CN105445765B - A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation - Google Patents
A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation Download PDFInfo
- Publication number
- CN105445765B CN105445765B CN201510854630.XA CN201510854630A CN105445765B CN 105445765 B CN105445765 B CN 105445765B CN 201510854630 A CN201510854630 A CN 201510854630A CN 105445765 B CN105445765 B CN 105445765B
- Authority
- CN
- China
- Prior art keywords
- mrow
- pseudo
- msub
- range
- satellite
- 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.)
- Expired - Fee Related
Links
- 238000000691 measurement method Methods 0.000 title claims abstract description 18
- 230000001360 synchronised effect Effects 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims description 15
- 230000000630 rising effect Effects 0.000 claims description 13
- 238000012937 correction Methods 0.000 claims description 12
- 230000005540 biological transmission Effects 0.000 claims description 11
- 238000004364 calculation method Methods 0.000 claims description 8
- 238000009499 grossing Methods 0.000 claims description 4
- 230000001960 triggered effect Effects 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims 1
- DMBHHRLKUKUOEG-UHFFFAOYSA-N diphenylamine Chemical compound C=1C=CC=CC=1NC1=CC=CC=C1 DMBHHRLKUKUOEG-UHFFFAOYSA-N 0.000 abstract 1
- 241000577395 Thenus Species 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009432 framing Methods 0.000 description 2
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
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
- G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
-
- 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
- G01S19/35—Constructional details or hardware or software details of the signal processing chain
- G01S19/37—Hardware or software details of the signal processing chain
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Signal Processing (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The invention discloses a kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation, the D2 navigation messages that it broadcasts for Beidou navigation satellite system earth GEO satellite are different from the D1 navigation message speed that non-GEO satellite is broadcast, cause the synchronous head interval of subframe different, at the whole second that can not be in the Big Dipper the problem of synchronism output pseudorange, utilize the thought of fuzzy control, on the basis of the IGSO satellite pseudorange transfer times, fuzzy control rule is set, the output of GEO satellite pseudorange is modified and estimated, realizes that pseudorange synchronism output positions time service with receiver.
Description
Technical Field
The invention relates to a pseudo-range measurement method, in particular to a pseudo-range measurement method of a mixed constellation of a Beidou navigation satellite system, and belongs to the technical field of satellite navigation.
Background
The Beidou navigation satellite system is a global navigation satellite system integrating basic navigation service and differential integrity service built in China, the space section adopts mixed constellation layout and consists of 5 geostationary orbit satellites (GEO), 3 inclined synchronous orbit satellites (IGSO) and 27 medium and high orbit satellites (MEO), the orbit height of the GEO satellite is 35786 kilometers, and the GEO satellite is respectively fixed at 58.75 degrees E, 80 degrees E, 110.5 degrees E, 140 degrees E and 160 degrees E; the MEO satellite orbit height is 21528 kilometers, and the orbit inclination angle is 55 degrees; the height of the IGSO satellite orbit is 35786 kilometers, and the inclination angle of the orbit is 55 degrees.
In 2012, a regional navigation system consisting of 5 GEO satellites, 5 IGSO satellites and 4 MEO satellites starts to provide positioning and time service for china and surrounding areas, and has generated wide economic and social benefits in many fields such as traffic transportation, marine fishery, hydrological monitoring, weather forecasting, geodetic surveying, intelligent driving investigation, disaster relief and reduction, mobile phone navigation, vehicle-mounted navigation and the like. 3, 30 months in 2015, the first new generation of Beidou navigation satellites are successfully transmitted, the successful transmission of the satellites marks the starting implementation of a Beidou navigation system from regional operation to global expansion, the new generation of Beidou satellites can carry out experimental verification work such as a satellite-borne hydrogen atomic clock, an inter-satellite link, a novel navigation signal system and the like, and the basic service is provided for the country with one path in 2018; the global service capability is formed in 2020, and an international first-class global satellite navigation system is built.
The Beidou IGSO satellite and the MEO satellite broadcast D1 navigation messages, and the D1 navigation messages consist of superframes, main frames and subframes. Each superframe is 36000 bits and lasts for 12 minutes, and each superframe consists of 24 main frames; each main frame is 1500 bits and lasts for 30 seconds, and each main frame consists of 5 subframes; each subframe is 300 bits and lasts for 6 seconds, and each subframe consists of 10 words; each word is 30 bits for 0.6 seconds. The Beidou GEO broadcasts a D2 navigation message, and the D2 navigation message consists of a superframe, a main frame and a subframe. Each superframe is 180000 bits for 6 minutes, and each superframe is composed of 120 main frames; each main frame is 1500 bits and lasts for 3 seconds, and each main frame consists of 5 subframes; each subframe is 300 bits and lasts for 0.6 second, and each subframe consists of 10 words; each word is 30 bits for 0.06 seconds.
Compared with the D2 navigation message, the rising edge of the sub-frame head of the D1 navigation message is aligned with the whole second of the Beidou, and the two sub-frame heads are separated by 6 seconds; the speed of the D2 navigation message is 10 times of that of the D1 navigation message, the time between two adjacent subframe heads is 0.6 second, and the second time corresponding to the second counting in the week is the time corresponding to the first pulse rising edge of the synchronization head of the current main frame 1, which means that the rising edges of the subframe heads are not all aligned with the whole second of the Beidou. The layout of the mixed constellation and the broadcasting of different navigation messages increase the complexity of pseudo range measurement and receiver clock error correction in a real-time receiver, and the traditional pseudo range latch integral second signal aligned with the system time is not directly applicable any more. The solution idea of the hardware level comprises the steps of improving the frequency of pseudo-range latch signals, adopting two sets of pseudo-range latch signals and the like, and increasing the pressure and complexity of hardware operation.
The Beidou GEO satellite is fixed on a geosynchronous orbit above the equator, the IGSO and the GEO orbit have the same height, and the intersatellite point is a big 8-shaped track which takes the equator as a central point and is in the north-south direction. Theoretical analysis and experimental verification of effective coverage areas of the Beidou IGSO and the GEO show that although pseudo-range propagation time changes in real time due to satellite motion, receiver motion and the like, the IGSO close to the GEO position is used as a reference, the difference between the pseudo-range propagation time and the GEO position does not exceed 10ms, and the basis is laid for the application of fuzzy control.
The fuzzy control system is a computer digital control system based on fuzzy aggregation, fuzzy linguistic variable and fuzzy logic reasoning, the fuzzy control belongs to the category of nonlinear control and intelligent control, and the fuzzy controller summarizes experience and experimental results into a plurality of rules and carries out reasoning according to the rules to quickly complete operation. The ideal output result can be obtained by selecting a proper fuzzy model and formulating a proper rule. The principle of the method can be divided into four processes of fuzzification, fuzzy rule, fuzzy reasoning and defuzzification.
Disclosure of Invention
The invention aims to solve the technical problem of providing a pseudo-range measurement method of a Beidou navigation system mixed constellation aiming at the defects of the background technology, which solves the problem of pseudo-range output asynchronism caused by different navigation messages broadcast by a Beidou GEO satellite and a non-GEO satellite, and realizes synchronous output of pseudo-range, receiver positioning and receiver clock error correction.
A pseudo-range measurement method for a mixed constellation of a Beidou navigation satellite system specifically comprises the following steps:
step 1, powering on and resetting a receiver, and randomly generating a pseudo-range latch signal TIC with adjustable rising edge position in the receiver;
step 2, generating a local ranging code and a carrier, capturing a satellite signal, and enabling the successfully captured signal to enter a tracking channel;
step 3, respectively carrying out bit synchronization and subframe synchronization on the GEO satellite, the IGSO satellite and the MEO satellite;
step 4, after sub-frame synchronization of each channel is realized, switching to a pseudo-range output and ephemeris demodulation mode, and further calculating initial pseudo-range propagation time, satellite position and pseudo-range correction parameters, wherein after the IGSO satellite and MEO satellite channels realize bit synchronization, frame synchronization second-integer pulse signals are triggered, and pseudo-range output at the Beidou second-integer position is realized;
step 5, selecting the pseudo-range propagation time of the IGSO satellite calculated in the step 4 as a reference tρ,IGSO_rPseudo-range transmission time t for GEO satellitesρ,GEOCorrecting;
step 6: correcting pseudo-range propagation time of the GEO satellite channel by adopting a fuzzy control rule to obtain pseudo-range propagation time t synchronous with IGSOρ,GEO_cor；
Step 7, obtaining an initial pseudo range rho according to the pseudo range propagation time, and smoothing the pseudo range by adopting a carrier phase:
where ρ iss,kFor the smoothed pseudorange, phi, at the current timekIs the carrier phase, p, at the current times,k-1Smoothed by the last time instant of the pseudorange, phik-1Is the carrier phase, p, of the previous time instantkThe pseudo range which is not smoothed at the current moment is M, and the time constant is smoothed;
and 8, calculating the clock error of the receiver by positioning the receiver, calculating the control quantity of the pseudo-range latch signal, and further correcting the position of the pseudo-range latch signal, wherein the specific calculation formula is as follows:
NTIC,k＝NTIC,k-1+(Δu-ΔtTIC_frame)*fc/c
in the above formula,. DELTA.uClock error residual, Δ t, obtained for receiver positioningTIC_frameFixed delay for channel frame synchronization, NTIC,kIs the control quantity of TIC at the present moment, NTIC,k-1Control quantity of TIC at the previous time, fcSampling frequency for TIC;
and 9, after the receiver realizes primary positioning, correcting the TIC pulse to be aligned with the Beidou in whole second.
As a further preferable scheme of the pseudo-range measurement method of the mixed constellation of the Beidou navigation satellite system, in the step 4, the subframe head is corrected to the position of the whole second in a soft computing mode, so that pseudo-range synchronous output of all satellites is realized.
As a further preferable scheme of the pseudo-range measurement method of the mixed constellation of the Beidou navigation satellite system, in the step 4, under the premise of not changing the pseudo-range latch signal period, a software correction method is adopted to realize pseudo-range synchronous output of three types of Beidou satellites, namely, two rates of navigation messages.
As a further preferable scheme of the pseudo-range measurement method of the Beidou navigation satellite system mixed constellation, in step 5, the pseudo-range propagation time of one IGSO closest to the equator is selected as a reference, and the pseudo-range propagation time of the GEO is corrected.
As a further preferable scheme of the pseudo-range measurement method of the mixed constellation of the Beidou navigation satellite system, in step 7, the GEO pseudo-range propagation time is corrected by adopting a fuzzy control method.
As a further preferable scheme of the pseudo-range measurement method of the hybrid constellation of the Beidou navigation satellite system, in step 9, the pseudo-range propagation time of the GEO satellite and the IGSO satellite is corrected by adopting a simplified fuzzy control rule.
Compared with the prior art, the invention has the beneficial effects that:
the method is characterized in that the traditional pseudo range latch signal is not changed, pseudo range propagation time output by a channel is corrected on a software level, and pseudo range synchronous output and receiver positioning under three satellites and two navigation message modes of the Beidou are realized by using the fuzzy control idea and utilizing the characteristics that the orbit heights of an IGSO satellite and a GEO satellite are the same and the difference of the pseudo range transmission time is not large. The invention has the advantages of clear purpose, simple technology, easy realization and strong engineering application value, is suitable for the Beidou navigation receiver, and has reference value for other satellite navigation systems adopting mixed constellations or different navigation messages.
Drawings
FIG. 1 is a flow chart of the functional implementation of the present invention;
FIG. 2 is a block diagram of the fuzzy control principle of the present invention;
FIG. 3 is a fuzzy control input membership function curve according to the present invention;
FIG. 4 is a fuzzy control output membership function curve according to the present invention;
FIG. 5 shows the time when tρ,GEO>tρ,IGSO_rThen, positioning a front subframe header and a pseudo range to latch a signal position schematic diagram;
FIG. 6 shows the time when tρ,GEO＝tρ,IGSO_rThen, positioning a front subframe header and a pseudo range to latch a signal position schematic diagram;
FIG. 7 shows the time when tρ,GEO<tρ,IGSO_rThen, positioning a front subframe header and a pseudo range to latch a signal position schematic diagram;
FIG. 8 is a schematic diagram of the positions of the positioned subframe header, pseudo-range latch signal, and IGSO frame synchronization second-order signal;
fig. 9 is a schematic diagram of positions of the positioned subframe header, pseudo-range latch signal, and IGSO frame synchronization second signal when a frame decoding failure occurs.
Detailed Description
The technical scheme of the invention is explained in detail in the following with the accompanying drawings:
as shown in fig. 1, a pseudo-range measurement method for a hybrid constellation of a beidou navigation satellite system specifically includes the following steps:
step 1, powering on and resetting a receiver, and randomly generating a pseudo-range latch signal TIC with adjustable rising edge position in the receiver;
step 2, generating a local ranging code and a carrier, capturing a satellite signal, and enabling the successfully captured signal to enter a tracking channel;
step 3, respectively carrying out bit synchronization and subframe synchronization on the GEO satellite, the IGSO satellite and the MEO satellite;
step 4, after sub-frame synchronization of each channel is realized, switching to a pseudo-range output and ephemeris demodulation mode, and further calculating initial pseudo-range propagation time, satellite position and pseudo-range correction parameters, wherein after the IGSO satellite and MEO satellite channels realize bit synchronization, frame synchronization second-integer pulse signals are triggered, and pseudo-range output at the Beidou second-integer position is realized;
step 4.1, after the IGSO satellite and the MEO satellite channel realize sub-frame synchronization, triggering a frame synchronization whole second pulse signal, wherein the period of the frame synchronization whole second pulse signal is 1s, the rising edge lags behind the first 1ms of the sub-frame, so that the position of the frame synchronization whole second pulse is convenient to update when the next sub-frame arrives, and the frame synchronization whole second pulse has the function of realizing pseudo-range output with the frequency of 1 Hz;
4.2, after the sub-frame synchronization of each channel is realized, switching to a pseudo-range output and ephemeris demodulation mode, detecting that a sub-frame head or frame synchronization whole second pulse triggers a high-power code clock counter to count and latch, wherein the frequency of the counter is that the counter at the frame starting moment is cleared, the counting is carried out until the moment of the TIC rising edge, and the value of the counter is synchronously placed in the latch;
step 4.3, each channel reads the frame synchronization count value and calculates the pseudo-range propagation time of the channel, wherein the calculation formula is tρ＝1-Nc/fc；
Step 5, selecting the pseudo-range propagation time of the IGSO satellite calculated in the step 4 as a reference tρ,IGSO_rPseudo-range transmission time t for GEO satellitesρ,GEOCorrecting;
step 6: correcting pseudo-range propagation time of the GEO satellite channel by adopting a fuzzy control rule to obtain pseudo-range propagation time t synchronous with IGSOρ,GEO_cor；
Step 7, obtaining an initial pseudo range rho according to the pseudo range propagation time, and smoothing the pseudo range by adopting a carrier phase:
where ρ iss,kFor the smoothed pseudorange, phi, at the current timekIs the carrier phase, p, at the current times,k-1Smoothed by the last time instant of the pseudorange, phik-1Is the carrier phase, p, of the previous time instantkThe pseudo range which is not smoothed at the current moment is M, and the time constant is smoothed;
and 8, calculating the clock error of the receiver by positioning the receiver, further calculating the control quantity of the pseudo-range latch signal, and further correcting the position of the pseudo-range latch signal, wherein the specific calculation formula is as follows:
NTIC,k＝NTIC,k-1+(Δu-ΔtTIC_frame)*fc/c
in the above formula,. DELTA.uClock error residual, Δ t, obtained for receiver positioningTIC_frameFixed delay for channel frame synchronization, NTIC,kIs the control quantity of TIC at the present moment, NTIC,k-1Control quantity of TIC at the previous time, fcSampling frequency for TIC;
and 9, after the receiver realizes primary positioning, correcting the TIC pulse to be aligned with the Beidou in whole second.
In step 4, the period of one sub-frame of the GEO is 0.6 seconds, and the sub-frame head is corrected to the position of the whole second in a soft computing mode to solve the problem that the sub-frame cannot be aligned with the whole second of the Beidou, so that pseudo-range synchronous output of all satellites is achieved.
Under the premise of not changing the pseudo range latch signal period, the method of software correction is adopted to realize pseudo range synchronous output of three types of Beidou satellites, namely under two-rate navigation messages.
And selecting the pseudo-range propagation time of the IGSO closest to the equator as a reference by utilizing the characteristic that the IGSO satellite and the GEO satellite are at the same orbit height, and correcting the pseudo-range propagation time of the GEO.
Before positioning, the pseudo range latch signal TIC, the position of the GEO satellite sub-frame header and the position of the IGSO satellite sub-frame header are different, and the GEO pseudo range propagation time is corrected by adopting a fuzzy control method.
And aiming at the condition that the pseudo-range propagation time of the GEO satellite and the IGSO satellite is only three possible conditions after the receiver realizes positioning, the simplified fuzzy control rule is adopted for correction.
The overall flow chart of the method is shown in fig. 2, and the Beidou intermediate frequency signals are respectively processed. The above process requires the following work to be done:
1. the Beidou navigation receiver realizes the technical scheme and needs to have a baseband signal processing function and a loop tracking and positioning resolving function. The baseband signal processing function comprises carrier NCO generation, code NCO generation, complex phase rotary digital down conversion, local Beidou spread spectrum code generation, a correlator, time base signal generation, observation data measurement, frame synchronization signal generation, navigation message demodulation and the like. The loop tracking and positioning resolving functions mainly complete the functions of prediction of Beidou visible satellites, Doppler prediction, initialization of each channel of the Beidou, reading and storage of an advance, instant and lag correlation value of each channel, loop control of a carrier tracking loop and a code tracking loop, reading of pseudo-range latching moment observation data, carrier phase assisted pseudo-range smoothing processing, tracking Doppler filtering processing, reading of subframe data and navigation message analysis, real-time storage of satellite ephemeris and almanac, Beidou positioning resolving and speed solving, Beidou time service loop control, framing and framing of a serial port protocol and the like.
2. A fuzzy controller is constructed.
And constructing a one-dimensional fuzzy control rule. Setting the difference delta t between the pseudo range propagation time of the GEO latched by the pseudo range latch signal and the reference IGSO satelliteρ,GEO-IGSO_rThe fuzzy subset of the control quantity (i.e. correction quantity) U is { NX, NB, NM, NS, ZO, P }, respectively represents negative, positive, middle, negative, zero, positive, the discrete domain is { -0.8, -0.6, -0.4, -0.2, 0, 0.6}, the output is a discrete precise value, the fuzzy identification rule is 'IfAthen B', and the fuzzy relation R can be written as R A × B
Written as a fuzzy inference sentence:
ifE＝N thenU＝P
ifE＝ZO thenU＝ZO
ifE＝PS thenU＝NS
ifE＝PM thenU＝NM
ifE＝PB thenU＝NB
ifE＝PX thenU＝NX
the input and output membership function curves are shown in fig. 3 and 4, respectively.
For the correction of the GEO pseudo range transmission time by the fuzzy control rule, the three conditions that the GEO pseudo range transmission time is greater than, equal to or less than the reference IGSO pseudo range transmission time are discussed according to two modes before and after the positioning of the receiver, and the main difference of the two modes before and after the positioning is that whether the pseudo range latch signal TIC is aligned with the whole second of the Beidou. It should be noted that all the following fuzzy control rules do not contradict each other, and the set of fuzzy control rules applies to all cases.
