JP4322829B2 - Cycle slip detection device and cycle slip detection method - Google Patents

Description

  The present invention relates to a cycle slip detection apparatus and a cycle slip detection method for detecting a cycle slip occurring in a global positioning system (GPS).

GPS consists of a plurality of satellites and receivers that receive data from these satellites. By mounting this receiver on a moving body such as a vehicle, ship, or aircraft, the position, speed, etc. can be measured accurately. (For example, refer nonpatent literature 1).
Geodetic Society of Japan "Newly revised version of GPS-precise positioning system using artificial satellites"

However, the GPS has the following problems to be solved.
In order for a receiver to receive data from an artificial satellite and perform positioning, it is necessary to receive a carrier wave emitted from the artificial satellite and thereby keep track of the position of the artificial satellite from which the data is transmitted.

  Usually, the uncertainty in tracking satellites is constant, but for example, if there is a shield such as a tree or a building between the receiver and the satellite, reception of the carrier wave is interrupted, When reception is resumed, the above uncertainty value changes. Such a phenomenon is called cycle slip, and is an obstacle to accurate positioning.

  The cycle slip value is about 19 cm for the L1 signal (frequency: 1575.42 Mhz, wavelength: about 19 cm).

  The artificial satellite orbits the orbit at an altitude of about 20000 km, and the change in the distance between the artificial satellite and the receiver is larger than the cycle slip value, and signal noise, multipath, etc. Due to the influence, it is difficult to detect a phase change of about 19 cm from the carrier phase itself observed by the receiver.

  As a method for detecting the cycle slip, there is a method in which phase data of two artificial satellites are collected twice at different times and a triple difference is taken. However, this method cannot identify which of the two artificial satellites is causing the cycle slip.

  In view of such circumstances, the present invention provides a cycle slip detection device and a cycle slip detection method capable of efficiently and reliably performing cycle slip detection and identification of an artificial satellite in which cycle slip has occurred. With the goal.

  The present invention according to claim 1 is a cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, and a pseudorange in the past of the artificial satellite to be observed. Is approximated by a least-squares equation, thereby estimating a pseudorange at a future time, estimating a carrier phase acceleration at a future time based on the pseudorange, and calculating an average value of the carrier phase acceleration within a predetermined time range. First calculation means for calculating and calculating the difference between the measured value and the average value of the carrier phase acceleration at the time, and minimizing the pseudorange in the past of an artificial satellite different from the artificial satellite to be observed by an nth-order equation Approximate the square, thereby estimating the pseudorange at the future time, and based on the pseudorange, the carrier phase acceleration at the future time A second computing means for estimating and calculating an average value of the carrier phase acceleration within a predetermined time range, and obtaining a difference between the measured value and the average value of the carrier phase acceleration at the time, and the first computing means. A third computing means for obtaining a difference difference between artificial satellites, which is a difference between a difference in the observed artificial satellite and a difference in another artificial satellite obtained by the second computing means; A first comparison unit that compares a predetermined threshold value, and compares a difference between each of the observation target artificial satellite and another artificial satellite when the difference difference between the artificial satellites is larger than the threshold value and the predetermined threshold value; When the difference between the second comparison means and the observation target artificial satellite is greater than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target artificial satellite, and another artificial Difference in the star is summarized in that and a and determination means cycle slip occurs in said another satellite in the case of larger than a predetermined threshold value.

  The present invention according to claim 2 is a cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, and is information relating to the orbit of the artificial satellite to be observed. The distance to the satellite is calculated based on a certain ephemeris, the carrier phase acceleration at a future time is estimated based on the distance, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the carrier phase acceleration at the time is calculated. A distance to the artificial satellite is calculated based on the first computing means for obtaining the difference between the actual measurement value and the average value, and an ephemeris of an artificial satellite different from the observation target artificial satellite, and at a future time based on the distance. The carrier phase acceleration is estimated, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the carrier time acceleration is calculated. A second calculating means for obtaining a difference between the measured value and the average value of the phase acceleration, a difference in the artificial satellite to be observed obtained by the first computing means, and another obtained by the second computing means A third calculating means for obtaining an inter-satellite difference difference which is a difference from the difference in the artificial satellite; a first comparing means for comparing the inter-satellite difference difference with a predetermined threshold; and the inter-satellite difference difference is a threshold value. A second comparison means for comparing a difference between a satellite to be observed and another artificial satellite and a predetermined threshold when the difference is greater than the predetermined threshold. Is determined that a cycle slip has occurred in the satellite to be observed, and if the difference in another satellite is greater than a predetermined threshold, the cycle slip has occurred in the other satellite. And summarized in that and a has a determination means form.

  The present invention according to claim 3 is a cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, and a pseudo-range in the past of the observation target artificial satellite. Is approximated by a least-squares equation, thereby estimating a pseudorange at a future time, estimating a carrier phase acceleration at a future time based on the pseudorange, and calculating an average value of the carrier phase acceleration within a predetermined time range. A first comparison means for calculating and calculating a difference between the measured value and the average value of the carrier phase acceleration at the time and comparing the difference with a predetermined threshold; and an artificial object to be observed when the difference is greater than the threshold Estimate the pseudorange at the future time by approximating the pseudorange in the past of an artificial satellite different from the satellite by the least squares equation using the nth order equation. The carrier phase acceleration at the future time is estimated based on the pseudorange, the average value of the carrier phase acceleration within a predetermined time range is calculated, the difference between the measured value and the average value of the carrier phase acceleration at the time is obtained, and the difference And a predetermined threshold value and a determination means for determining that a cycle slip has occurred when the difference obtained by the second comparison means is equal to or less than the threshold value. And

  The present invention according to claim 4 is a cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, and is based on an ephemeris of an artificial satellite to be observed. Calculate the distance to the artificial satellite, estimate the carrier phase acceleration at the future time based on the distance, calculate the average value of the carrier phase acceleration within the predetermined time range, and measure the actual value and average value of the carrier phase acceleration at the time Based on an ephemeris of an artificial satellite different from the artificial satellite to be observed when the difference is greater than the threshold, To estimate the carrier phase acceleration at the future time based on the distance, and within the predetermined time range of the carrier phase acceleration. An average value is calculated, a difference between the measured value and the average value of the carrier phase acceleration at the time is obtained, and a second comparison unit that compares the difference with a predetermined threshold value and a difference obtained by the second comparison unit are The gist of the present invention is to have a determination unit that determines that a cycle slip has occurred when the value is equal to or less than the threshold value.

  The present invention according to claim 5 is a cycle slip detection method for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, wherein the pseudo distance in the past of the artificial satellite to be observed is measured. Is approximated by a least-squares equation, thereby estimating a pseudorange at a future time, estimating a carrier phase acceleration at a future time based on the pseudorange, and calculating an average value of the carrier phase acceleration within a predetermined time range. A first calculation step for calculating and calculating the difference between the actual measurement value and the average value of the carrier phase acceleration at the time, and minimizing the pseudorange in the past of an artificial satellite different from the artificial satellite to be observed by an nth-order equation Approximate the square, thereby estimating the pseudorange at the future time, and based on the pseudorange, the carrier phase acceleration at the future time And calculating the average value of the carrier phase acceleration within a predetermined time range to obtain the difference between the measured value and the average value of the carrier phase acceleration at the time, and the first calculation step. A third computation step for obtaining an inter-satellite difference difference, which is a difference between the difference in the observed satellite and the difference in another satellite obtained in the second computation step; A first comparison step for comparing a predetermined threshold value and a difference between the difference between the artificial satellite to be observed and another artificial satellite when the difference difference between the artificial satellites is larger than the threshold value and the predetermined threshold value When the difference between the second comparison step and the observation target satellite is greater than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target satellite. Differences in Engineering satellites summarized as having a a determination step of determining the cycle slip occurs in said another satellite in the case of larger than a predetermined threshold value.

  The present invention according to claim 6 is a cycle slip detection method for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, and is information relating to the orbit of an artificial satellite to be observed. The distance to the satellite is calculated based on a certain ephemeris, the carrier phase acceleration at a future time is estimated based on the distance, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the carrier phase acceleration at the time is calculated. A distance to the artificial satellite is calculated based on a first calculation step for obtaining a difference between the actual measurement value and the average value, and an ephemeris of an artificial satellite different from the observation target artificial satellite, and at a future time based on the distance. The carrier phase acceleration is estimated, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the carrier time acceleration is calculated. A second calculation step for obtaining the difference between the measured value and the average value of the phase acceleration, the difference in the artificial satellite to be observed obtained in the first calculation step, and another difference obtained in the second calculation step A third calculation step for obtaining an inter-satellite difference difference that is a difference from the difference in the artificial satellite, a first comparison step for comparing the inter-satellite difference difference with a predetermined threshold, and the inter-satellite difference difference is a threshold value. A second comparison step of comparing the difference between the observation target satellite and another artificial satellite with a predetermined threshold when the difference is greater than the predetermined threshold. If it is determined that a cycle slip has occurred in the observation target satellite, and the difference in the other satellite is greater than a predetermined threshold, the cycle slip in the other satellite is greater. There is summarized in that and a determining step to be occurring.

  The present invention according to claim 7 is a cycle slip detection method for detecting a cycle slip that occurs in a global positioning system including a plurality of artificial satellites, the pseudo-range in the past of the artificial satellite to be observed. Is approximated by a least-squares equation, thereby estimating a pseudorange at a future time, estimating a carrier phase acceleration at a future time based on the pseudorange, and calculating an average value of the carrier phase acceleration within a predetermined time range. A first comparison step of calculating and calculating a difference between an actual measurement value and an average value of carrier phase acceleration at a time, and comparing the difference with a predetermined threshold value, and an artificial object to be observed when the difference is larger than the threshold value Estimate the pseudorange at the future time by approximating the pseudorange in the past of an artificial satellite different from the satellite by the least squares equation using the nth order equation. The carrier phase acceleration at the future time is estimated based on the pseudorange, the average value of the carrier phase acceleration within a predetermined time range is calculated, the difference between the measured value and the average value of the carrier phase acceleration at the time is obtained, and the difference And a predetermined comparison threshold, and a determination step that determines that a cycle slip has occurred when the difference obtained in the second comparison step is equal to or less than the threshold. And

  The present invention according to claim 8 is a cycle slip detection method for detecting a cycle slip generated in a global positioning system including a plurality of artificial satellites, based on an ephemeris of an artificial satellite to be observed. Calculate the distance to the artificial satellite, estimate the carrier phase acceleration at the future time based on the distance, calculate the average value of the carrier phase acceleration within the predetermined time range, and measure the actual value and average value of the carrier phase acceleration at the time A first comparison step for obtaining a difference between the second difference and a predetermined threshold value, and an artificial satellite based on an ephemeris of an artificial satellite different from the observation target artificial satellite when the difference is larger than the threshold value To estimate the carrier phase acceleration at the future time based on the distance, and within the predetermined time range of the carrier phase acceleration. The average value is calculated, the difference between the measured value and the average value of the carrier phase acceleration at the time is obtained, and the difference obtained in the second comparison step is compared with the second comparison step for comparing the difference with a predetermined threshold value. A gist of determining that a cycle slip has occurred when the value is equal to or less than the threshold.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform the detection of a cycle slip and the identification of the artificial satellite which has generated the cycle slip efficiently and reliably.

Hereinafter, the cycle slip detection device and the cycle slip detection method of the present invention will be described with reference to the drawings.
The following examples are only for the purpose of explaining the present invention and do not limit the scope of the present invention. Accordingly, those skilled in the art can employ various embodiments including each or all of these elements, and these embodiments are also included in the scope of the present invention.
In all the drawings for explaining the following embodiments, the same reference numerals are given to the same elements, and the repeated explanation thereof is omitted.

FIG. 1 is a configuration diagram of a GPS (global positioning system) 1 according to a first embodiment (embodiment 1) of the present invention.
This GPS 1 includes a plurality of artificial satellites 2 (in the figure, five of 2a to 2d are shown) and a cycle slip detection device 4 that receives data 3 (3a to 3d) transmitted from the artificial satellite 2. Become.

  The cycle slip detection device 4 receives pseudorange information, carrier phase information, and the like from the artificial satellite 2 and detects a cycle slip based on these information. The antenna slip 5, the receiving unit 6, and the storage unit 7, a calculation unit 8, a determination unit 9, and an input / output unit 10.

  The receiving unit 6 receives the above various information from the artificial satellite 2 via the antenna unit 5.

  The calculation unit 8 calculates a numerical value that serves as a determination material for determining whether or not a cycle slip has occurred based on the information received by the reception unit 6.

Perform arithmetic processing.

  The storage unit 7 stores threshold values and the like necessary for determination by the determination unit 9.

  The determination unit 9 determines whether a cycle slip has occurred based on the calculation result of the calculation unit 8.

  Details of the formulas stored in the storage unit 7 and the processing of the calculation units 8 and 9 will be described later.

  The input / output unit 10 receives an input signal (processing start instruction signal or the like) by the user, and outputs a calculation result or a determination result to the user.

Next, the principle of cycle slip detection by the cycle slip detection device 4 will be described.
The pseudo distance R ^s _i and the carrier phase φ ^s _i are expressed by the following equations.

In the above equation, R _i ^s is the pseudorange [m] of the artificial satellite s (eg, 2a) observed at the observation point i, and φ _i ^s is the carrier phase [cycle] observed at the observation point i (λ Ρ _i ^s is the true distance (geometric distance) between the artificial satellite s and the cycle slip detector 4, and N _i ^s is an integer uncertain value (ambient). Dep _i ^s is the ephemeris error, dt _i is the clock offset of the cycle slip detector 4, dt ^s is the clock offset of the satellite s, and dtrp _i ^s is the tropospheric delay of the satellite s observed at the observation point i. [m], dion _i ^s is the ionospheric delay [m] of satellite s observed at observation point i, dM _i ^s is the multipath [cycle] of satellite s observed at observation point i, and ε _ρ is the code range An error [m] such as noise and ε _φ indicate an error [cycle] such as carrier phase noise.

  If the data collection time interval is about 1 second, changes in tropospheric delay and ionospheric delay can be ignored.

  Further, in the cycle slip detection device 4 of the present invention, the “pseudo-range least square method” and the “ephemeris-based method” are used to detect the cycle slip. Details of these will be described below.

“Method 1: When using pseudorange least squares”
A value obtained by approximating the pseudo distance by the least square method is expressed by the following equation.

  Further, when the above equation (3) is converted into cycle units and subtracted from the equation (2), the following equation is obtained.

  Note that the left side δ () of the equation (4) indicates an error (model error) between the value approximated by the least square method and the true value.

Further, the difference (velocity) between adjacent data in the equation (4) is zero if there is no cycle slip as shown in the equation (5 ′), and the integer uncertain value does not change. When a cycle slip occurs between two collected samples, the integer uncertainty value changes. If the integer change value at this time is n ^s ₁ , the following equation (5) is obtained.

  Here, “•” in each character represents speed. The speed of the distance ρ to the artificial satellite 2 is about ± 1 km / s.

  In this case, since the distance ρ approximated by the least square approximation of the quadratic equation of the pseudorange is subtracted, the speed of the distance ρ becomes slower than the original speed.

Further, since the satellite 2 is equipped with an atomic clock, the satellite time changes by about 10 ⁻¹¹ to 10 ⁻¹² s / s, and changes from 0.03 to 0.0003 m / s in 1 second. Furthermore, the acceleration change of the atomic clock is zero.

On the other hand, since the internal clock provided in the receiving unit 6 of the cycle slip detection device 4 changes about 10 ⁻⁶ s / s, it changes at 3 km / s per second. The internal clock also includes an acceleration component. In this case, the value approximated by the second least square approximation of the pseudorange is also subtracted, so that the amount of change is smaller than the original amount.

  Regarding the multipath speed change, the movement of the artificial satellite 2 seen from the observation point is slow, and it takes several minutes or more for the elevation angle to change once, and the amount of change per second is It can be ignored.

  For this reason, the geometric relationship between the satellite, the reflector, and the cycle slip detection device 4 can be regarded as having no change in one second, and since the geometric relationship does not change, the multipath velocity component is zero. Can be considered.

  In any case, since the carrier phase speed has a change of the internal clock and the like, there is a possibility of taking a value of ± several hundreds m / s, so it is difficult to find an integer value change.

  For this reason, in the present invention, in order to clarify the change in the integer value, the difference (acceleration) of the carrier phase velocity is obtained as shown in the following equation.

  Note that k in the above equation indicates the order of data collection.

  As shown in the equation (6), when a cycle slip occurs, an integer value change appears. The acceleration component of the satellite time can be regarded as zero because an atomic clock is used.

The acceleration of the satellite distance does not exceed 0.019 / s ² (GPS Standard Positioning Service performance, 2001), and the noise on the cycle slip detector side is 1 cm / s ² or less (eg 0.0075 m / s). s ² ).

On the other hand, the acceleration of the clock of the cycle slip detection device 4 varies depending on the clock used (TCXO, OCXO, Rb, Cs). When Rb or Cs is used, the clock acceleration can be regarded as zero. When using TCXO, the acceleration changes at about 1 × 10 ^-6 m / s ² . In 1 minute, it becomes a change of 0.0006m / s ² and can be regarded as almost constant. Since OCXO has better temperature characteristics and short-term stability than TCXO, it can be considered constant for 1 minute.

From the above, when the acceleration average value for the past several minutes (example 1 minute) is subtracted from the equations (6) and (6 ′), the following results. The average for the past several minutes is represented by [aφ] ₁ .

  When cycle slip has occurred, a change of an integral multiple appears as shown in the equation (7). However, at this time, there is a possibility that the internal clock of the cycle slip detection device fluctuates greatly, or that the clock noise is determined as a cycle slip. In order to prevent this, by taking a difference from an artificial satellite u (for example, 2b) different from the artificial satellite s, whether the above result is due to clock noise or a unique cycle generated in the artificial satellite s. It is possible to determine whether it is a slip phenomenon.

  At this time, the same result can be obtained even if the subtraction between the artificial satellites is performed at the stage of the above formula (2) or (4).

  Whether or not a cycle slip has occurred is determined using a certain threshold value (eg, 0.75), and if it is greater than this threshold value, it is determined that a cycle slip has occurred.

  In this case, the following equation (8) is used.

  When it is determined that a cycle slip has occurred by using this equation, the value of equation (7) corresponding to the artificial satellite s and the artificial satellite u is checked to determine which cycle slip has occurred.

  Further, when a cycle slip occurs, tracking on the cycle slip detection device 4 side may be interrupted, and data 3 may not be output periodically, and the collection time interval of carrier phase data is larger than the set time interval value. Is also large, it is determined that a cycle slip has occurred.

“Method 2: When using ephemeris-based satellite positions and precise surveying station positions”
In this method, we calculate the satellite position Xs and precision surveying observation point position X ₀ from the ephemeris. In addition, when the distance is expressed by these values, the following formula is obtained.

  Further, when the above equation (9) is converted into cycle units and subtracted from the equation (2), the following equation is obtained.

The difference (velocity) between the proximity data of the above equation (10) is zero because the integer uncertain value does not change unless the cycle slip occurs. For example, when a cycle slip occurs between two collected samples, the integer uncertainty value changes. If the integer change value at this time is n ^s ₁ , the following equation (11) is obtained.

Here, “•” in each character represents speed. Since the satellite 2 is equipped with an atomic clock, the satellite time changes from about 10 ⁻¹¹ to 10 ⁻¹² s / s and changes from 0.03 to 0.0003 m / s per second. Furthermore, the acceleration change of the atomic clock is zero.

On the other hand, since the internal clock of the cycle slip detection device changes about 10 ⁻⁶ s / s, it changes at 3 km / s per second. The internal clock also includes an acceleration component. In this case, the value approximated by the second least square approximation of the pseudorange is also subtracted, so that the amount of change is smaller than the original amount.

  Regarding the multipath speed change, the movement of the artificial satellite 2 seen from the observation point is slow, and it takes several minutes or more for the elevation angle to change once, and the amount of change per second is It can be ignored.

  For this reason, the geometric relationship between the satellite, the reflector, and the cycle slip detection device 4 can be regarded as having no change in one second, and since the geometric relationship does not change, the multipath velocity component is zero. Can be considered.

  In any case, since the carrier phase speed has a change of the internal clock and the like, there is a possibility of taking a value of ± several hundreds m / s, so it is difficult to find an integer value change.

  For this reason, in the present invention, in order to clarify the change in the integer value, the difference (acceleration) of the carrier phase velocity is obtained as shown in the following equation.

  Note that k in the above equation indicates the order of data collection.

  As shown in the equation (6), when a cycle slip occurs, an integer value change appears. The acceleration component of the satellite time can be regarded as zero because an atomic clock is used.

The acceleration of the satellite distance does not exceed 0.019 / s ² (GPS Standard Positioning Service performance, 2001), and the noise on the cycle slip detector side is 1 cm / s ² or less (eg 0.0075 m / s). s ² ).

On the other hand, the acceleration of the clock of the cycle slip detection device 4 varies depending on the clock used (TCXO, OCXO, Rb, Cs). When Rb or Cs is used, the clock acceleration can be regarded as zero. When using TCXO, the acceleration changes at about 1 × 10 ^-6 m / s ² . In 1 minute, it becomes a change of 0.0006m / s ² and can be regarded as almost constant. Since OCXO has better temperature characteristics and short-term stability than TCXO, it can be considered constant for 1 minute.

From the above, when the acceleration average value for the past several minutes (example 1 minute) is subtracted from the equations (12) and (12 ′), the following results. The average for the past several minutes is represented by [aφ] ₁ .

  When cycle slip has occurred, a change of an integral multiple appears as shown in the equation (13). However, at this time, there is a possibility that the internal clock of the cycle slip detection device fluctuates greatly, or that the clock noise is determined as a cycle slip. In order to prevent this, by taking a difference from an artificial satellite u (for example, 2b) different from the artificial satellite s, whether the above result is due to clock noise or a unique cycle generated in the artificial satellite s. It is possible to determine whether it is a slip phenomenon.

  At this time, the same result can be obtained even if the subtraction between the artificial satellites is performed at the stage of the above formula (2) or (4).

  Whether or not a cycle slip has occurred is determined using a certain threshold value (eg, 0.75), and if it is greater than this threshold value, it is determined that a cycle slip has occurred.

  In this case, the following equation (14) is used.

  When it is determined that a cycle slip has occurred by using this equation, the value of equation (14) corresponding to the artificial satellite s and the artificial satellite u is checked to determine which cycle slip has occurred.

  Further, when a cycle slip occurs, tracking on the cycle slip detection device 4 side may be interrupted, and data 3 may not be output periodically, and the collection time interval of carrier phase data is larger than the set time interval value. Is also large, it is determined that a cycle slip has occurred.

  The pseudo distance, ephemeris, and the like are periodically output by the receiving unit 6 at a predetermined time interval, and the observation time is recorded at the same time.

Next, details of the cycle slip detection process by the cycle slip detection device 4 will be described with reference to FIG.
As described above, when there is a shield or the like between the artificial satellite 2a and the antenna unit 5, the receiving unit 6 may not be able to periodically receive data transmitted from the artificial satellite 2a.

  Accordingly, the calculation unit 8 obtains a difference (observation interval) between the latest observation time of the carrier phase of the artificial satellite to be observed (for example, 2a) and the previous observation time (most recent observation time), and the determination unit 9 Reads a predetermined time interval value from the storage unit 7 and compares it with the observation interval (S11). If the observation interval is greater than the predetermined time interval value (S11: YES), cycle slip Is determined to occur (S20a).

  On the other hand, when the observation interval is not larger than the predetermined time interval value (S11: NO), the calculation unit 8 displays the pseudorange of the artificial satellite 2a output by the reception unit 6 (for the past several observations, in this embodiment). (3 times) is calculated by a least square approximation curve by an nth order equation (secondary equation in this embodiment) (S12), thereby estimating a pseudorange at the next observation time (future time) of the artificial satellite 2a ( S13) Based on this, the carrier phase velocity and acceleration at the future time are estimated (S14).

  Further, the acceleration of the artificial satellite 2a is always calculated, and when the calculation unit 8 calculates the estimated value of the acceleration, the calculation unit 8 calculates an average value of this value and the acceleration in a past fixed period (S15).

