JP2023019895A - Detection method and detection device for satellite for which arrival direction of received signal and satellite azimuth do not match, and gnss receiver - Google Patents

Abstract

To detect a satellite for which an arrival direction of a received signal in GNSS and satellite azimuth do not match, with good accuracy and at least one receiving antenna.SOLUTION: A satellite for which the arrival direction of a received signal for a visible satellite Si and satellite azimuth do not match is detected, on the basis whether an observation code which is a code of a Doppler shift time variation ΔDi with the visible satellite Si calculated based on a satellite positioning signal transmitted from the visible satellite Si matches an inference code which is a code of a Doppler shift time variation with the visible satellite Si inferred from the travelling direction of a GNSS receiver 1 and an orientation in which the visible satellite Si is located, viewed from the GNSS receiver 1 based on satellite orbit information included in the satellite positioning signal.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for detecting a satellite in GNSS (abbreviation of Global Navigation Satellite System; global positioning satellite system) in which the arrival direction of a received signal and the satellite azimuth do not match.

As one method of estimating the direction of arrival of a received signal, it is determined whether or not the received signal from a GPS (Global Positioning System) satellite is affected by multipath. is known (see Patent Document 1).

JP 2010-256301 A

By the way, in the device of Patent Document 1, based on the phase difference between the signals received from each GPS satellite, it is determined whether or not the signal received from each GPS satellite is a signal affected by multipath. . However, the device of Patent Document 1 needs to have a plurality of receiving antennas in order to estimate the direction of arrival based on the information from each GPS satellite.

Therefore, according to the present invention, the direction of arrival of the received signal and the satellite position in the satellite orbit information (specifically, the azimuth of the satellite as seen from the receiving antenna) do not match with good accuracy and at least one receiving antenna. Satellite detection method and detection apparatus capable of detecting satellites where the direction of arrival of the received signal and the satellite azimuth do not match, and detection of the satellite where the direction of arrival of the received signal and the satellite azimuth do not match as described above It is an object to provide a GNSS receiver with a device.

In order to solve the above-mentioned problems, a method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match according to the present invention is based on a positioning satellite that is calculated based on a satellite positioning signal transmitted from the positioning satellite. Observation code, which is the code of the time change amount of Doppler shift, the traveling direction of the receiver that receives the satellite positioning signal while moving with acceleration (or deceleration), and the satellite orbit information included in the satellite positioning signal and an inference code, which is a sign of the time variation of the Doppler shift with the positioning satellite inferred from the azimuth of the positioning satellite as seen from the receiver, and the received signal in the GNSS based on whether or not they match. and detecting a satellite whose direction of arrival and satellite azimuth do not match.

The method of detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match according to the present invention may consider whether or not the observation code is the same over a predetermined length of time.

A method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match according to the present invention includes: The magnitude of the Doppler residual calculated as the difference between the Doppler shift amount, the Doppler shift amount due to movement of the receiver, and the clock drift of the receiver may be considered.

Further, the apparatus for detecting satellites in which the direction of arrival of a received signal and the azimuth of the satellite do not match according to the present invention is a time change amount of Doppler shift with the positioning satellite calculated based on the satellite positioning signal transmitted from the positioning satellite. and the direction of travel of the receiver that receives the satellite positioning signal and the orientation of the positioning satellite as seen from the receiver based on the satellite orbit information contained in the satellite positioning signal. Detecting a satellite for which the direction of arrival of a received signal in GNSS and the satellite azimuth do not match is detected based on whether or not the inference code, which is the code of the time change amount of the Doppler shift with the positioning satellite, matches or not. and

The apparatus for detecting a satellite in which the direction of arrival of the received signal and the satellite azimuth do not match according to the present invention may consider whether the observation code is the same over a predetermined length of time.

According to the present invention, there is provided an apparatus for detecting satellites in which the direction of arrival of a received signal and the satellite azimuth do not match each other. The magnitude of the Doppler residual calculated as the difference between the Doppler shift amount, the Doppler shift amount due to movement of the receiver, and the clock drift of the receiver may be considered.

Further, the GNSS receiver according to the present invention is characterized by comprising a satellite detection device for which the incoming direction of the received signal and the satellite azimuth do not match.

According to the present invention, there is provided a method for detecting a satellite where the direction of arrival of a received signal and the satellite azimuth do not match, a device for detecting a satellite where the direction of arrival of a received signal and the satellite azimuth do not match, and according to a GNSS receiver, Doppler with a positioning satellite Based on whether or not the observed code and the inferred code of the amount of shift change with time match, the satellites for which the direction of arrival of the received signal and the satellite azimuth of the positioning satellite do not match are detected. With at least one receiving antenna, it is possible to detect a satellite for which the direction of arrival of a received signal in GNSS and the satellite azimuth do not match. By detecting satellites whose directions of arrival of received signals do not match satellite azimuths, the receiver can improve positioning accuracy by, for example, excluding positioning satellites affected by multipath from positioning calculations. It becomes possible.

According to the method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, the apparatus for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, and the GNSS receiver according to the present invention, an observation code is a predetermined signal. If consideration is given to whether or not the signal is the same over time, it becomes possible to more accurately detect a satellite for which the direction of arrival of the received signal in the GNSS and the satellite azimuth do not match.

According to the method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, the apparatus for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, and the GNSS receiver according to the present invention, the Doppler residual is large. In the case of considering the height, it becomes possible to more accurately detect the satellite whose arrival direction of the received signal in the GNSS does not match the satellite azimuth.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram showing a schematic configuration of a GNSS receiver provided with a satellite detection device for which the direction of arrival of a received signal and the satellite azimuth do not match, according to an embodiment of the present invention; FIG. 1 shows the processing procedure in the apparatus for detecting satellites in which the direction of arrival of the received signal and the satellite azimuth do not match, and the method of detecting the satellite in which the direction of arrival of the received signal and the satellite azimuth do not match according to the embodiment of the present invention. 4 is a flow chart showing a processing procedure; FIG. 10 is a functional block diagram showing a schematic configuration of a GNSS receiver provided with a satellite detection device for which the direction of arrival of a received signal and the satellite azimuth do not match, according to another embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments.

FIG. 1 is a functional block diagram showing a schematic configuration of a GNSS receiver 1 provided with a satellite detection device 4 in which the direction of arrival of a received signal and the satellite azimuth do not match, according to an embodiment of the present invention. FIG. 2 shows the processing procedure in the satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match. 4 is a flow chart showing the procedure of the method;

The GNSS receiver 1 according to the embodiment receives satellite positioning signals transmitted from each of a plurality of positioning satellites constituting GNSS (abbreviation of Global Navigation Satellite System; global positioning satellite system), and performs satellite positioning of its own position. and a function of detecting a satellite where the arrival direction of the received signal in GNSS and the satellite direction (that is, the direction of the positioning satellite as seen from the GNSS receiver 1) do not match. , a GNSS positioning unit 3, and a satellite detection device 4 where the direction of arrival of a received signal and the satellite azimuth do not match.

The GNSS receiver 1 is, for example, a central processing unit (CPU: abbreviation for Central Processing Unit) that performs arithmetic processing related to satellite positioning of its own position and detection of satellites where the direction of arrival of the received signal in GNSS and the satellite direction do not match. ), ROM (abbreviation for Read Only Memory), which is a readable storage device, and RAM (abbreviation for Random Access Memory), which is a readable and writable storage device. Specifically, for example, the GNSS receiver 1 may be configured by executing a program using a computer, or one or more ICs (abbreviation of Integrated Circuit; integrated circuit) It may be configured in terms of hardware such as.

In this embodiment, the ROM stores a program for controlling the operation of the computer so as to function as the GNSS receiver 1 having the satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match. GNSS receiver 2, GNSS positioning unit 3, and satellites whose directions of arrival of received signals and satellite azimuth do not match are detected by the central processing unit (CPU) executing the program. Each device 4 is implemented as a functional block. Also, RAM is used as a work area as needed.

The GNSS receiver 2 receives satellite positioning signals transmitted from each of a plurality of positioning satellites Si (where i is a satellite number for distinguishing between and identifying each of the plurality of positioning satellites) constituting the GNSS via an antenna. receive it and convert it into an electrical signal (especially a digital signal). Examples of GNSS include GPS (Global Positioning System, an abbreviation for Global Positioning Satellite; Global Positioning System).

The satellite positioning signal is superimposed on a carrier wave and sequentially transmitted from the positioning satellite Si as a radio wave (referred to as "GNSS radio wave"). The GNSS receiver 2 receives GNSS radio waves, demodulates the GNSS radio waves, and extracts satellite positioning signals.

The GNSS receiver 2 obtains observation data such as pseudorange ρi, Doppler shift amount Di, Doppler shift time change amount ΔDi, satellite position, satellite status, and navigation data for each positioning satellite Si from the extracted satellite positioning signals. to generate

The pseudo-range is a distance determined from the difference between the time when the satellite positioning signal (in other words, GNSS radio wave) is transmitted from the positioning satellite Si and the time when it is received by the GNSS receiver 2 via the antenna. The difference between the transmission time and the reception time can be calculated based on the phase shift amount of the C/A code. Note that the C/A code is a unique code for each positioning satellite and functions as information indicating the transmission source.

The pseudorange ρi of each positioning satellite Si is the difference between the time when the positioning satellite Si transmits the satellite positioning signal (GNSS radio wave) and the time when the GNSS receiver 2 receives the satellite positioning signal (GNSS radio wave) (that is, radio wave propagation time) multiplied by the speed of light.

The Doppler shift amount is a parameter that represents the difference between the carrier frequency of the GNSS radio waves caused by the Doppler effect and the reception frequency in the GNSS receiver 2 .

The Doppler shift amount Di of each positioning satellite Si is obtained as a frequency difference between the carrier frequency of the GNSS radio wave transmitted by the positioning satellite Si and the carrier frequency of the GNSS radio wave received by the GNSS receiver 2 . The carrier frequency of the GNSS radio waves transmitted by the positioning satellites Si is determined in advance and stored in advance in a predetermined storage device included in the GNSS receiver 1 (that is, known). That is, the Doppler shift amount Di of each positioning satellite Si is an observed and actually measured value.

The time change amount ΔDi of the Doppler shift of each positioning satellite Si is a parameter representing the time change amount of the Doppler shift amount Di of each positioning satellite Si (that is, the magnitude of change per unit time).

The satellite position is information indicating the current position of the positioning satellite Si on the satellite orbit, and specifically, coordinates in an orthogonal three-dimensional coordinate system.

The satellite position (Xsi, Ysi, Zsi) of each positioning satellite Si is the satellite orbit information (specifically, almanac or ephemeris) of the positioning satellite Si and the time when the positioning satellite Si transmits the satellite positioning signal (GNSS radio wave). calculated based on

The navigation data includes, for example, the satellite number of the positioning satellite Si, satellite orbit information (specifically, almanac or ephemeris), and the time when the satellite positioning signal (GNSS radio wave) was transmitted.

The GNSS receiving unit 2 receives the above observation data at regular intervals (for example, each time a satellite positioning signal is received), for each positioning satellite Si, the signal strength of the satellite positioning signal and the satellite positioning signal (GNSS (radio waves) are output as satellite information along with the time of reception. The GNSS receiver 2 outputs S/N (Signal-to-Noise ratio; Signal-to-noise ratio) and C/N (Carrier-to-Noise ratio; Carrier-to-noise ratio) instead of signal strength. may

The cycle in which the GNSS receiving unit 2 outputs satellite information is not limited to a specific length of time, but it is conceivable that it is set to any length of time within a range of, for example, 50 to 200 milliseconds. .

Moreover, there are a plurality of positioning satellites, and the GNSS receiver 2 generates observation data and satellite information from all satellite positioning signals that can be demodulated from GNSS radio waves, and outputs all the generated satellite information. A positioning satellite that can be used for GNSS satellite positioning (in other words, a positioning satellite that can capture GNSS radio waves and demodulate satellite positioning signals from the GNSS radio waves) is called a "visible satellite", The number of visible satellites is called the "number of visible satellites".

In other words, the GNSS receiver 2 outputs satellite information for each visible satellite Si at a constant cycle, for the number of visible satellites.

The GNSS positioning unit 3 receives input of satellite information for each visible satellite Si output from the GNSS receiving unit 2 at regular intervals, and uses the satellite information to perform arithmetic processing for satellite positioning of its own position.

The method of satellite positioning in the GNSS positioning unit 3 is a well-known technology and there are various methods (for example, Japanese Patent No. 6546730), and the present invention is not limited to a specific method, so detailed description will be given here. omitted.

The GNSS positioning unit 3 outputs at least information indicating the current position of the GNSS receiver 1 (specifically, coordinates in an orthogonal three-dimensional coordinate system) as a result of satellite positioning.

The satellite detection device 4 for which the arrival direction of the received signal and the satellite azimuth do not match is a mechanism for detecting a satellite for which the arrival direction of the received signal in GNSS and the satellite azimuth do not match. A selector 42, a Doppler residual calculator 43, a Doppler residual verifier 44, a DS time variation sign inference unit 45, and a DS time variation sign verification unit 46 (DS: Doppler Shift). omitted).

The satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match receives input of satellite information for each visible satellite Si output from the GNSS receiver 2 at regular intervals. Satellite information is acquired (step S1), and based on the satellite information, arithmetic processing is executed to detect a satellite whose direction of arrival of a received signal in GNSS does not match the satellite azimuth.

The satellite detection apparatus 4 according to the embodiment and the satellite detection method for which the arrival direction of the received signal and the satellite azimuth do not match are satellite positioning transmitted from the visible satellite Si. The GNSS receiver 1 based on the traveling direction of the GNSS receiver 1 and the satellite orbit information contained in the satellite positioning signal, and the observation code that is the code of the time variation ΔDi of the Doppler shift with respect to the visible satellite Si calculated based on the signal. The received signal for the visible satellite Si is determined based on whether or not the azimuth at which the visible satellite Si is located from the viewpoint of the visible satellite Si coincides with the inferred sign, which is the sign of the time change amount of the Doppler shift with the visible satellite Si. Detect satellites whose direction of arrival and satellite azimuth do not match.

The satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match receives the input of the satellite information for each visible satellite Si output from the GNSS receiver 2 at regular intervals (step S1), and after step S2. are executed, the processing after step S3 is executed for each visible satellite Si, and the processing after step S4 is executed for each visible satellite Si selected in the processing of step S3. Then, the satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match is generated for each visible satellite Si for which the direction of arrival of the received signal and the satellite azimuth do not match. determine whether there is

A satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match uses the Doppler residual to detect the satellite for which the direction of arrival of the received signal and the satellite azimuth do not match from among a plurality of satellite positioning signals. detect. By using the Doppler residual, for example, when the satellite positioning signal arrives at the GNSS receiver 1 from a direction different from the actual position of the visible satellite due to the influence of multipath, the satellite line-of-sight vector of the actual visible satellite Si , the detection accuracy of the satellite positioning signal affected by multipath is improved and erroneous detection is reduced.

The satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match can also be inferred from the direction of travel of the GNSS receiver 1 and the relative positional relationship between the GNSS receiver 1 and each visible satellite Si. A satellite positioning signal of a satellite whose arrival direction of the received signal does not match the satellite azimuth is detected from among a plurality of satellite positioning signals based on the direction of change of the Doppler shift time variation ΔDi with respect to each visible satellite Si. .

Then, when there is no satellite where the arrival direction of the received signal in GNSS and the satellite azimuth do not match, and the positioning satellite is located in front of the GNSS receiver 1 in the traveling direction, the acceleration of the GNSS receiver 1 is Since the GNSS receiver 1 and the positioning satellite relatively approach each other due to the accompanying movement, the sign of the time variation of the Doppler shift becomes positive.

On the other hand, when there is no satellite where the arrival direction of the received signal in GNSS and the satellite azimuth do not match, and the positioning satellite is located behind the GNSS receiver 1 in the traveling direction, the acceleration of the GNSS receiver 1 is Since the GNSS receiver 1 and the positioning satellite move relatively away from each other due to the accompanying movement, the sign of the time variation of the Doppler shift becomes negative.

On the other hand, when there is a satellite whose direction of arrival of the received signal in the GNSS does not match the satellite azimuth, the positioning satellite is positioned in front of the GNSS receiver 1 in the direction of travel, and if the direction of arrival of the received signal If the signal from the satellite that causes the satellite azimuth to differ from The sign of the Doppler shift with time change is positive Contrary to expectations, the sign of the Doppler shift with time change is negative. Also, in this case, the Doppler residual becomes large.

In addition, when there is a satellite whose arrival direction of the received signal in GNSS and the satellite azimuth do not match, the positioning satellite is positioned behind the GNSS receiver 1 in the traveling direction, and if the arrival direction of the received signal and the satellite azimuth When the satellite signal that does not match exists in front of the GNSS receiver 1 in the traveling direction, the GNSS receiver 1 moves with acceleration, and if the signal is from the original positioning satellite, the Doppler shift The Sign of the Time Variation Becomes Negative Contrary to expectations, the sign of the time variation of the Doppler shift becomes positive. Also, in this case, the Doppler residual becomes large.

For this reason, the Doppler residual is large, the sign of the observed value of the time variation ΔDi of the Doppler shift with respect to the visible satellite Si, the direction of the visible satellite Si as seen from the GNSS receiver 1, and the traveling direction of the GNSS receiver 1 If the sign of the time variation of the Doppler shift with the visible satellite Si inferred from the above does not match, there is a satellite with a mismatch between the direction of arrival of the received signal and the satellite azimuth for the visible satellite Si (possible high potential).

The satellite detection device 4 for which the direction of arrival of the received signal and the satellite azimuth do not match is based on the above concept to detect the satellite for which the direction of arrival of the received signal in GNSS and the satellite azimuth do not match for each visible satellite Si. each part executes the following processing.

The acceleration vector calculator 41 calculates the acceleration vector of the GNSS receiver 1 (step S2).

The method of calculating the acceleration vector of the GNSS receiver 1 is a well-known technique, there are various methods, and the present invention is not limited to a specific method, so detailed description is omitted here.

The acceleration vector calculator 41 calculates the relative acceleration of the GNSS receiver 1 with respect to each visible satellite Si based on the time change amount ΔDi of the Doppler shift included in the satellite information for each visible satellite Si, and Based on the satellite orbit information (specifically, almanac and ephemeris) included in the satellite information for each Si and the time when the positioning satellite Si transmitted the satellite positioning signal (GNSS radio wave), the acceleration vector of each visible satellite Si is calculated. calculate.

The acceleration vector calculator 41 also combines the information indicating the current position of the GNSS receiver 1 output from the GNSS positioning unit 3 (specifically, the coordinates in an orthogonal three-dimensional coordinate system) with the satellite information for each visible satellite Si. Based on the included satellite positions (Xsi, Ysi, Zsi), the direction of each visible satellite Si viewed from the GNSS receiver 1 (specifically, the direction of each visible satellite Si viewed from the GNSS receiver 1 ).

The acceleration vector calculator 41 further calculates the relative acceleration of the GNSS receiver 1 with respect to each visible satellite Si calculated above, the acceleration vector of each visible satellite Si, and the direction of each visible satellite Si viewed from the GNSS receiver 1. to calculate the acceleration of the GNSS receiver 1 for each direction of each visible satellite Si, and calculate the acceleration vector of the GNSS receiver 1 based on the acceleration of the GNSS receiver 1 for each direction of each visible satellite Si. .

Alternatively, the acceleration vector calculator 41 may calculate the acceleration vector of the GNSS receiver 1 based on information output from the acceleration sensor 5 and information output from the gyro sensor 6 (or yaw rate sensor). Good (see Figure 3).

The acceleration sensor 5 detects and outputs the acceleration of the GNSS receiver 1, in other words, the acceleration of a moving object (for example, vehicle, ship, aircraft, etc.) on which the GNSS receiver 1 is mounted.

The gyro sensor 6 (or yaw rate sensor) detects and outputs the yaw rate of the GNSS receiver 1, in other words, the yaw rate of the mobile body (for example, vehicle, ship, aircraft, etc.) on which the GNSS receiver 1 is mounted. do.

In this case, the acceleration vector calculation unit 41 receives an input of the detected acceleration output from the acceleration sensor 5, receives an input of the detected yaw rate output from the gyro sensor 6, and receives the input of the detected yaw rate. The yaw rate is integrated based on to calculate the amount of change in the yaw angle (in other words, the azimuth angle) to calculate the traveling direction of the GNSS receiver 1, and the GNSS based on the traveling direction and the detected value of the acceleration Calculate the acceleration vector of the receiver 1 . At least once, the actual direction of travel (in other words, azimuth) is determined and given as a reference/initial value.

The satellite selection unit 42 selects a visible satellite Si to be subjected to processing for detecting a satellite for which the arrival direction of the received signal and the satellite azimuth do not match (step S3).

The satellite selection unit 42 first determines the Doppler shift contained in the satellite information acquired in the process of step S1 (including the process of the latest step S1) for the most recent N times (where N is a natural number) in time series. is used to generate a set of Doppler shift time variations .DELTA.Di for each visible satellite Si.

N in the above (referred to as “number of times of continuation N”) is not limited to a specific value (in other words, length of time). Based on this, it is appropriately set to an appropriate value, taking into account that it is possible to appropriately determine whether or not the positioning signals are signals transmitted/sent from the same direction. For example, when the satellite information is output from the GNSS receiving unit 2 every 100 milliseconds and the GNSS positioning unit 3 executes the arithmetic processing of satellite positioning of its own position, the number of continuations N is about 3 to 5 (that is, , 300 to 500 milliseconds).

