNSS occultation ionosphere error correction method and system based on ionosphere observation data |
| CN111596322B (en) * | 2020-05-20 | 2022-12-23 | 中国电子科技集团公司第二十研究所 | Receiver pseudo-range measurement consistency evaluation method under short baseline condition |
| CN111812685B (en) * | 2020-06-22 | 2023-04-28 | 泰斗微电子科技有限公司 | Signal tracking positioning deviation determining method and device |
| CN111856526B (en) * | 2020-07-24 | 2022-04-08 | 上海交通大学 | Method, system and medium for identifying non-direct path satellite navigation signal |
| CN112462399A (en) * | 2020-10-22 | 2021-03-09 | 中国科学院空天信息创新研究院 | Receiver-based pseudo-range deviation calculation and correction method and device |
| CN112566237B (en) * | 2020-11-30 | 2022-11-15 | 中国科学院国家授时中心 | Time synchronization method based on multi-node networking |
| CN113075702B (en) * | 2021-03-25 | 2023-04-25 | 杭州星辰大海科技有限公司 | Unmanned aerial vehicle defense high-precision time service method and system based on pseudolite technology |
| CN113281796B (en) * | 2021-07-23 | 2021-10-15 | 腾讯科技（深圳）有限公司 | Position determining method, speed determining method, device, equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101738598A (en) * | 2008-11-19 | 2010-06-16 | 中国科学院国家天文台 | Method for performing real-time measurement on track and position of satellite or aircraft |
| CN103033824A (en) * | 2012-12-18 | 2013-04-10 | 中国科学院国家授时中心 | High-performance navigational satellite space signal quality assessment method |
| CN104765043A (en) * | 2015-03-17 | 2015-07-08 | 广东工业大学 | High-integration satellite navigation continuously-operating reference station |
| WO2016188028A1 (en) * | 2015-05-27 | 2016-12-01 | 中国科学院嘉兴微电子与***工程中心 | Assisted acquisition method in combined navigation receiver |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10775510B2 (en) * | 2016-06-06 | 2020-09-15 | Brian G. Agee | Blind despreading of civil GNSS signals for resilient PNT applications |
-
2019
- 2019-04-19 CN CN201910318415.6A patent/CN110082791B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101738598A (en) * | 2008-11-19 | 2010-06-16 | 中国科学院国家天文台 | Method for performing real-time measurement on track and position of satellite or aircraft |
| CN103033824A (en) * | 2012-12-18 | 2013-04-10 | 中国科学院国家授时中心 | High-performance navigational satellite space signal quality assessment method |
| CN104765043A (en) * | 2015-03-17 | 2015-07-08 | 广东工业大学 | High-integration satellite navigation continuously-operating reference station |
| WO2016188028A1 (en) * | 2015-05-27 | 2016-12-01 | 中国科学院嘉兴微电子与***工程中心 | Assisted acquisition method in combined navigation receiver |
Non-Patent Citations (1)
| Title |
|---|
| Nonlinear observer for inertial navigation aided by pseudo-range and range-rate measurements;Tor A. Johansen等;《2015 European Control Conference》;20151123;第1673-1680页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110082791A (en) | 2019-08-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110082791B (en) | Satellite navigation signal pseudo-range deviation precise measurement and effective elimination method | |
| Hauschild et al. | A study on the dependency of GNSS pseudorange biases on correlator spacing | |
| US8456353B2 (en) | Method and system for determining clock corrections | |
| OBrien et al. | Mitigation of adaptive antenna induced bias errors in GNSS receivers | |
| US6603803B1 (en) | Global positioning system receiver for monitoring the satellite transmissions and for reducing the effects of multipath error on coded signals and carrier phase measurements | |
| CN109100757A (en) | A kind of method for evaluating quality of New Satellite navigation signal | |
| CN112180410A (en) | Navigation signal pseudo-range deviation correction method | |
| US8907844B2 (en) | Dual frequency receiver for satellite based positioning and associated method of reception | |
| CN111190198B (en) | Satellite receiver of GBAS test equipment and pseudo-range generation method and system thereof | |
| Wong et al. | Alternative characterization of analog signal deformation for GNSS-GPS satellites | |
| Hobiger et al. | GLONASS-R: GNSS reflectometry with a frequency division multiple access-based satellite navigation system | |
| Guo et al. | Impact of the third frequency GNSS pseudorange and carrier phase observations on rapid PPP convergences | |
| Zhang et al. | GPS receiver phase biases estimable in PPP-RTK networks: dynamic characterization and impact analysis | |
| Simsky et al. | Performance assessment of Galileo ranging signals transmitted by GSTB-V2 satellites | |
| Thoelert et al. | A multi-technique approach for characterizing the SVN49 signal anomaly, part 2: chip shape analysis | |
| Blanco-Delgado et al. | Multipath analysis using code-minus-carrier for dynamic testing of GNSS receivers | |
| Sadrieh et al. | Doppler characterization of a mobile GNSS receiver in multipath fading channels | |
| Huang et al. | Navigation domain multipath characterization using GNSS direct position estimation in urban canyon environment | |
| Krzan et al. | Low-cost GNSS antennas in precise positioning: a focus on multipath and antenna phase center models | |
| Li et al. | Analysis on the influence of BeiDou satellite pseudorange bias on positioning | |
| Jin et al. | Two-step unbiased estimation on small-delay multipath of GNSS signals based on S-curve bias | |
| Pan et al. | Machine learning-based multipath modelling in spatial-domain: a demonstration on GNSS short baseline processing | |
| Nayak et al. | GPS Receiver Simplification for Low-cost Applications and Multipath Mitigation Analysis on SDR-based Re-configurable Software Receiver. | |
| Vagle et al. | Performance of antenna array calibration in multipath environments | |
| Hahn | Spatial and Polarization Domain-Based GNSS Processing for Multipath Mitigation using a Dual-Polarized Antenna Array |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |