JP2008249402A - Device and method for estimating inter-frequency bias - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately estimate an inter-frequency bias caused by a satellite and an inter-frequency bias caused by a receiver. <P>SOLUTION: The device includes: a total electron count calculation part for calculating a total electron count of the passage route of satellite signals based on a pseudo distance to each of a plurality of positioning satellites 10a, 10b, 10c from each of one or more receivers 24; a model value calculation part for calculating a total electron count model value based on an ionosphere electron density model function; a random number generation part for generating a random number; and an inter-frequency bias estimation part for calculating an inter-frequency bias based on the total electron count and the total electron count model value, determining temporarily a receiver-dependent inter-frequency bias and a satellite-dependent inter-frequency bias carried by the inter-frequency bias based on the random number, and estimating that the temporarily-determined receiver-dependent inter-frequency bias and satellite-dependent inter-frequency bias are true values when an error between position information based on a position surveyed beforehand and position information acquired by positioning the position is the smallest. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inter-frequency bias estimation apparatus and an inter-frequency bias estimation method for estimating the total number of ionospheric electrons in a passing path using a plurality of different frequency signals broadcast from a satellite.

  Signals transmitted from satellites such as the satellite navigation system “Galileo”, the GPS system, and the QZSS (Quasi-Zenith Satellite System) are used for positioning observation points on the earth. At that time, the radio wave propagation speed and the time required are important factors in obtaining the distance from the satellite whose position is known to the observation point. However, a radio wave signal transmitted from the satellite toward the ground causes a propagation delay when passing through the ionosphere, and greatly affects positioning errors. Therefore, accurately obtaining the ionospheric propagation delay is indispensable for performing highly accurate positioning.

  Conventionally, various methods have been proposed to accurately determine the ionospheric delay. For example, Patent Document 1 describes an inter-frequency bias calculation apparatus and method for calculating an inter-frequency bias necessary for calculating an accurate ionospheric delay amount. The inter-frequency bias is due to an electrical path difference between frequencies, and differs depending on hardware such as a receiver and a satellite. In order to calculate an accurate ionospheric delay, it is necessary to remove the inter-frequency bias.

  The inter-frequency bias calculation apparatus described in Patent Document 1 includes a first pseudo distance by a first frequency and a second pseudo distance by a second frequency from a GPS satellite to a plurality of GPS receivers. A data collection unit input from the plurality of GPS receivers, and a plurality of first and second pseudo distances input from the data collection unit are substituted into a predetermined arithmetic expression to obtain a frequency between the first and second frequencies. An inter-frequency bias calculation unit that calculates a bias, and a data output unit that outputs the inter-frequency bias calculated by the inter-frequency bias calculation unit to the GPS receiver. According to the inter-frequency bias calculation apparatus, the inter-frequency bias can be provided to the user with a simple configuration. Further, by performing a large amount of computation on the inter-frequency bias calculation device side, the burden on the GPS receiver side, that is, the user side can be reduced.

  The ionospheric propagation delay amount depends on the frequency of the propagated signal. Therefore, by receiving a plurality of frequency signals from the satellite, the total number of electrons (TEC: Total Electron Content) in the signal passing path can be obtained.

Non-Patent Document 1 and Non-Patent Document 2 describe an IRI (International Reference Ionosphere) model that is an electron density model function in the ionosphere. Further, Non-Patent Document 3 describes a Gallagher model that is also one of ionospheric electron density model functions. TEC can also be obtained by calculation using these model functions.
JP 2006-23144 A Dieter Bilitza, et, al. ,: “International Reference Ionsphere 1990”, November, 1990. Dieter Biritza: “International Reference Ionsphere 2000”, Radio. Science, Vol. 36, Number 2, PP261-275, March / April, 2001 Gallagher, D.C. L. , P.M. D. Craven, and R.M. H. Commfort, Global core plasma model, J. MoI. Geophys. Res. 105, A8, 18, 819-18, 833, 2000.