2.1 before the receiver is positioned, the position of the TIC rising edge is random, and the GEO pseudo range transmission time is larger than the reference IGSO. As shown in fig. 5, there are three cases as shown in table 1:
TABLE 1
| Situation(s) | (a) | (b) | (c) |
| E | ZO | PB | N |
| U | ZO | NB | P |
In the figure, a transverse arrow is time flow, a longitudinal arrow is the relative position of a subframe header and the rising edge of a pseudo-range latch signal, the highest dotted arrow is the pseudo-range latch signal, the period is 1s, the k-1 moment is before, and the k moment is after, the difference between the two is 1 s; the higher solid arrow is an IGSO sub-frame header, the period is 6s, the lowest solid arrow is a GEO sub-frame header, and the period is 0.6 s; n is a radical ofc1And Nc2And pseudo range count values of the IGSO satellite and the GEO satellite respectively latched by the pseudo range latch signals.
In case (a), two subframe headers latched by pseudo-range latching signals are synchronous subframe headers, the input quantity is suitable for a fuzzy rule ZO, the output quantity is suitable for ZO, and t is not required to be latchedρ,GEOCorrecting; the latched GEO subframe header is one GEO subframe period ahead of the IGSO subframe header under the condition (b), the input quantity is suitable for the fuzzy rule PB, and the output quantity is suitable for NB, tρ,GEOSubtracting 6 s; case (c) the latched IGSO subframe header precedes the GEO subframe header by one GEO subframe period, the input quantity applies the fuzzy rule N, the output quantity applies P, tρ,GEOAnd adding 6 s.
2.2 before the receiver is positioned, the position of the TIC rising edge is random, and the GEO pseudo range transmission time is exactly equal to the reference IGSO. As shown in fig. 6, there are two cases as shown in table 2:
TABLE 2
| Situation(s) | (a) | (b) |
| E | ZO | PB |
| U | ZO | NB |
In case (a), two subframe headers latched by pseudo-range latching signals are synchronous subframe headers, the input quantity is suitable for a fuzzy rule ZO, the output quantity is suitable for ZO, and t is not required to be latchedρ,GEOCorrecting; the latched GEO subframe header is one GEO subframe period ahead of the IGSO subframe header under the condition (b), the input quantity is suitable for the fuzzy rule PB, and the output quantity is suitable for NB, tρ,GEOMinus 6 s.
2.3 before the receiver is positioned, the position of the TIC rising edge is random, and the GEO pseudo range transmission time is less than the reference IGSO. As shown in fig. 7, there are two cases as shown in table 3:
TABLE 3
| Situation(s) | (a) | (b) |
| E | ZO | PB |
| U | ZO | NB |
In case (a), two subframe headers latched by pseudo-range latching signals are synchronous subframe headers, the input quantity is suitable for a fuzzy rule ZO, the output quantity is suitable for ZO, and t is not required to be latchedρ,GEOCorrecting; the latched GEO subframe header is one GEO subframe period ahead of the IGSO subframe header under the condition (b), the input quantity is suitable for the fuzzy rule PB, and the output quantity is suitable for NB, tρ,GEOMinus 6 s.
2.4 after the receiver is positioned, the TIC position is corrected by clock error, and the position of the rising edge is aligned with the whole second of the Beidou. As shown in fig. 8: and triggering the IGSO frame synchronous whole second pulse, and basically fixing the positions of the pseudo-range latch signal, the IGSO subframe head, the GEO subframe head and the IGSO frame synchronous whole second pulse.
TABLE 4
| E | PM | PB | PX |
| U | NM | NB | NX |
As shown in Table 4, latched GEO subframe header and IGSThe O sub-frame head has only three position relations, the GEO sub-frame head is advanced than the IGSO sub-frame head, the advanced quantity (namely input quantity) is suitable for the fuzzy control rules PM, PB and PX, the output quantity is correspondingly suitable for NM, NB and NX, tρ,GEOThe corresponding subtraction was 0.4s, 0.6s, 0.8 s. The shorter vertical dotted line in the figure is the IGSO frame synchronization whole second signal, the period is 1s, 1ms later than the IGSO subframe.
2.5 before and after the receiver is positioned, weak signals and strong interference cause possible failure of the GEO satellite in frame decoding. As shown in fig. 9, if the frame decoding of the two sub-frame headers shown in the figure fails, the pseudorange latch signal actually latches the pseudorange count value of the previous GEO sub-frame header, and the pseudorange latch signal can be corrected by using the fuzzy control rule, so as to output the correct pseudorange, and improve the robustness of the receiver, as shown in table 5:
TABLE 5
| E | ZO | PS |
| U | ZO | NS |
3. The least square method realizes receiver positioning and clock error correction.
And positioning the receiver by using a least square method to obtain a clock error, and returning a clock error parameter to correct the TIC so that the TIC is aligned with the Beidou satellite time (BDT) in whole second. The algorithm is as follows:
the equation of pseudorange is
ρcj＝[(xj-xu)2+(yj-yu)2+(zj-zu)2]1/2+tu+vj(1)
Where ρ iscjIs the pseudorange of satellite j to the user, (x)u，yu，zu) And (x)j，yj，zj) Respectively representing the position coordinates, t, of the user and the satellite in the ECEF coordinate systemuEquivalent distance error, v, for user clock errorjThe number of observed satellites is n for the corrected pseudorange error. And writing the receiver position and the clock deviation into two parts of a receiver position coordinate, a receiver clock deviation and a correction quantity.