Subsequently, the satellite selection unit 42 determines whether or not the signs of the Doppler shift time variations ΔDi included in the set of the Doppler shift time variations ΔDi (that is, for the number of consecutive N times) are the same. to decide.

Then, if the signs of the time variation ΔDi of the Doppler shift for the number N times of continuation are different (step S3: No), the satellite selection unit 42 determines that the arrival direction of the received signal and the satellite azimuth for the visible satellite Si are It is determined that no mismatching satellite has occurred (step S8).

On the other hand, if the signs of the time variation ΔDi of the Doppler shift for the number N of continuations are all the same (step S3: Yes), the satellite selection unit 42 determines the direction of arrival of the received signal and the satellite azimuth for the visible satellite Si. The processing procedure for detecting satellites that do not match is advanced to the processing of step S4.

When the signs of the time variation ΔDi of the Doppler shift for the number N of continuations are all the same, the GNSS receiver 1 and the source of the signal (in addition, the arrival direction of the received signal and the satellite azimuth (including the source of the satellite signal that causes a mismatch) continues to approach or recede with acceleration.

The Doppler residual calculator 43 calculates the Doppler residual (step S4).

Specifically, the Doppler residual calculator 43 calculates the Doppler residual Ri of the visible satellite Si according to Equation 1 below. The Doppler residual Ri of the visible satellite Si is the Doppler shift amount Di with respect to the visible satellite Si, the Doppler shift amount Dsi due to movement of the visible satellite Si, the Doppler shift amount Dr due to movement of the GNSS receiver 1, and the GNSS It is the difference between the sum of the clock drifts Δfrc of the receiver 1 and the total clock drift Δfrc.
(Formula 1) Ri = Di - (Dsi + Dr + Δfrc)
where Ri: Doppler residual of visible satellite Si
Di: Doppler shift amount with visible satellite Si
Dsi: Doppler shift due to movement of visible satellite Si
Dr: Doppler shift amount due to movement of GNSS receiver 1
Δfrc: clock drift of GNSS receiver 1

Specifically, Dsi is the Doppler shift amount in the satellite line-of-sight direction with respect to the visible satellite Si due to the change in the relative distance due to the movement of the visible satellite Si, and is the velocity vector of the visible satellite Si and the current position of the GNSS receiver 1 ( Specifically, it is calculated as a quantity for the satellite line-of-sight direction of the visible satellite Si based on the coordinates in an orthogonal three-dimensional coordinate system.

Specifically, Dr is the Doppler shift amount in the satellite line-of-sight direction with respect to the visible satellite Si due to the change in the relative distance due to the movement of the GNSS receiver 1, and the velocity vector of the GNSS receiver 1 and the satellite position of the visible satellite Si (Xsi, Ysi, Zsi) and calculated as a quantity for the satellite line-of-sight direction of the visible satellite Si.

Δfrc is the clock drift of the GNSS receiver 1, and is successively estimated by the GNSS receiver 1 itself by receiver velocity calculation using the least squares method, Kalman filter, or the like.

The Doppler residual verifier 44 determines whether or not the absolute value of the Doppler residual Ri of the visible satellite Si is greater than or equal to the Doppler residual threshold Rthr (step S5).

The Doppler residual threshold value Rthr is not limited to a specific value. It is appropriately set to an appropriate value after taking into account that it is possible to appropriately detect that it deviates from. The Doppler residual threshold value Rthr may be set, for example, to any value within a range of approximately 0.6/λ to 2.0/λ [Hz]. However, λ is the wavelength [m] of the carrier wave, and the Doppler shift amount d [Hz] is expressed by d=v/λ, where v [m/s] is the relative moving speed.

Then, if |Ri| It is determined that there is no satellite whose azimuths do not match (step S8).

On the other hand, if |Ri|≧Rthr (step S5: Yes), the Doppler residual verification unit 44 performs a processing procedure for detecting a satellite for which the direction of arrival of the received signal for the visible satellite Si does not match the satellite azimuth. is advanced to the processing of step S6.

The DS time variation sign deduction unit 45 deduces whether the sign of the time variation ΔDi of the Doppler shift with respect to the visible satellite Si is expected to be positive or negative (step S6). .