  However, the equation with the satellite bias and the receiver bias as unknowns is the same as the number of satellites for one observation point / observation time, whereas the unknown is the number of satellites + 1 (bias and Receiver bias), it is not possible to simply find a solution using simultaneous equations.

  However, when receiving a plurality of frequency signals from a satellite and obtaining the TEC in the signal passing path, a bias specific to the satellite / receiver is added, so it is necessary to obtain the bias of the satellite and the receiver. It is essential.

  Moreover, since the ionospheric electron density model function as described above has a monthly average level, there is an error from the observation result.

  The present invention solves the above-described problems of the prior art, and provides an inter-frequency bias estimation apparatus and an inter-frequency bias estimation method that accurately estimate the inter-frequency bias caused by the satellite and the inter-frequency bias caused by the receiver. The task is to do.

  In order to solve the above-described problem, an inter-frequency bias estimation apparatus according to the present invention has one or more receivers that receive satellite signals transmitted from a plurality of positioning satellites, and includes positioning information included in the satellite signals. An inter-frequency bias estimation apparatus that uses a positioning system to obtain position information using the total electron of the passage path of the satellite signal based on a pseudorange from each of the one or more receivers to each of the plurality of positioning satellites Calculated by a total electron number calculation unit for calculating a number, a model value calculation unit for calculating a total electron number model value based on an ionospheric electron density model function, a random number generation unit for generating random numbers, and the total electron number calculation unit The inter-frequency bias is calculated based on the total electron number and the total electron number model value calculated by the model value calculating unit, and the inter-frequency buffer is calculated based on the random number generated by the random number generating unit. A receiver-dependent inter-frequency bias and a satellite-dependent inter-frequency bias are determined temporarily, position information based on a pre-measured position, the receiver-dependent inter-frequency bias and the inter-satellite-dependent frequency bias When the error from the position information obtained by positioning the position based on the above is the smallest, the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are estimated to be true values. And an inter-frequency bias estimator.

  According to the present invention, since the inter-frequency bias caused by the satellite and the inter-frequency bias caused by the receiver are accurately estimated, the ionospheric total electron number estimation accuracy is improved, contributing to the improvement of the positioning accuracy and the ionospheric model. Can do.

  Embodiments of an inter-frequency bias estimation apparatus according to the present invention will be described below in detail with reference to the drawings.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an inter-frequency bias estimation apparatus 32 and a positioning system according to the first embodiment of the present invention. This inter-frequency bias estimation device 32 has one or more satellite signal receivers 24 that receive satellite signals transmitted from a plurality of positioning satellites (positioning satellites 10a, 10b, 10c), and includes positioning information included in the satellite signals. Use a positioning system that obtains location information using.

  First, the configuration of the present embodiment will be described. As shown in FIG. 1, the inter-frequency bias estimation apparatus 32 and the positioning system of the present embodiment include a positioning satellite 10a, a positioning satellite 10b, a positioning satellite 10c, a satellite signal processing system 20, an ionosphere TEC / bias estimation processing system 30, and An internet data processing system 40 is used. The positioning satellite 10a, the positioning satellite 10b, the positioning satellite 10c, and the satellite signal processing system 20 correspond to the positioning system of the present invention. Although a positioning system including the Internet data processing system 40 can be used, the Internet data processing system 40 is not necessarily essential and is additional. The satellite signal processing system 20, the ionosphere TEC / bias estimation processing system 30, and the Internet data processing system 40 are connected to each other via a communication line 50.

  The positioning satellite 10a, the positioning satellite 10b, and the positioning satellite 10c are navigation satellites such as GPS, Galileo, and Quasi-Zenith Satellite (QZSS), and transmit satellite signals having a plurality of frequencies.

  The satellite signal processing system 20 includes an antenna 22, a satellite signal receiver 24, and a satellite signal processing device 26. The satellite signal receiver 24 corresponds to the receiver of the present invention, and receives satellite signals of a plurality of frequencies transmitted from a plurality of positioning satellites (positioning satellites 10a, 10b, 10c) via the antenna 22. In addition, the satellite signal processing device 26 obtains position information using the positioning information included in the satellite signal.

  The ionosphere TEC / bias estimation processing system 30 includes an inter-frequency bias estimation device 32, and calculates the satellite position, the total number of ionosphere electrons (TEC) in the signal passing path, the inter-frequency bias, and the like based on the received signal. The received data and processing results are transmitted to the data server system via the LAN and stored.

  The internet data processing system 40 includes a router 42, a GEONET collection data processing device 44, and an external internet network 46. The router 42 may be a switching hub. The Internet data processing system 40 is the ionosphere-related information published, the GPS observation data (GEONET data) published by the Geospatial Information Authority of Japan, and the IGS (International GPS Service for Geodynamics) that is publishing international observation results. It is a device that collects data etc. via the Internet. The results collected by the internet data processing system 40 are processed by the ionosphere TEC / bias estimation processing system 30. The router 42 is provided in consideration of security and is a firewall.

  FIG. 2 is a detailed block diagram of the inter-frequency bias estimation apparatus 32 according to the first embodiment of the present invention. As shown in FIG. 2, the inter-frequency bias estimation device 32 includes a total electron number calculation unit 33, a model value calculation unit 34, an inter-frequency bias estimation unit 35, and a random number generation unit 36.

  The total electron number calculation unit 33 calculates the total number of electrons in the passage path of the satellite signal based on the pseudo distance from each of the one or more receivers to each of the plurality of positioning satellites. Specifically, the total number of electrons calculation unit 33 calculates the total number of electrons in the satellite signal passage path based on the pseudo distance from the satellite signal receiver 24 to each of the positioning satellites 10a, 10b, and 10c. The total electron number calculation unit 33 can also calculate the total number of electrons in the satellite signal passage path based on the data regarding the pseudo distance between the receiver and the satellite obtained from the external Internet network 46. A method for calculating the total number of electrons will be described later.

  The model value calculation unit 34 calculates the total electron number model value based on the ionosphere electron density model function such as the IRI model and Gallager model as described above.

  The random number generator 36 generates a random number.

  The inter-frequency bias estimation unit 35 calculates the inter-frequency bias based on the total electron number calculated by the total electron number calculation unit 33 and the total electron number model value calculated by the model value calculation unit 34, and the random number generation unit 36 Based on the generated random number, a receiver-dependent inter-frequency bias and a satellite-dependent inter-frequency bias that the inter-frequency bias has are tentatively determined. Further, the inter-frequency bias estimation unit 36 is obtained by measuring the position based on the position information based on the position measured in advance in advance, and the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias. When the error with the position information is the smallest, the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are estimated to be true values.

Next, the operation of the present embodiment configured as described above will be described. In addition, since the estimation becomes more complicated when it is a time zone in which the ionosphere changes dynamically, in this embodiment, the inter-frequency bias estimation device uses data measured at around 2:00 local time. To do. FIG. 3 is a flowchart showing the operation of the inter-frequency bias estimation apparatus 32 of this embodiment. First, the model value calculation unit 34 calculates the total electron number model value based on the ionosphere electron density model function (step S101). Here, if the ionospheric electron density model function is f, the total electron number model value of the passage path can be obtained by integrating the electron density of the passage path.

Equation (1) shows the result of integrating the ionospheric electron density function f along the path from the satellite Mg to the reception observation point R. Here, s is a parameter indicating the position. G is an identifier for identifying a satellite. TEC _g ^true indicates the true total number of electrons in the passage path. Δ _model indicates an error included in the ionosphere density distribution model.

  The model value calculation unit 34 outputs the calculated total electron number model value to the inter-frequency bias estimation unit 35.

Next, the total number of electrons calculator 33 calculates the total number of electrons in the satellite signal passage path based on the pseudoranges for each of the plurality of positioning satellites from each of the one or more receivers (step S103). Here, the pseudo distance between the positioning satellite 10a and the satellite signal receiver 24 is considered. The TEC of the satellite signal passing path is obtained based on satellite signals (indicated here by L1 and L2) transmitted from the positioning satellite 10a. First, the pseudo distance (code distance, pseudo range) and the phase distance (phase distance) can be expressed as follows.

Here, ρ represents a pseudo distance. Φ represents a phase distance. r indicates the true distance. c is the speed of light. Further, δt _u indicates a receiver time error, and δt ^s indicates a satellite time error. In this embodiment, the lower right subscript basically indicates a term related to the ground (receiver or the like), and the upper right subscript basically indicates a term related to the sky (satellite or the like). _{δtu, L1orL2 bias} indicates a receiver frequency dependent hardware dependent bias, and δt ^s _{L1orL2 bias} indicates a satellite frequency dependent hardware dependent bias. Further, I represents the ionospheric propagation delay amount, and T represents the tropospheric propagation delay amount. N _amb represents an integer uncertain value, and ε represents an observation error.

The total electron number calculator 33 can obtain the TEC by taking the difference between the observed values of the two frequencies.

Here, f is a frequency. Λ represents a wavelength. _Δbias indicates an inter-frequency bias. Δ ′ _bias is a bias with respect to the phase.

From the equation (4), the TEC is obtained as the following equation.

Here, TEC ^true indicates the true total number of electrons. The estimated value of TEC shown in equation (6) includes a term related to bias. Since the value of the error ε ′ is large as it is, the total electron number calculation unit 33 performs carrier smoothing to reduce the value of the error ε ′. Carrier smoothing is intended to reduce noise by applying a precise carrier wave difference to a pseudo-range containing a lot of noise. If the TEC after carrier smoothing is expressed as <TEC>, <TEC> is obtained by the following equation.

Here, m is a number assigned in order of data collection time. K is a smoothing constant and can be changed as appropriate. K also depends on the sampling time interval. For example, if the time constant is 180 seconds, K = 180 / dt. dt represents a sampling time interval. < _Δbias > is assumed to be constant for a period of about one month, and is assumed to be constant during the data collection period. Therefore, <Δ _bias > does not require the subscript m.

  The total electron number calculation unit 33 outputs the calculated total number of electrons to the inter-frequency bias estimation unit 35.

Next, the inter-frequency bias estimation unit 35 calculates the inter-frequency bias based on the total number of electrons calculated by the total number of electrons calculation unit 33 and the total number of electrons model value calculated by the model value calculation unit 34. First, the inter-frequency bias estimation unit 35 uses the total electron number obtained by the total electron number calculation unit 33 using the equation (8) based on the satellite observation data and the model value calculation unit 34 using the equation (1). A difference from the obtained total electron number model value is obtained (step S105).

Existing ionospheric electron density models, such as those used in equation (1), are in good agreement with observed values on a monthly average. Therefore _{, Δg, model in the} equation (9) becomes a value close to zero by averaging the data for one month. Furthermore, it is assumed that the inter-frequency bias of the satellite and the receiver has a small temporal variation, the time constant is considered to be about one month, and the data collected during this period is constant. If the average operation for one month is represented by [], the difference between the observed TEC and the model TEC shown in the equation (9) is as follows.

Here, dε represents a minute model error remaining after averaging. In this embodiment, it is assumed that dε is zero. It is considered that there is no correlation between the satellite dependent frequency bias and the receiver dependent frequency bias. Therefore, the difference between the observed TEC and the model TEC can be summarized into two independent terms as shown in equation (10). B ^g denotes the bias about the satellite g, _{B R} denotes a bias about the receiver. The receiver-dependent frequency bias and the bias of the satellite g are obtained by the equation (10). Therefore, if the receiver bias is determined, the bias of each satellite is determined.

Equation (10) can be equal to the number of satellites for one observation point / observation time. Here, when the number of satellites is N _sat , there are (N _sat +1) unknowns including the bias of the observation place receiver. Therefore, a solution cannot be obtained simply by simultaneous equations.

  Therefore, the inter-frequency bias estimation unit 35 temporarily determines a term related to the receiver of the equation (10) based on the random number generated by the random number generation unit 36 (step S107). Furthermore, since the inter-frequency bias estimation unit 35 tentatively determines the receiver-dependent inter-frequency bias, the bias component related to the satellite can be determined from equation (10).

Next, positioning is performed based on the determined bias value (step S109). The entity that performs positioning is a positioning system including a positioning satellite 10a, a positioning satellite 10b, a positioning satellite 10c, and a satellite signal processing system 20, and in particular, a satellite signal processing device 26. However, a configuration in which the inter-frequency bias estimation device 32 performs positioning may be employed. The true value of the positioning location and X _0. X ₀ is previously precisely survey. For this true value X _0, if the ΔX errors in positioning based on the determined bias value. ΔR, which is an error in the distance between the satellite and the receiver, can be expressed by the following equation.

Here, <ρ> in equation (13) indicates a pseudo distance after performing carrier smoothing as in equation (8). In the equation (11), r _R ^eph represents a geometric distance calculated from a precisely surveyed location X ₀ and the position of the satellite. This satellite position is GPS position data calculated from GPS position data or satellite broadcast ephemeris data provided by IGS. Also, T _est ^g indicates a tropospheric delay amount estimated value. In estimating the tropospheric delay amount, a tropospheric delay amount model is used. <I _{L1, est} ^g > indicates an ionospheric delay amount estimated value. Δt _{R, clock} indicates a clock offset of the receiver. The satellite clock offset (Δt ^{s, clock} ) is corrected by satellite broadcast ephemeris data. The ionospheric delay estimate _{<I L1, est} ^g> includes a bias. Since the bias generated in the receiver is common to each satellite, it has the same effect as the clock offset of the receiver and does not affect the positioning position error.

The relationship between the distance error ΔR and the positioning error ΔX shown in the equation (11) is shown as follows.

Here, A is a matrix and the direction vector elements from location X _0, which is precisely surveyed to the satellite. (L, m, n) represents a direction vector. The subscript indicates the satellite number. Therefore, in the equations (17) and (18), there are N satellites. Regarding the positioning position, ΔX is obtained by the least square method or the like. Equation (19) is a calculation example using the least square method. The fourth term of ΔX is related to the receiver clock offset. Since this term is related to the term in the second parenthesis of equation (11), the term in the second parenthesis of equation (11) is reflected and does not affect the positioning position. The first term in equation (11) affects the positioning position error. If the estimated value of the inter-satellite-dependent frequency bias is correct, the magnitude (error) of the first to third terms related to the position of ΔX becomes smaller.

By determining the term related to the receiver in the equation (10) by a random number, the bias value between the satellite dependent frequencies is temporarily determined. Here, assuming that the receiver-dependent frequency-bias bias determined by random numbers is _{BR , rand} , the satellite-dependent inter-frequency bias value B _cand ^g tentatively determined is obtained by the following equation.

Therefore, by substituting _{BR , rand} and B _cand ^g obtained by the equation (20) into the equation (11), the pseudorange error ΔR is as follows.

Here, when the satellite bias amount in the first parenthesis in the equation (21) is close to the true value, the magnitude of the positional error of ΔX is minimized. The position error Perr of ΔX can be expressed as follows from the Cartesian coordinate component of the position error, for example.

The inter-frequency bias estimation unit 35 determines a temporary receiver-dependent inter-frequency bias _{BR, rand} based on the random number generated by the random number generation unit 36. Every time this BR _{, rand} changes, the position error Perr in equation (22) changes. When Perr takes a minimum value, the inter-frequency bias estimation unit 35 estimates that the receiver-dependent inter-frequency bias BR _{, rand} at that time is a true value (step S111). Further, based on _{BR, rand} estimated to be a true value, the inter-satellite dependent frequency bias B _est ^g is calculated using equation (20) (step S113).