Wherein,for the receiver position coordinates and receiver clock error, Δ xu，Δyu，Δzu，ΔtuIs the corresponding correction amount.
For pseudo-range observation equation inAnd performing Taylor series expansion, and neglecting high-order terms to obtain:
the constant term of the localization equation is:
the receiver to satellite j observation vector is:
wherein R isjIs the distance of satellite j to the receiver position, the pseudorange residuals may be expressed as:
in the above formula, there are 4 unknowns Δ xu、Δyu、Δzu、ΔtuThe distance measurement can be carried out by using 4 satellites to solve the distance measurement, because the receiver position is used in the equation, an iterative method is required to be adopted for calculation, the receiver position can be randomly selected, the iteration frequency is smaller when the calculated receiver position is close to the real position, and the calculated delta x is calculated twice continuouslyu、Δyu、Δzu、tuThe value difference is very small, the iteration can be stopped, pjThe pseudoranges are corrected through a series of corrections for the actual measured pseudoranges.
Writing the above formula in a matrix form includes:
Δρ＝H*Δx (7)
wherein:
when the number of the satellites participating in the calculation is as large as 4, the calculation can be performed by using a least square method, and the calculation result is as follows:
Δx＝(HTH)-1HTΔρ (8)
the foregoing is only a preferred embodiment of this invention and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the invention and these modifications should also be considered as the protection scope of the invention.
Claims (5)
1. A pseudo-range measurement method for a mixed constellation of a Beidou navigation satellite system is characterized by comprising the following steps: the method specifically comprises the following steps:
step 1, powering on and resetting a receiver, and randomly generating a pseudo-range latch signal TIC with adjustable rising edge position in the receiver;
step 2, generating a local ranging code and a carrier, capturing a satellite signal, and enabling the successfully captured signal to enter a tracking channel;
step 3, respectively carrying out bit synchronization and subframe synchronization on the GEO satellite, the IGSO satellite and the MEO satellite;
step 4, after sub-frame synchronization of each channel is realized, switching to a pseudo-range output and ephemeris demodulation mode, and further calculating initial pseudo-range propagation time, satellite position and pseudo-range correction parameters, wherein after the IGSO satellite and MEO satellite channels realize bit synchronization, frame synchronization second-integer pulse signals are triggered, and pseudo-range output at the Beidou second-integer position is realized;
step 5, selecting the pseudo-range propagation time of the IGSO satellite calculated in the step 4 as a reference tρ,IGSO_rPseudo-range transmission time t for GEO satellitesρ,GEOCorrecting;
step 6: correcting pseudo-range propagation time of the GEO satellite channel by adopting a fuzzy control rule to obtain pseudo-range propagation time t synchronous with IGSOρ,GEO_cor；
Step 7, obtaining an initial pseudo range rho according to the pseudo range propagation time, and smoothing the pseudo range by adopting a carrier phase:
<mrow> <msub> <mi>&rho;</mi> <mrow> <mi>s</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo>=</mo> <mfrac> <mn>1</mn> <mi>M</mi> </mfrac> <msub> <mi>&rho;</mi> <mi>k</mi> </msub> <mo>+</mo> <mfrac> <mrow> <mi>M</mi> <mo>-</mo> <mn>1</mn> </mrow> <mi>M</mi> </mfrac> <mo>&lsqb;</mo> <msub> <mi>&rho;</mi> <mrow> <mi>s</mi> <mo>,</mo> <mi>k</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mo>+</mo> <mi>&lambda;</mi> <mrow> <mo>(</mo> <msub> <mi>&phi;</mi> <mi>k</mi> </msub> <mo>-</mo> <msub> <mi>&phi;</mi> <mrow> <mi>k</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mo>)</mo> </mrow> <mo>&rsqb;</mo> </mrow>
where ρ iss,kFor the smoothed pseudorange, phi, at the current timekIs the carrier phase, p, at the current times,k-1Smoothed by the last time instant of the pseudorange, phik-1Is the carrier phase, p, of the previous time instantkThe pseudo range which is not smoothed at the current moment is M, and the time constant is smoothed;
and 8, calculating the clock error of the receiver by positioning the receiver, calculating the control quantity of the pseudo-range latch signal, and further correcting the position of the pseudo-range latch signal, wherein the specific calculation formula is as follows:
NTIC,k＝NTIC,k-1+(Δu-ΔtTIC_frame)*fc/c
<mrow> <msub> <mi>N</mi> <mrow> <mi>T</mi> <mi>I</mi> <mi>C</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo>=</mo> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>N</mi> <mrow> <mi>T</mi> <mi>I</mi> <mi>C</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo>+</mo> <msub> <mi>f</mi> <mi>c</mi> </msub> </mrow> </mtd> <mtd> <mrow> <msub> <mi>N</mi> <mrow> <mi>T</mi> <mi>I</mi> <mi>C</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo><</mo> <mn>0</mn> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>N</mi> <mrow> <mi>T</mi> <mi>I</mi> <mi>C</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>f</mi> <mi>c</mi> </msub> </mrow> </mtd> <mtd> <mrow> <msub> <mi>N</mi> <mrow> <mi>T</mi> <mi>I</mi> <mi>C</mi> <mo>,</mo> <mi>k</mi> </mrow> </msub> <mo>></mo> <msub> <mi>f</mi> <mi>c</mi> </msub> </mrow> </mtd> </mtr> </mtable> </mfenced> </mrow>
in the above formula,. DELTA.uClock error residual, Δ t, obtained for receiver positioningTIC_frameFixed delay for channel frame synchronization, NTIC,kIs the control quantity of TIC at the present moment, NTIC,k-1Control quantity of TIC at the previous time, fcSampling frequency for TIC;
and 9, after the receiver realizes primary positioning, correcting the TIC pulse to be aligned with the Beidou in whole second.