Specifically, the DS time change amount sign inference unit 45 determines the traveling direction of the GNSS receiver 1 based on the acceleration vector of the GNSS receiver 1 calculated in the process of step S2 and the satellite information. Based on the ephemeris-based relative relationship between the azimuth of the visible satellite Si as seen from the GNSS receiver 1 and the time change amount ΔDi of the Doppler shift with respect to the visible satellite Si, should the sign be positive? Infer what should be negative.

That is, based on the traveling direction of the GNSS receiver 1 and the azimuth of the visible satellite Si, when the GNSS receiver 1 and the visible satellite Si are approaching with acceleration, the Doppler shift between the visible satellite Si is The time variation ΔDi should be positive, while the time variation ΔDi of the Doppler shift with respect to the visible satellite Si becomes negative when the GNSS receiver 1 accompanies acceleration and the visible satellite Si moves away. should be.

The DS time variation sign verification unit 46 determines the sign (referred to as the "observation code") of the Doppler shift time variation ΔDi included in the satellite information for each visible satellite Si and inferred in the process of step S6. It is determined whether or not the code of the Doppler shift with time (referred to as the "inference code") matches that of the visible satellite Si (step S7).

Then, if the observed code of the Doppler shift time variation and the inference code match (step S7: Yes), the DS time variation code verification unit 46 determines the observed value of the Doppler shift time variation ΔDi. Since the codes are not inconsistent, it is determined that there is no satellite in which the direction of arrival of the received signal and the satellite azimuth do not match with respect to the visible satellite Si (step S8).

On the other hand, if the observed code of the Doppler shift time variation does not match the inference code (step S7: No), the DS time variation code verification unit 46 determines the observed value of the Doppler shift time variation ΔDi. Since the codes are inconsistent, it is determined that there is a satellite in which the arrival direction of the received signal and the satellite azimuth do not match with respect to the visible satellite Si (step S9).

When the direction of arrival of the received signal and the satellite azimuth do not match, the satellite detection device 4 detects a satellite for which the direction of arrival of the received signal and the satellite azimuth do not match among the visible satellites Si. The satellite information about the visible satellites Si may be excluded from the information. The user may be notified by displaying a message on a display (not shown) or emitting a sound through a speaker (not shown).

According to the method for detecting a satellite where the direction of arrival of a received signal and the satellite azimuth do not match, the device 4 for detecting a satellite where the direction of arrival of a received signal and the satellite azimuth do not match, and the GNSS receiver 1, a visible satellite Based on whether or not the observed code and inferred code of the Doppler shift time variation ΔDi with respect to Si match, a satellite for which the direction of arrival of the received signal and the satellite azimuth of the visible satellite Si do not match is detected. Therefore, it is possible to detect a satellite with good accuracy and at least one receiving antenna for which the direction of arrival of the received signal in GNSS and the satellite azimuth do not match.

According to the method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, the detection device 4 for a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, and the GNSS receiver 1 according to the embodiment, This is because it is considered whether or not the sign (i.e. observation code) of the time change amount ΔDi of the Doppler shift with respect to the visible satellite Si is the same over the number of consecutive N times (in other words, a predetermined length of time). , it is possible to more accurately detect a satellite for which the direction of arrival of a received signal in the GNSS and the satellite azimuth do not match.

According to the method for detecting a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, the detection device 4 for a satellite in which the direction of arrival of a received signal and the satellite azimuth do not match, and the GNSS receiver 1 according to the embodiment, Since the magnitude of the Doppler residual is taken into account, it becomes possible to more accurately detect a satellite for which the direction of arrival of the received signal in the GNSS and the satellite azimuth do not match.

Although the embodiments of the present invention have been described above, the specific configuration is not limited to the above-described embodiments. Included in the invention.

For example, in the above-described embodiment, the GNSS receiver 1 whose schematic configuration is shown in FIG. Devices/devices in which the satellite detection device 4 according to the present invention in which the direction of arrival of the received signal and the satellite azimuth do not match are incorporated or cooperated are limited to the GNSS receiver 1 whose schematic configuration is shown in FIG. Instead, a satellite detection device according to the present invention, in which the direction of arrival of the received signal and the satellite azimuth do not match, may be incorporated in or linked to a GNSS receiver having another configuration. The satellite detection device in which the direction of arrival of the received signal and the satellite azimuth do not match is incorporated in other types of equipment or devices that use GNSS, or is linked with other types of equipment or devices that use GNSS. More specifically, the satellite detection apparatus according to the present invention, in which the arrival direction of the received signal and the satellite azimuth do not match, may be used alone. In addition, the GNSS receiver 2 performs arithmetic processing for detecting a satellite for which the arrival direction of the received signal and the satellite azimuth do not match the satellite detection device 4 detects a satellite for which the arrival direction of the received signal in GNSS and the satellite azimuth do not match. It is possible to output only the observation data/satellite information necessary for .