Obtaining an estimated value to the end with a random number is inefficient. Therefore, the inter-frequency bias estimation unit 35 obtains position information based on the position information based on the position measured in advance, and the position information obtained based on the provisionally determined receiver-dependent frequency bias and satellite-dependent frequency bias. Based on the rate of change of the error, the receiver-dependent frequency bias and the satellite-dependent frequency bias are estimated. Specifically, based on the random number generated by the random number generator 36, the inter-frequency bias estimator 35 generates a receiver-dependent inter-frequency bias k times ( _{BR, 1} , ..., _{BR, k} ). , Positioning position errors (Perr ₁ ,..., Perr _k ) are obtained. Further, the inter-frequency bias estimation unit 35 calculates a change rate of the positioning position error Perr with respect to a change rate of a term related to the receiver.

By (23), the change rate eta _k measured position error Perr for _{B R} is obtained. Based on this η _k , the receiver-dependent frequency-to-frequency bias _{BR, est} is obtained as follows.

First, when the signs of η _k are all positive or negative in the range of ( _{BR, 1} ,..., _{BR, k} ) _{, BR, est} is as follows.

The inter-frequency bias estimator 35 estimates _{BR, est} obtained by the equation (24) as a true receiver-dependent inter-frequency bias. When the bias value of the receiver is obtained in more detail, the inter-frequency bias estimation unit 35 again uses a random number related to the receiver in the vicinity of the _{BR, est} value obtained by the equation (24) ( B _{R, 1} ,..., B _{R, k} ) is calculated, and equation (23) is calculated.

Next, when the sign of η _k changes from minus to plus within the range of (BR _{, 1} ,..., BR _{, k} ), the minimum value of the position error Perr is around the sign change. Exists. Accordingly, assuming that BR _, k before and after the change of code is BR _{, k−, BR} , _{k +} , the estimated value _{BR, est} of the receiver-dependent frequency bias to be obtained is obtained as follows.

Here, η _{k +} and η _k− indicate the rate of change of BR _{, k +} having a plus sign and the rate of change of _{BR, k−} having a minus sign, respectively.

There is also a method of simply using an intermediate value as an estimated value. In that case, the estimated value _{BR, est} of the bias depending on the receiver frequency is obtained as follows.

When the estimated value _{BR, est} of the receiver-dependent frequency bias is obtained by the above-described method, the satellite-dependent frequency-bias bias _{BR, est} ^g of each satellite is expressed by the following equation (10). It is requested in this way.

The inter-frequency bias obtained as described above is an estimated value B _{R, est of} the receiver-dependent inter-frequency bias calculated in the specific receiver R and the satellite-dependent inter-frequency bias B _{R, est} ^g of each satellite. Therefore, this estimation result may include effects such as multipath effects due to the terrain of the observation point.

Therefore, in order to reduce the influence, the inter-frequency bias estimation unit 35, when the positioning system has a plurality of receivers (satellite signal processing system 20 in FIG. 1), position information obtained by each of the plurality of receivers. The satellite-dependent inter-frequency bias is estimated by averaging a plurality of satellite-dependent inter-frequency bias obtained for one positioning satellite. Specifically, the average value B _est ^g of the inter-satellite dependent frequency bias is obtained by the following equation.

  Here, W indicates the number of receivers that have performed processing. As described above, the inter-frequency bias estimation device 32 can obtain the inter-frequency bias (the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias). The operation described above can be applied to the inter-frequency bias estimation method.

  As described above, according to the inter-frequency bias estimation apparatus according to the first embodiment of the present invention, the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are determined based on random numbers. Can be estimated.

  In addition, the error between the position information based on the position measured precisely in advance, and the position information obtained by positioning the position based on the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias is the smallest. In this case, since it is estimated that the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias determined to be true values, the inter-frequency bias caused by the satellite and the inter-frequency bias caused by the receiver are accurately determined. Can be estimated.

  Furthermore, based on the accurately estimated receiver-dependent inter-frequency bias and satellite-dependent inter-frequency bias, the ionospheric total electron count estimation accuracy should be improved, contributing to the improvement of positioning accuracy and ionospheric models in GPS and other positioning systems. Can do. In addition, the accuracy of the ionosphere model used when calculating the propagation path of the frequency such as the HF band can be improved, and more effective communication can be enabled. It is also possible to improve navigation using satellites.

  The inter-frequency bias estimation apparatus according to the present invention can be used in a positioning system such as GPS that performs positioning using satellite signals transmitted from positioning satellites.

It is a block diagram which shows the structure of the bias estimation apparatus between frequency of the form of Example 1 of this invention, and a positioning system. 1 is a detailed block diagram of an inter-frequency bias estimation apparatus according to a first embodiment of the present invention. It is a flowchart figure which shows operation | movement of the bias estimation apparatus between frequency of the form of Example 1 of this invention.

Explanation of symbols

10a, 10b, 10c Positioning satellite 20 Satellite signal processing system 22 Antenna 24 Satellite signal receiver 26 Satellite signal processing device 30 Ionosphere TEC / bias estimation processing system 32 Inter-frequency bias estimation device 33 Total electron number calculation unit 34 Model value calculation unit 35 Inter-frequency bias estimation unit 36 Random number generation unit 40 Internet data processing system 42 Router 44 GEONET collection data processing device 46 External Internet network 50 Communication line

Claims (4)

An inter-frequency bias estimation apparatus that uses a positioning system that has one or more receivers that receive satellite signals transmitted from a plurality of positioning satellites and obtains position information using positioning information included in the satellite signals. ,
A total electron number calculation unit for calculating the total number of electrons in the passage path of the satellite signal based on a pseudorange from each of the one or more receivers to each of the plurality of positioning satellites;
A model value calculation unit for calculating a total electron number model value based on an ionosphere electron density model function;
A random number generator for generating random numbers;
The inter-frequency bias is calculated based on the total electron number calculated by the total electron number calculating unit and the total electron number model value calculated by the model value calculating unit, and between the frequencies based on the random number generated by the random number generating unit. The receiver-dependent frequency bias and the satellite-dependent frequency bias included in the bias are provisionally determined, position information based on the position measured in advance, and the receiver-dependent frequency bias and the satellite-dependent frequency bias that are provisionally determined. When the error from the position information obtained by positioning the position based on the above is the smallest, the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are estimated to be true values. An inter-frequency bias estimator to perform,
An inter-frequency bias estimation apparatus comprising:   The inter-frequency bias estimator is a position obtained by positioning the position based on position information based on a pre-measured position, and the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias. 2. The inter-frequency bias estimation apparatus according to claim 1, wherein the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are estimated based on a rate of change in error from information.   The inter-frequency bias estimation unit, when the positioning system has a plurality of the receivers, a plurality of the positioning satellites obtained for one positioning satellite based on the positional information obtained by each of the plurality of receivers. 3. The inter-frequency bias estimation apparatus according to claim 1, wherein the inter-satellite dependent frequency bias is estimated by averaging the inter-satellite dependent frequency bias. An inter-frequency bias estimation method using a positioning system that has one or more receivers that receive satellite signals transmitted from a plurality of positioning satellites and obtains position information using positioning information included in the satellite signals. ,
A total electron number calculating step of calculating a total number of electrons of a passage path of the satellite signal based on a pseudo distance from each of the one or more receivers to each of the plurality of positioning satellites;
A model value calculating step for calculating a total electron number model value based on an ionospheric electron density model function;
A random number generation step for generating a random number;
The inter-frequency bias is calculated based on the total electron number calculated by the total electron number calculating step and the total electron number model value calculated by the model value calculating step, and between the frequencies based on the random number generated by the random number generating step. The receiver-dependent frequency bias and the satellite-dependent frequency bias included in the bias are provisionally determined, position information based on the position measured in advance, and the receiver-dependent frequency bias and the satellite-dependent frequency bias that are provisionally determined. When the error from the position information obtained by positioning the position based on the above is the smallest, the receiver-dependent inter-frequency bias and the satellite-dependent inter-frequency bias are estimated to be true values. An inter-frequency bias estimation step,
An inter-frequency bias estimation method comprising:

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