2. The pseudorange measurement method for a beidou navigation satellite system hybrid constellation according to claim 1, characterized in that: in step 4, the subframe head is corrected to the position of the whole second in a soft computing mode, so that pseudo range synchronous output of all satellites is achieved.
3. The pseudorange measurement method for a beidou navigation satellite system hybrid constellation according to claim 1, characterized in that: in step 4, under the premise of not changing the pseudo range latch signal period, the synchronous output of the pseudo ranges of the Beidou three types of satellites, namely the two-rate navigation message, is realized by adopting a software correction method.
4. The Beidou navigation satellite system mixed constellation pseudorange measurement method of claim 1, characterized in that: in step 5, the pseudorange propagation time of an IGSO closest to the equator is selected as a reference, and the pseudorange propagation time of the GEO is corrected.
5. The Beidou navigation satellite system mixed constellation pseudorange measurement method of claim 1, characterized in that: in step 9, the pseudorange propagation times of the GEO satellite and the IGSO satellite are corrected using a simplified fuzzy control rule.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510854630.XA CN105445765B (en) | 2015-11-30 | 2015-11-30 | A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510854630.XA CN105445765B (en) | 2015-11-30 | 2015-11-30 | A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105445765A CN105445765A (en) | 2016-03-30 |
| CN105445765B true CN105445765B (en) | 2017-10-31 |
Family
ID=55556178
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510854630.XA Expired - Fee Related CN105445765B (en) | 2015-11-30 | 2015-11-30 | A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105445765B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108008424B (en) * | 2017-11-27 | 2021-04-02 | 上海航天测控通信研究所 | Method and device for generating pulse per second of satellite navigation receiver |
| CN108089431B (en) * | 2018-01-24 | 2019-11-08 | 桂林电子科技大学 | A kind of adaptive satellite navigation time service method and device |
| CN109541652A (en) * | 2018-11-12 | 2019-03-29 | 北京时代民芯科技有限公司 | A kind of Beidou, GPS dual-mode vehicle-mounted terminal system |
| CN111123331B (en) * | 2019-10-23 | 2023-07-25 | 湖北三江航天险峰电子信息有限公司 | Beidou navigation pseudo-range monitoring method and system |
| CN111208543B (en) * | 2020-03-08 | 2022-05-10 | 湖南跨线桥航天科技有限公司 | Quick positioning method and system by utilizing GEO satellite of BDS (brain-based data service) system |
| CN113093250B (en) * | 2021-06-04 | 2021-08-27 | 腾讯科技（深圳）有限公司 | Pseudo-range observation data restoration method, positioning information determination method and device |
| CN113595615B (en) * | 2021-07-26 | 2022-07-12 | 中国科学院国家空间科学中心 | Method and system for realizing multi-satellite communication ranging |
| CN113866801B (en) * | 2021-08-31 | 2024-05-28 | 郑州威科姆华大北斗导航科技有限公司 | Beidou satellite positioning accuracy evaluation improvement method and system based on vertical projection |
| CN114839649B (en) * | 2022-04-11 | 2024-06-04 | 南京航空航天大学 | Distributed time service multi-point positioning receiver |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091687A (en) * | 2013-01-08 | 2013-05-08 | 南京航空航天大学 | Big dipper receiver multi-satellite signal joint capturing method |
| CN103901444A (en) * | 2014-03-20 | 2014-07-02 | 南京航空航天大学 | Beidou satellite navigation receiver bit synchronization method |
| CN104483688A (en) * | 2014-11-03 | 2015-04-01 | 中国人民解放军63961部队 | High precision baseline solution method based on Beidou satellite navigation system |
| CN104570017A (en) * | 2015-01-08 | 2015-04-29 | 南京航空航天大学 | Avoiding and stripping method for Neumann-Hoffman codes in navigation messages of Beidou navigation satellite system D1 |
| CN104865587A (en) * | 2015-06-15 | 2015-08-26 | 中国人民解放军国防科学技术大学 | Quick locating method based on GEO constellation coarse location for Beidou receiver |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8866671B2 (en) * | 2009-11-04 | 2014-10-21 | Qualcomm Incorporated | Methods and apparatuses using mixed navigation system constellation sources for time setting |
-
2015
- 2015-11-30 CN CN201510854630.XA patent/CN105445765B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091687A (en) * | 2013-01-08 | 2013-05-08 | 南京航空航天大学 | Big dipper receiver multi-satellite signal joint capturing method |