Further, in addition to the configuration in the above embodiment, for example, when a certain number or more of positioning satellites are detected as positioning satellites in which the direction of arrival of the received signal and the satellite azimuth do not match, the positioning accuracy decreases. If it is determined that there is a risk, satellite positioning may be interrupted. In that case, if a gyro sensor or an acceleration sensor can be used, it may be switched to inertial navigation.

Further, as an example of utilization of the above embodiment, for example, when a transmission signal containing positioning information and orbit information of a plurality of positioning satellites is transmitted from a single transmission antenna and the transmission signal is received by a receiver, By applying the present invention, it becomes possible to detect a satellite where the arrival direction of the received signal and the satellite azimuth do not match. In addition, it can be said that the above situation pretends that signals are being transmitted from a plurality of positioning satellites. In this regard, the "signals transmitted from a plurality of positioning satellites" in the present invention include signals transmitted from a single transmission antenna while pretending that signals are transmitted from a plurality of positioning satellites.

1 GNSS receiver 2 GNSS receiving unit 3 GNSS positioning unit 4 Satellite detection device where the arrival direction of the received signal and the satellite azimuth do not match 41 Acceleration vector calculation unit 42 Satellite selection unit 43 Doppler residual calculation unit 44 Doppler residual verification unit 45 Sign Inference Unit for Time Variation of DS 46 Sign Verification Unit for Time Variation of DS 5 Acceleration Sensor 6 Gyro Sensor

Claims (7)

an observation code that is a code of a time change amount of Doppler shift with the positioning satellite calculated based on a satellite positioning signal transmitted from the positioning satellite;
Doppler shift with the positioning satellite inferred from the traveling direction of the receiver that receives the satellite positioning signal and the azimuth at which the positioning satellite is located viewed from the receiver based on the satellite orbit information contained in the satellite positioning signal an inference code that is the code of the amount of change over time;
detecting a satellite for which the direction of arrival of the received signal for the positioning satellite and the satellite azimuth do not match, based on whether or not the
A method of detecting a satellite in which the direction of arrival of a received signal and the azimuth of the satellite do not match. considering whether the observation code is the same over a predetermined length of time;
2. The method of detecting a satellite where the direction of arrival of a received signal and the azimuth of the satellite do not match according to claim 1. A measured Doppler shift amount with respect to the positioning satellite observed based on the satellite positioning signal, a Doppler shift amount due to movement of the positioning satellite, a Doppler shift amount due to movement of the receiver, and a clock drift of the receiver Considering the magnitude of the Doppler residual computed as the sum of and the difference between
3. The method of detecting a satellite according to claim 1 or 2, wherein the direction of arrival of the received signal and the azimuth of the satellite do not match. an observation code that is a code of a time change amount of Doppler shift with the positioning satellite calculated based on a satellite positioning signal transmitted from the positioning satellite;
Doppler shift with the positioning satellite inferred from the traveling direction of the receiver that receives the satellite positioning signal and the azimuth at which the positioning satellite is located viewed from the receiver based on the satellite orbit information contained in the satellite positioning signal an inference code that is the code of the amount of change over time;
detecting a satellite for which the direction of arrival of the received signal for the positioning satellite and the satellite azimuth do not match, based on whether or not the
2. A satellite detection device characterized by the fact that the arrival direction of a received signal and the satellite azimuth do not match. considering whether the observation code is the same over a predetermined length of time;
5. A satellite detection apparatus according to claim 4, wherein the direction of arrival of the received signal and the azimuth of the satellite do not match. A measured Doppler shift amount with respect to the positioning satellite observed based on the satellite positioning signal, a Doppler shift amount due to movement of the positioning satellite, a Doppler shift amount due to movement of the receiver, and a clock drift of the receiver Considering the magnitude of the Doppler residual computed as the sum of and the difference between
6. The apparatus for detecting satellites according to claim 4 or 5, wherein the direction of arrival of the received signal and the azimuth of the satellite do not match. A satellite detection device according to any one of claims 4 to 6, wherein the arrival direction of the received signal and the satellite azimuth do not match,
A GNSS receiver characterized by:

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