  The acceleration at the future time is estimated, and when the time comes, the calculation unit 8 calculates the difference between the measured value (observed value) of the carrier phase acceleration and the above average value (S16).

  Next, the calculation unit 8 performs the same processing as S12 to S16 on other artificial satellites (for example, 2b), and calculates the difference between the measured value and the average value of the carrier phase acceleration in the artificial satellite 2b ( S17), the determination unit 9 calculates a difference between the difference in the artificial satellite 2a and the difference in the artificial satellite 2b (in the following description, this is referred to as “difference difference between artificial satellites”) (S17). Then, the predetermined threshold value is read from the storage unit 7 and this threshold value and the difference difference between the artificial satellites are compared (S18). If the difference difference between the artificial satellites is not larger than the threshold value (S18: NO), It is determined that this is due to the displacement of the internal clock, and it is determined that no cycle slip has occurred (S20b).

  On the other hand, when the difference difference between the artificial satellites is larger than the threshold (S18: YES), the difference (observed value and average value of the carrier phase acceleration) in each of the artificial satellites 2a (S artificial satellite) and 2b (U artificial satellite). ) And the threshold (S19), and if the difference of the artificial satellite 2a is larger than the threshold (S19: S artificial satellite), it is determined that a cycle slip has occurred in the artificial satellite 2a, When the difference of the artificial satellite 2b is larger than the threshold (S19: U artificial satellite), it is determined that a cycle slip has occurred in the artificial satellite 2b. As described above, in this embodiment, it is possible to reliably identify the artificial satellite in which the cycle slip has occurred.

FIG. 3 is a diagram illustrating the processing operation of the cycle slip detection device 4 according to the second embodiment (second embodiment) of the present invention.
In the first embodiment (FIG. 1), the case where the average acceleration value is calculated based on the pseudo distance has been shown. However, as described above, the ephemeris can also be used. The details will be described below.

  If the observation interval is larger than the time interval value in S21, the calculation unit 8 reads the mathematical expression from the storage unit 7, calculates the position of the artificial satellite 2a based on the ephemeris of the artificial satellite 2a (S22), The distance between the position of the artificial satellite and the observation point (the position of the cycle slip detection device 4) is calculated (S24).

  Next, the carrier phase velocity and acceleration at the next observation time (future time) of the artificial satellite 2a are estimated based on the distance (S24).

  Note that the subsequent processing from S25 to S30 is the same as the processing from S15 to S20 in the first embodiment, and thus the description thereof is omitted.

FIG. 4 is a diagram showing the processing operation of the cycle slip detection device 4 according to the third example (Example 3) of the present invention.
In the first embodiment (FIG. 2), after calculating the difference between the acceleration average values, the difference between the satellites is calculated, and based on this, it is determined whether or not cycle slip has occurred. However, in this embodiment, the determination is performed based on the difference between the carrier phase angle and the average acceleration value. The details will be described below. In addition, since the process from S41 to S46 of this figure (FIG. 4) is the same as the process from S11 to S16 of Example 1, description is abbreviate | omitted.

  When the difference between the measured value of the carrier phase acceleration and the average acceleration value is calculated in S46, the determination unit 9 reads a predetermined threshold value from the storage unit 7, and compares this threshold value with the difference (S47). When the difference is not greater than the threshold value (S47: NO), it is determined that the cycle slip has not been determined (S59b).

  On the other hand, when the above difference is larger than the threshold, the same processing as S42 to S46 is performed for other artificial satellites (for example, 2b), and the determination unit 9 determines the difference between the carrier phase difference in the other artificial satellites and the aforementioned If the difference is not greater than the threshold (S48: NO), it is determined that this is due to the displacement of the internal clock of the receiver 6, and it is determined that no cycle slip has occurred (S48: NO). S49b).

  On the other hand, when the difference is larger than the threshold (S48: YES), it is determined that a cycle slip has occurred (S6a).

FIG. 5 is a diagram showing the processing operation of the cycle slip detection device 4 according to the fourth example (Example 4) of the present invention.
In the above-described embodiment 3 (FIG. 4), the acceleration average value is calculated based on the pseudo distance and the determination is performed based on the difference between the carrier phase angle and the acceleration average value. As shown in FIG. 5 (FIG. 5), the present invention can also be applied to the case where the average acceleration value is calculated based on the ephemeris.

  The processing from S51 to S56 in this figure is the same as the processing from S21 to S26 in the second embodiment (FIG. 3), and the processing from S57 to S59 is the processing from S47 to S49 in the third embodiment. Since it is the same as that of FIG.

  As described above, according to the present invention, a cycle slip of a minimum of about 19 cm can be efficiently and reliably detected without using a method such as taking a triple difference, and precise survey using a carrier phase is continuously performed. It becomes possible.

  Further, by detecting the cycle slip, it is possible to eliminate and correct data that is adversely affected by the cycle slip, and it is possible to improve the reliability and accuracy of positioning.

  Note that a cycle slip detection method using the cycle slip detection apparatus as described above is also included in the scope of the present invention.

It is a figure which shows the structure of the global positioning system which concerns on Example 1 of this invention. It is a figure which shows the processing operation of the cycle slip detection apparatus of FIG. It is a figure which shows the processing operation of the cycle slip detection apparatus which concerns on Example 2 of this invention. It is a figure which shows the processing operation of the cycle slip detection apparatus which concerns on Example 3 of this invention. It is a figure which shows the processing operation of the cycle slip detection apparatus which concerns on Example 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Global positioning system, 2 ... Artificial satellite, 3 ... Data, 4 ... Cycle slip detection apparatus, 5 ... Antenna part, 6 ... Reception part, 7 ... Memory | storage part, 8 ... Calculation part, 9 ... Determination part, 10 ... Input / output section

Claims (8)

A cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of satellites,
The pseudo-range in the past of the artificial satellite to be observed is approximated by a least-squares equation using an nth-order equation, thereby estimating the pseudo-range at the future time, and estimating the carrier phase acceleration at the future time based on the pseudo-range, A first calculation means for calculating an average value of the carrier phase acceleration within a predetermined time range, and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A pseudo-range in the past of an artificial satellite different from the observation target artificial satellite is approximated by a least-squares equation by an nth-order equation, thereby estimating a pseudo-range at a future time, and based on the pseudo-distance at the future time A second computing means for estimating a carrier phase acceleration, calculating an average value of the carrier phase acceleration within a predetermined time range, and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A first inter-satellite difference difference, which is a difference between the difference in the observation target artificial satellite obtained by the first arithmetic means and the difference in the second artificial satellite obtained by the second arithmetic means. 3 computing means;
First comparison means for comparing the difference between the satellites with a predetermined threshold;
A second comparison means for comparing a difference between each of the artificial satellite to be observed and the other artificial satellite and a predetermined threshold when the difference between the artificial satellites is larger than the threshold;
When the difference in the observation target artificial satellite is larger than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target artificial satellite, and the difference in the other artificial satellite is larger than the predetermined threshold. A cycle slip detection device, comprising: a determination unit that determines that a cycle slip has occurred in the other artificial satellite when the size is larger. A cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of satellites,
A distance to the satellite is calculated based on the ephemeris that is information on the orbit of the artificial satellite to be observed, a carrier phase acceleration at a future time is estimated based on the distance, and a predetermined time range of the carrier phase acceleration A first calculation means for calculating a difference between the measured value of the carrier phase acceleration at the time and the average value;
A distance to the artificial satellite is calculated based on an ephemeris of an artificial satellite different from the observation target artificial satellite, a carrier phase acceleration at a future time is estimated based on the distance, and a predetermined carrier phase acceleration is determined. A second calculating means for calculating an average value within a time range and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A first inter-satellite difference difference, which is a difference between the difference in the observation target artificial satellite obtained by the first arithmetic means and the difference in the second artificial satellite obtained by the second arithmetic means. 3 computing means;
First comparison means for comparing the difference between the satellites with a predetermined threshold;
A second comparing means for comparing a difference between each of the artificial satellite to be observed and the other artificial satellite and a predetermined threshold when the difference between the artificial satellites is larger than the threshold;
When the difference in the observation target artificial satellite is larger than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target artificial satellite, and the difference in the other artificial satellite is larger than the predetermined threshold. A cycle slip detection device, comprising: a determination unit that determines that a cycle slip has occurred in the other artificial satellite when the size is larger. A cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of satellites,
The pseudo-range in the past of the artificial satellite to be observed is approximated by a least-squares equation using an nth-order equation, thereby estimating the pseudo-range at the future time, and estimating the carrier phase acceleration at the future time based on the pseudo-range, A first comparison for calculating an average value of the carrier phase acceleration within a predetermined time range, obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold value Means,
When the difference is larger than the threshold value, the pseudo distance in the past of an artificial satellite different from the observation target artificial satellite is approximated by the least-squares equation by an nth order equation, thereby estimating the pseudo distance at a future time, The carrier phase acceleration at the future time is estimated based on the pseudo distance, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the difference between the measured value of the carrier phase acceleration at the time and the average value And a second comparison means for comparing the difference with a predetermined threshold;
A cycle slip detection apparatus comprising: a determination unit that determines that a cycle slip has occurred when a difference obtained by the second comparison unit is equal to or less than the threshold value. A cycle slip detection device for detecting a cycle slip generated in a global positioning system including a plurality of satellites,
The distance to the satellite is calculated based on the ephemeris of the satellite to be observed, the carrier phase acceleration at a future time is estimated based on the distance, and the average value of the carrier phase acceleration within a predetermined time range is calculated. Calculating, calculating a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold;
When the difference is larger than the threshold value, the distance to the satellite is calculated based on the ephemeris of the satellite different from the observation target satellite, and the carrier phase acceleration at the future time is calculated based on the distance. Estimating, calculating an average value of the carrier phase acceleration within a predetermined time range, obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold value. Two comparison means;
A cycle slip detection apparatus comprising: a determination unit that determines that a cycle slip has occurred when a difference obtained by the second comparison unit is equal to or less than the threshold value. A cycle slip detection method for detecting a cycle slip occurring in a global positioning system including a plurality of satellites,
The pseudo-range in the past of the artificial satellite to be observed is approximated by a least-squares equation using an nth-order equation, thereby estimating the pseudo-range at the future time, and estimating the carrier phase acceleration at the future time based on the pseudo-range, A first calculation step of calculating an average value of the carrier phase acceleration within a predetermined time range, and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A pseudo-range in the past of an artificial satellite different from the observation target artificial satellite is approximated by a least-squares equation by an nth-order equation, thereby estimating a pseudo-range at a future time, and based on the pseudo-distance at the future time A second calculation step of estimating the carrier phase acceleration, calculating an average value of the carrier phase acceleration within a predetermined time range, and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A first inter-satellite difference difference that is a difference between the difference in the observation target artificial satellite obtained in the first calculation step and the difference in the second artificial satellite obtained in the second calculation step is obtained. 3 calculation steps;
A first comparison step of comparing the difference between the satellites with a predetermined threshold;
A second comparison step of comparing a difference between each of the artificial satellite to be observed and the other artificial satellite and a predetermined threshold when the difference between the artificial satellites is greater than the threshold;
When the difference in the observation target artificial satellite is larger than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target artificial satellite, and the difference in the other artificial satellite is larger than the predetermined threshold. A cycle slip detection method for determining that a cycle slip has occurred in the other artificial satellite when it is large. A cycle slip detection method for detecting a cycle slip occurring in a global positioning system including a plurality of satellites,
A distance to the satellite is calculated based on the ephemeris that is information on the orbit of the artificial satellite to be observed, a carrier phase acceleration at a future time is estimated based on the distance, and a predetermined time range of the carrier phase acceleration A first calculation step for calculating a difference between the measured value of the carrier phase acceleration at the time and the average value;
A distance to the artificial satellite is calculated based on an ephemeris of an artificial satellite different from the observation target artificial satellite, a carrier phase acceleration at a future time is estimated based on the distance, and a predetermined carrier phase acceleration is determined. A second calculation step of calculating an average value within a time range and obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value;
A first inter-satellite difference difference that is a difference between the difference in the observation target artificial satellite obtained in the first calculation step and the difference in the second artificial satellite obtained in the second calculation step is obtained. 3 calculation steps;
A first comparison step of comparing the difference between the satellites with a predetermined threshold;
A second comparison step of comparing a difference between each of the artificial satellite to be observed and the other artificial satellite and a predetermined threshold when the difference between the artificial satellites is greater than the threshold;
When the difference in the observation target artificial satellite is larger than a predetermined threshold, it is determined that a cycle slip has occurred in the observation target artificial satellite, and the difference in the other artificial satellite is larger than the predetermined threshold. A cycle slip detection method for determining that a cycle slip has occurred in the other artificial satellite when it is large. A cycle slip detection method for detecting a cycle slip occurring in a global positioning system including a plurality of satellites,
The pseudo-range in the past of the artificial satellite to be observed is approximated by a least-squares equation using an nth-order equation, thereby estimating the pseudo-range at the future time, and estimating the carrier phase acceleration at the future time based on the pseudo-range, A first comparison for calculating an average value of the carrier phase acceleration within a predetermined time range, obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold value Process,
When the difference is larger than the threshold value, the pseudo distance in the past of an artificial satellite different from the observation target artificial satellite is approximated by the least-squares equation by an nth order equation, thereby estimating the pseudo distance at a future time, The carrier phase acceleration at the future time is estimated based on the pseudo distance, the average value of the carrier phase acceleration within a predetermined time range is calculated, and the difference between the measured value of the carrier phase acceleration at the time and the average value And a second comparison step for comparing the difference with a predetermined threshold value;
And a determination step of determining that a cycle slip has occurred when the difference obtained in the second comparison step is equal to or less than the threshold value. A cycle slip detection method for detecting a cycle slip occurring in a global positioning system including a plurality of satellites,
The distance to the satellite is calculated based on the ephemeris of the satellite to be observed, the carrier phase acceleration at a future time is estimated based on the distance, and the average value of the carrier phase acceleration within a predetermined time range is calculated. A first comparison step of calculating, obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold;
When the difference is larger than the threshold value, the distance to the satellite is calculated based on the ephemeris of the satellite different from the observation target satellite, and the carrier phase acceleration at the future time is calculated based on the distance. Estimating, calculating an average value of the carrier phase acceleration within a predetermined time range, obtaining a difference between the measured value of the carrier phase acceleration at the time and the average value, and comparing the difference with a predetermined threshold value. 2 comparison steps;
And a determination step of determining that a cycle slip has occurred when the difference obtained in the second comparison step is equal to or less than the threshold value.

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