| CN103901444A (en) * | 2014-03-20 | 2014-07-02 | 南京航空航天大学 | Beidou satellite navigation receiver bit synchronization method |
| CN104483688A (en) * | 2014-11-03 | 2015-04-01 | 中国人民解放军63961部队 | High precision baseline solution method based on Beidou satellite navigation system |
| CN104570017A (en) * | 2015-01-08 | 2015-04-29 | 南京航空航天大学 | Avoiding and stripping method for Neumann-Hoffman codes in navigation messages of Beidou navigation satellite system D1 |
| CN104865587A (en) * | 2015-06-15 | 2015-08-26 | 中国人民解放军国防科学技术大学 | Quick locating method based on GEO constellation coarse location for Beidou receiver |
Non-Patent Citations (3)
| Title |
|---|
| 刘建业 等.基于伪距差分的三星无源北斗/SINS组合导航系统.《中国惯性技术学报》.2007,第15卷(第4期), * |
| 林雪原 等.一种基于伪距的RDSS/SINS组合导航系统.《上海交通大学学报》.2004,第38卷(第10期), * |
| 林雪原 等.北斗双星定位系统改进及其算法的研究.《空间科学学报》.2003,第23卷(第2期), * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105445765A (en) | 2016-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105445765B (en) | A kind of pseudo range measurement method of Beidou navigation satellite system hybrid constellation | |
| US11726213B2 (en) | Fast and precise positioning method and system | |
| CN103344978B (en) | Area enhanced precision positioning service method suitable for large-scale users | |
| Sun et al. | Research and progress of Beidou satellite navigation system | |
| CN109901206B (en) | Single-star positioning and time service method based on low-orbit satellite radio range signal | |
| WO2006073490A2 (en) | Generating high precision ionospheric ground-truth measurements | |
| CN105842720B (en) | A kind of wide area precision real-time location method based on carrier phase | |
| Kassas et al. | Ad astra: Simultaneous tracking and navigation with megaconstellation LEO satellites | |
| CN103760572A (en) | Single-frequency PPP ionosphere weighting method based on region CORS | |
| CN104570024A (en) | Beidou space-based high-precision real-time positioning method | |
| DE10054764A1 (en) | Mobile radio hand set location determination for the cellular infrastructure, involves detecting location of mobile radio hand set in response to GPS ephemeris data, clock and differential correction data and updated ephemeris data | |
| CN104049262A (en) | Beam forming anti-interference method based on vector tracking loop | |
| CN107861131A (en) | The acquisition methods and system of a kind of wrong path footpath ionosphere delay | |
| CN107607971A (en) | Temporal frequency transmission method and receiver based on GNSS common-view time alignment algorithms | |
| Choy et al. | GPS precise point positioning with the Japanese Quasi-Zenith Satellite System LEX augmentation corrections | |
| CN106093967A (en) | The ionosphere delay method for solving that a kind of pseudorange phase place is comprehensive | |
| Mallika et al. | A new ionospheric model for single frequency GNSS user applications using Klobuchar model driven by auto regressive moving average (SAKARMA) method over Indian region | |
| WO2021082189A1 (en) | Precise orbit and ground station data-based beidou satellite maneuvering and anomaly detection method | |
| Yuan et al. | The ionospheric eclipse factor method (IEFM) and its application to determining the ionospheric delay for GPS | |
| Paziewski et al. | Enhanced wide-area multi-GNSS RTK and rapid static positioning in the presence of ionospheric disturbances | |
| CN115951378B (en) | Self-adaptive information fusion positioning method based on Beidou satellite-based enhanced information | |
| CN113406677A (en) | Navigation signal broadcasting method and device and navigation signal receiving method | |
| Lou et al. | The impact of non-nominal yaw attitudes of GPS satellites on kinematic PPP solutions and their mitigation strategies | |
| CN106125117A (en) | A kind of inertia/satellite hypercompact combination local signal controlled quentity controlled variable generates method | |
| CN105717524B (en) | A kind of Beidou navigation satellite system receiver pseudo range measurement improved method based on FPGA and DSP |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20160330 Assignee: JIANGSU BDSTAR NAVIGATION AUTOMOTIVE ELECTRONICS CO.,LTD. Assignor: Nanjing University of Aeronautics and Astronautics Contract record no.: 2018320000067 Denomination of invention: Pseudo range measuring method for hybrid constellation of Beidou Navigation Satellite System Granted publication date: 20171031 License type: Exclusive License Record date: 20180320 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20171031 Termination date: 20211130 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |