JPH07167936A - Signal receiving device of satellite navigation method and moving body position measuring system - Google Patents

Abstract

PURPOSE:To prevent erroneous pursuit of carrier phase in the event of signal interruption and enable continuing the pursuit of the carrier phase immediately after restitution of the signal. CONSTITUTION:From a position measuring satellite, a signal receiving circuit 1 receives electric waves which are spectrum diffused due to pseudo noise code, and an IQ separator circuit 2 separates it into an in-phase component and an orthogonally intersecting component, and a carrier component removing circuit 3 removes the carrier component. A C/A synchronizing circuit 4 generates synchronization with the C/A code to make spectrum reverse diffusion, and a carrier signal regeneration circuit 7 regenerates the carrier signal, and a phase error extracting circuit 5 determines the phase error of the regenerated carrier signal from the received carrier signal. A loop filter 6 controls the frequency of carrier signal to be regenerated from the determined phase error, and a signal intensity sensing circuit 9 nullifies the phase error data for the loop filter 6 in the case of sunk intensity of the signal which has undergone spectrum reverse diffusion due to signal interruption, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite navigation receiver in a positioning system such as GPS and a mobile positioning system using the same.

[0002]

2. Description of the Related Art A satellite navigation receiving apparatus used in a GPS positioning system receives a code-modulated positioning radio wave having a constant period transmitted from a plurality of navigation satellites and included in a received signal when performing a single positioning. The position of the receiving point is obtained from the distance from each navigation satellite to the receiving point and the orbit information of each navigation satellite in synchronization with the phase of the code and the phase of the carrier of the received signal, and the moving direction of the receiving point from the Doppler effect of the carrier. And the moving speed.

A satellite navigation receiver for interferometric positioning is provided as a reference station at a known point and as a mobile station in a mobile body, and counts the carrier phase of each received signal and obtains the phase count value obtained by the reference station. The relative position of the mobile body with respect to the reference station, which has a base line between the reference station and the mobile station, is located based on the phase difference from the phase count value obtained by the mobile station.

In any of the receivers, an oscillator circuit for generating a reproduced carrier signal for synchronizing with the carrier phase, and a phase error detector for detecting a phase error between the received carrier signal and the reproduced carrier signal. And a loop filter that controls the oscillation circuit based on the phase error, thereby forming a phase-locked loop (PLL) circuit.

Further, when performing interferometric positioning, reception may be momentarily interrupted due to the influence of obstacles, noise radio waves, and multiple reflections on radio waves from satellites. The phase-locked loop becomes inoperable,
During that time, when the oscillation circuit is in the free-run state, and as a result, when the reception is restarted, the phase relationship up to that time and 36
Jumps that are integral multiples of 0 °, so-called cycle slips, occur. In order to prevent such cycle slips, we have been devising antenna installation locations and operational points. If it is found in the post-processing stage that a cycle slip has occurred, the cycle slip is corrected where possible by editing the recorded phase data.

[0006]

The conventional PLL filter for synchronizing the carrier phase operates under the condition that the received signal (observed signal) is always present. Therefore, even while the reception signal is blocked, the phase of the noise input to the PLL filter is tracked, and after the reception signal returns, the oscillation frequency deviates more than the pullable frequency of the phase-locked loop. However, there was a problem that phase tracking could not be continued immediately.

The object of the present invention is to prevent the synchronization shift from the carrier phase during the interruption to be minimized even if such a reception signal interruption occurs so that it falls within the pull-in frequency after the signal is restored. An object of the present invention is to provide a satellite navigation receiver that solves the above problem.

Further, in the conventional satellite navigation receiver for interferometric positioning, the occurrence of cycle slip is only detected in the post-processing stage of positioning by processing the accumulated phase data and observing. It was not possible to immediately know that a cycle slip had occurred in the car.

Another object of the present invention is to provide a satellite navigation receiver capable of immediately detecting that a cycle slip has occurred during observation.

Further, in the conventional positioning system for positioning the relative position of the mobile station with respect to the reference station by interferometric positioning, if the occurrence of a cycle slip is detected in the land mobile, the mobile station is stopped and recalibrated on the spot. However, for example, in a marine survey using a survey ship, the survey ship could not be stopped instantaneously, and remeasurement at the place where the cycle slip occurred was impossible.

Another object of the present invention is to perform positioning of a moving body so that even if a cycle slip occurs on the way, the moving body is not stopped and the moving route of the moving body can be sequentially and sequentially set as a relative position with respect to a reference station. To provide a system.

[0012]

A satellite navigation receiving apparatus according to claim 1 of the present invention includes a receiving means for receiving radio waves from a positioning satellite whose spectrum is spread by a pseudo noise code, and a receiving signal. Code synchronizing means for synchronizing the pseudo noise code, carrier signal reproducing means for reproducing the carrier signal included in the received signal, and phase comparison between the reproduced carrier signal reproduced by the carrier signal reproducing means and the received signal. In a satellite navigation receiver equipped with a phase error extracting means for obtaining a phase error and a loop filter means for determining the frequency of a reproduced carrier signal which is synchronized with the carrier phase of a received signal from the phase error, the spectrum is despread by code synchronization. The signal strength is compared with the reference strength, and when the strength is less than the reference strength, the phase error for the loop filter is Is set to 0, and phase error switching means for setting the phase error for the loop filter to the phase error obtained by the phase error extracting means when the intensity of the spectrum despread signal is equal to or higher than the reference intensity is provided. And

A satellite navigation receiving apparatus according to a second aspect stores phase error data integrating means for sequentially integrating the phase error data in the first aspect to obtain frequency change data, and a moving average value of the frequency change data. An average frequency variation data storage means, a frequency variation data integrating means for integrating frequency variation data to obtain frequency data, and weighting and adding the phase error data, frequency variation data and frequency data. Frequency control data calculating means for obtaining frequency control data of the reproduced carrier signal by means of, and when the phase error is switched to 0 by the phase error switching means, the frequency of which the content of the frequency change data storage means is the frequency change data. The loop filter means is composed of a change data switching means. .

The satellite navigation receiving apparatus according to a third aspect of the present invention is different from the satellite navigation receiving apparatus according to the second aspect in that it further includes a speed measuring means for measuring the speed of the receiving apparatus and a change in the speed obtained by the speed measuring means. From the frequency change amount variation amount predicting means for predicting the variation amount of the frequency variation amount, and a frequency change correcting the variation amount of the frequency variation amount with respect to the average frequency change amount data obtained by the average frequency variation amount data storage means. A minute data correction means is provided.

According to a fourth aspect of the present invention, in the satellite navigation receiving apparatus, the carrier signal reproducing means comprises a reference oscillator for generating a reference frequency signal and a frequency variable oscillation circuit for generating a carrier signal based on the reference frequency signal. In addition to the satellite navigation receiving device according to Item 2, a reference oscillator temperature measuring means for further measuring the temperature of the reference oscillator, and a variation amount of the frequency change data based on a change in temperature measured by the reference oscillator temperature measuring means. A frequency change amount prediction unit for predicting and a frequency change data correction unit for correcting the change amount of the frequency change amount with respect to the average frequency change data obtained by the average frequency change data storage unit are provided. Characterize.

A satellite navigation receiving device according to a fifth aspect of the present invention includes a receiving means for receiving radio waves from a positioning satellite that are repeatedly modulated by navigation message data composed of a plurality of bits.
Satellite navigation provided with carrier signal reproducing means for reproducing the carrier signal included in the received signal, phase angle integrating means for integrating the phase angle of the reproduced carrier signal, and navigation message data demodulating means for demodulating navigation message data. The receiving device is provided with a bit data length determining means for determining whether or not each bit data forming the demodulated navigation message data continues for a predetermined one bit time, and the bit data length determining means is provided. According to the result of
It is characterized in that the presence or absence of cycle slip occurring when the phase angle of the reproduction carrier signal is integrated is detected.

A satellite navigation receiving device according to a sixth aspect of the present invention includes a receiving means for receiving radio waves from a positioning satellite that is repeatedly modulated by navigation message data consisting of a plurality of bits.
Satellite navigation provided with carrier signal reproducing means for reproducing the carrier signal included in the received signal, phase angle integrating means for integrating the phase angle of the reproduced carrier signal, and navigation message data demodulating means for demodulating navigation message data. In the receiving device, a code pattern extraction unit that extracts a code pattern that appears repeatedly in the demodulated navigation message data, and a code pattern appearance determination unit that determines whether or not the extracted code pattern appears in a predetermined cycle. It is characterized in that the presence or absence of a cycle slip that occurs when the phase angle of the reproduction carrier signal is integrated is detected based on the result of the code pattern appearance determining means.

A satellite navigation receiving apparatus according to a seventh aspect of the present invention is a receiving means for receiving a radio wave from a positioning satellite, a carrier signal reproducing means for reproducing a carrier signal included in the received signal, and a phase of the reproduced carrier signal. In a satellite navigation receiver equipped with a phase angle accumulating means for accumulating angles, an orthogonal component extracting means for extracting an orthogonal component of a carrier frequency of a received signal and an absolute component of the orthogonal component from which the carrier component has been removed by the carrier component removing means. Absolute value extraction means for obtaining the value,
A moving average value extracting means for obtaining a moving average value of the absolute value in a fixed time, a comparing means for comparing the absolute value with a reference value obtained from the moving average value, and a comparison result of the comparing means. The presence or absence of cycle slip occurring when the phase angles of the reproduced carrier signals are integrated is detected.

According to another aspect of the mobile positioning system of the present invention, the receiving means receives the radio wave from the positioning satellite, the carrier signal reproducing means reproduces the carrier signal contained in the received signal, and the phase of the reproduced carrier signal. A reference station installed at a known fixed point, comprising a phase angle integrating means for integrating the angles to obtain phase angle integrated value data and a phase angle integrated value data transmitting means for wirelessly transmitting the phase angle integrated value data, and a mobile unit. Receiving means for respectively receiving radio waves from the positioning satellite at a plurality of points having a relatively fixed positional relationship above, carrier signal reproducing means for reproducing a carrier signal included in each received signal, and each reproduced signal. Phase angle integration means for calculating the phase angle integration value data by integrating the phase angle of the carrier signal, and a phase angle integration value data receiver for receiving the phase angle integration value data transmitted from the reference station. And the phase angle integrated value data received by the phase angle integrated value data receiving means, the phase angle integrated value data received at the plurality of points, the reference point position information, and the positioning satellite position information. Relative position vector calculating means for calculating relative position vectors of a plurality of receiving points on the moving body with respect to a point, relative position vectors between respective receiving points on the moving body obtained by the relative position vector calculating means, and each on the moving body Relative position vector comparison means for comparing with a known relative position vector between receiving points, and cycle slip generation for judging a receiving point where a cycle slip has occurred at the time of integrating the phase angle of the reproduced carrier signal from the comparison result And a mobile station provided on the mobile body, which comprises a point determination means.

A mobile positioning system according to a ninth aspect of the present invention is the same as the mobile positioning system according to the eighth aspect, further including a phase angle due to reception at a reception point at which a cycle slip occurrence point is determined by the cycle slip occurrence point determination means. It is characterized in that a cycle slip correcting means for correcting the cycle slip by the integrated value is provided.

[0021]

In the satellite navigation receiving apparatus according to the first aspect, the phase error extracting means obtains a phase error by comparing the phase of the reproduced carrier signal reproduced by the carrier signal reproducing means with the received signal, and the loop filter means makes the phase error. Determines the frequency of the reproduction carrier signal synchronized with the carrier phase of the received signal. Then, the phase error switching means compares the intensity of the signal despread by the code synchronization with the reference intensity. When the intensity is less than the reference intensity, the phase error for the loop filter is set to 0, and the intensity of the signal is equal to or higher than the reference intensity. The phase error for the loop filter is switched as the phase error obtained by the phase error extracting means.

Here, FIG. 1 is a block diagram showing an example of the configuration of the main part of the satellite navigation receiving apparatus according to the first aspect. In FIG. 1, a receiving circuit 1 receives a radio wave from a satellite, and an IQ separation circuit 2
Is the in-phase component (I signal) and quadrature component (Q signal)
To separate. The carrier component removal circuit 3 multiplies the I signal and the Q signal by the reproduced carrier signal to remove the carrier component. The C / A code synchronization circuit 4 performs spectrum despreading by integrating the C / A code synchronized with the C / A code included in the received signal. The phase error extraction circuit 5 extracts the phase error between the carrier signal included in the received signal and the reproduced carrier signal. The loop filter 6 controls the carrier signal reproducing circuit 7 from the phase error. The reference oscillator 8 generates a reference frequency signal. The carrier signal reproducing circuit 7 controls the frequency of the reproduced carrier signal according to the output of the loop filter 6 based on the reference frequency signal. The signal strength detection circuit 9 compares the signal strength of the in-phase component subjected to spectrum despreading with the reference strength. When the signal intensity of the in-phase component subjected to spectrum despreading is higher than the reference intensity,
The phase error extracted by the phase error extraction circuit 5 is given to the loop filter 6, and when the signal strength does not reach the reference strength, the phase error for the loop filter 6 becomes zero.

In the state where the received signal is not interrupted, the phase error extraction circuit 5, the loop filter 6, the carrier signal reproduction circuit 7 and the carrier component removal circuit 3 synchronize the carrier phase by the phase lock loop and the signal is interrupted. However, if the intensity is extremely reduced, the phase error with respect to the loop filter 6 becomes 0, so that the carrier signal reproducing circuit 7 continues to reproduce the last carrier frequency before the signal interruption. Therefore, if there is little change in the relative speed between the positioning satellite and the receiving device during signal interruption, the frequency of the reproduced carrier signal during signal interruption almost tracks the actual carrier frequency, and the frequency that can be pulled in until the signal returns. It can fit within the range.

In the satellite navigation receiving apparatus according to a second aspect, the loop filter means according to the first aspect includes a phase error data integrating means, an average frequency change data storage means, a frequency control data calculating means, and a frequency change data switching means. The phase error integrating means sequentially integrates the phase error data to obtain frequency change data, and the average frequency change data storage means stores the moving average value of the frequency change data.
The frequency change data integration means integrates the frequency change data to obtain frequency data. The frequency control data calculation means determines the frequency control data of the reproduced carrier signal by weighting and adding the phase error data, the frequency change data and the frequency data. Then, the frequency change data switching means switches the content of the frequency change data storage means as frequency change data when the phase error is switched to 0 by the phase error switching means according to the first aspect.

FIG. 2 is a block diagram showing an example of the configuration of the main part of the satellite navigation receiving apparatus according to the second aspect. In FIG. 2, the integrating circuit 10 corresponds to the phase error integrating means, the averaging circuit 11 and the memory 12 correspond to the average frequency change data storing means, the integrating circuit 13 corresponds to the frequency change data integrating means, and the weighting circuit 14 , 15, 16 and the adder circuit 17 correspond to frequency control data calculating means. The switches SW1 and SW2 show a normal state in which the signal is not interrupted. In this state, the averaging circuit 11 takes a moving average of the frequency change amount due to the integration of the phase error, and the memory 12 stores it.
If the signal is interrupted, the switch SW1 is opened and the switch SW2 is switched to the b side. In this state, the contents of the memory 12 are used as frequency change data. Therefore, even if the signal is interrupted while the positioning satellite and the receiving device are moving relatively with acceleration, the carrier phase is estimated and tracked while the signal is interrupted.

In the satellite navigation receiving device according to claim 3, the speed measuring means measures the speed of the receiving device, and the frequency change amount fluctuation amount predicting means determines the speed change during interruption of the measured signal. Predict how much the frequency change of will fluctuate. Then, the frequency change data correction means corrects the variation amount of the frequency change obtained for the average frequency change data. Therefore, even if the relative speed change between the positioning satellite and the receiving device fluctuates during the interruption of the signal, the carrier phase can be more accurately predicted and tracked.

According to another aspect of the satellite navigation receiving apparatus of the present invention, the reference oscillator temperature measuring means measures the temperature of the reference oscillator, and the frequency change amount prediction means changes the frequency change amount from the measured change of the reference oscillator temperature. Predict the amount of fluctuation. Then, the frequency change data correction means corrects the variation amount of the predicted frequency change with respect to the average frequency change. Therefore, even when the temperature of the reference oscillator changes during the interruption of the signal, the predicted tracking of the carrier phase is performed according to the temperature change, and the tracking of the carrier phase can be continued after the signal is restored.

In the satellite navigation receiving apparatus according to the present invention, the receiving means receives the radio wave from the positioning satellite which is repeatedly modulated by the navigation message data consisting of a plurality of bits, and the carrier signal reproducing means includes the carrier signal included in the received signal. To play. The phase angle integration means integrates the phase angles of the reproduced carrier signals, and the navigation message data demodulation means demodulates the navigation message data. Then, the bit data length determination means determines whether or not each bit data forming the demodulated navigation message data continues for a predetermined time of one bit. If a certain bit of the data constituting the demodulated navigation message data does not continue for a predetermined one bit time, it is considered that a cycle slip has occurred at the time when the phase angle of the reproduced carrier signal is integrated. be able to.

In the satellite navigation receiving apparatus according to the sixth aspect, the code pattern extracting means extracts a code pattern repeatedly appearing in the demodulated navigation message data, and the code pattern appearance determining means predetermines the extracted code pattern. It is determined whether or not it appears in a cycle. If the code pattern appearing in the demodulated navigation message data differs from the predetermined cycle, it can be considered that a cycle slip has occurred at that time.

In the satellite navigation receiving apparatus according to the seventh aspect, the orthogonal component extracting means extracts the orthogonal component of the carrier frequency of the received signal, and the absolute value extracting means obtains the absolute value of the orthogonal signal from which the carrier component is removed. The moving average value extracting means finds a moving average value of the absolute value in a fixed time, and the comparing means compares the absolute value and the moving average value.

FIG. 3 is a block diagram showing an example of the configuration of the main part of the satellite navigation receiving apparatus according to the seventh aspect. In FIG. 3, the IQ separation circuit 2 corresponds to the orthogonal component extraction means, the absolute value circuit 21 corresponds to the absolute value extraction means, and the moving average circuit 22.
Corresponds to the moving average value extraction means, and the comparator 24 corresponds to the comparison means. The signal received by the receiving circuit 1 is separated into the in-phase component (I signal) and the quadrature component (Q signal) by the IQ separation circuit 2, the carrier component is removed by the carrier component removal circuit 3, and the C / A code synchronization circuit 4 Synchronizes with the C / A code. The phase error extracting circuit 5, the loop filter 6 and the carrier signal reproducing circuit 7 constitute a phase locked loop circuit which is synchronized with the carrier phase. The integrating circuit 20 integrates the quadrature component from which the carrier component has been removed for a certain period of time, and the absolute value circuit 21 obtains the absolute value. The output level of the absolute value circuit 21 is 0 in the normal state where the carrier phase is completely synchronized, but if a cycle slip occurs, a quadrature component appears and the output level of the absolute value circuit 21 rises.

Since the reference level circuit 23 sets the reference level from the average value of the orthogonal components in the normal state, the presence or absence of cycle slip can be detected by the comparison result of the comparator 24.

According to another aspect of the present invention, there is provided a mobile positioning system, which comprises a reference station installed at a known fixed point and a mobile station installed on a mobile body, and the receiving means of the reference station receives radio waves from a positioning satellite, The signal reproducing means reproduces the carrier signal included in the received signal, the phase angle integrating means integrates the phase angle of the reproduced carrier signal, and the phase angle integrated value data transmitting means wirelessly transmits the calculated phase angle adjustment value. Send. The receiving means on the mobile station side receives the radio wave from the positioning satellite at a plurality of points on the moving body which have a relatively fixed positional relationship, and the carrier signal reproducing means reproduces the carrier signal included in each received signal. The phase angle integrating means integrates the phase angle of each carrier signal. The phase angle integrated value data receiving means receives the phase angle integrated value data transmitted from the reference station, and the relative position vector integrating means receives and obtains the received phase angle integrated value and a plurality of points on the moving body. A relative position vector of a plurality of receiving points on the moving body with respect to the reference point is obtained from the integrated value of the phase angle, the position information of the reference point, and the position information of the positioning satellite. The relative position vector comparison means compares the obtained relative position vector between the receiving points on the moving body with a known relative position vector between the receiving points on the moving body. Then, the cycle slip occurrence point determination means determines the reception point where the cycle slip has occurred at the time of integrating the phase angle of the reproduced carrier signal from the comparison result.

FIG. 4 shows the relationship between the positions of the reference station and mobile station, and the relative position vector. In FIG. 4, REF is a reference station MRX1, MRX2, M installed at a known fixed point.
RX3 are three receiving points on the mobile station side, which are arranged on the same ship in a relatively fixed positional relationship. Reference station R
The relative position vectors of the reception points MRX1, MRX2, MRX3 with respect to the EF are obtained as P1, P2, P3. Relative position vector P12 between each receiving point on the moving body,
P13, P23 are known values because each receiving point is fixed on the moving body and the three-dimensional azimuth can be measured by a gyro compass or the like. From the relative position vectors P1 ', P2', P3 'of each reception point to the reference point obtained by reception at the reference station REF and a plurality of points on the mobile station, relative position vectors P12', P13 ', P23' between the reception points. Are required respectively. These relative position vectors are compared with known relative position vectors P12, P13, P23, respectively. If P12 'and P13' are abnormal values significantly different from P12 and P13 and P23 'is a normal value substantially equal to P23, it can be determined that a cycle slip has occurred at the time of reception by MRX1. If P12 'and P23' are P
12, P23 'is an abnormal value that is significantly different from P23.
If the normal value is approximately equal to 13, it can be determined that a cycle slip has occurred at the time of reception by MRX2. Similarly, if P13 'and P23' are abnormal values that are significantly different from P13 and P23, and P12 'is a normal value that is substantially equal to P12, it can be determined that a cycle slip has occurred during reception by the MRX3.

In the mobile body positioning system according to claim 9, the cycle slip correcting means corrects the phase slip integrated value by the reception at the reception point where the cycle slip is judged by the cycle slip presence / absence judging means for the cycle slip. I do. For example, in FIG. 4, P12 'and P1
3'is an abnormal value that is significantly different from P12 and P13, and P2
If 3'is a normal value almost equal to P23, MRX1
It is possible to determine that a cycle slip has occurred at the time of reception at, but in this case, P12 'and P13' are P12 and P1.
The phase angle integrated value data in MRX1 is added or subtracted by an integral multiple of the phase angle 360 ° in the direction of becoming equal to 3, and the correction is performed. If P12 'and P23' are abnormal values significantly different from P12 and P23 and P13 'is a normal value substantially equal to P13, it can be determined that a cycle slip has occurred at the time of reception by the MRX2. , In this case P1
2 ', P23' is equal to P12, P23 in the direction M
The phase angle integrated value data in RX2 is corrected by adding or subtracting an integral multiple of the phase angle of 360 °.

[0036]

FIG. 5 is a block diagram showing the configuration of a GPS receiver according to an embodiment of the present invention.

In FIG. 5, 30 is a receiving antenna,
The high frequency amplifier circuit 31 amplifies the received signal at a high frequency, and the mixer 33 mixes it with the signal from the local oscillator 32 to convert it into an intermediate frequency signal. The intermediate frequency amplifier circuit 34 amplifies this. The AD converter 35 samples the intermediate frequency signal and converts it into digital data. IQ separation circuit 36
Separates the AD-converted data into an in-phase component (I signal) and a quadrature component (Q signal). Carrier component removal circuit 3
7 removes the carrier component from the value given from the IQ separation circuit 36 based on the signal given from the numerical control oscillation circuit 47, and outputs the I signal and the Q signal from which the carrier component has been removed to the EPL separation circuits 38 and 39, respectively. .

The EPL separation circuits 38 and 39 output the output timings of the I signal and the Q signal from which the carrier component has been removed by 0.5 chip (1/2 of the 1-bit length of the C / A code).
Advanced signal (hereinafter referred to as E (EARLY) signal),
0 chip (hereinafter referred to as P (PUNCTUAL) signal)
And a signal delayed by 0.5 chip (hereinafter referred to as L (LATE) signal) and output to the multipliers 40 and 41, respectively. The multipliers 40 and 41 respectively multiply the E, P and L signals by the C / A code output from the C / A code generation circuit 45. Accumulators 42, 43
The output values of the E, P and L signals of the multipliers 40 and 41 are integrated (counted up) for a certain period of time. The C / A code generation circuit 45 and the multiplier 40 and the integrator 42 constitute an I signal correlator, and the C / A code generation circuit 4
5 and the multiplier 41 and the integrator 43 form a correlator for the Q signal. The C / A code generation circuit 45 generates a C / A code of a type and a phase determined according to the data in the setting register 44. The reference oscillator 48 generates a reference frequency signal and supplies it to a numerically controlled oscillator circuit (NCO) 47 and a clock circuit 49. The numerically controlled oscillation circuit 47 gives a frequency signal based on the data set in the setting register 46 to the carrier component removal circuit 37. The temperature sensor 50 detects the temperature of the reference oscillator 48. The speed sensor 52 detects the speed (three-dimensional direction and size) associated with the movement of the moving body provided with this GPS receiver. The transmission control interface 59 controls data transmission with an external device. For example, when this GPS receiver is used as a reference station for interferometric positioning, data transmission control is performed with the data transmitter. The CPU 56 executes a program written in advance in the ROM 57 to perform various controls described later. RA
M58 is used as a working area for temporary storage of various data and arithmetic processing. The CPU 56 uses the temperature sensor 50 to generate the reference oscillator 48 via the interface 51.
The temperature data of the moving body is read, and the speed data of the moving body is read through the interface 53. Further, the CPU 56 reads the data of the integrators 42 and 43 at a constant cycle, performs the calculation for the C / A code and the carrier phase (the calculation of the loop filter) from the data, and sets the setting register 44,
By setting the data in 46, the C / A code phase and the carrier phase are synchronized with each other, and the data set in the setting register 46 is integrated at fixed time intervals to obtain the phase angle integrated value data of the carrier phase.

Next, claim 1 of the CPU 56 shown in FIG.
The operation corresponding to 4 is shown as a flowchart in FIG. First, the speed of the moving body is read by the speed sensor 52, and the temperature of the reference oscillator 48 is read by the temperature sensor 50 (n1 → n2). Then, it is determined whether or not the signal is in a suspended state (n3). Specifically, if the value of the integrated value of the P signal of the integrator 42 shown in FIG. 5 does not reach the predetermined reference value, it is considered that the signal is interrupted, and if it is the reference value or more, the C / A code It is assumed that the phase and carrier phase are kept in synchronism. If the signal is not in the interrupted state, the phase error PE is first read (n4). This is the EPL of the in-phase component obtained by the integrators 42 and 43 shown in FIG.
It is obtained from the integrated value of each of the signal and the EPL signal of the orthogonal component. Subsequently, the phase error is integrated to calculate the frequency change dimension data VE, and the moving average value VE ′ of the frequency change over a fixed time is obtained and updated (n5 → n).
6). Then, the moving speed of the moving body and the temperature of the reference oscillator read in steps n1 and n2 are stored (n7 → n).
8). After that, the frequency change amount VE is integrated to obtain frequency-dimensional data FE, and the phase error PE and the frequency change amount VE are calculated.
And the frequency FE have constant coefficients k1, k2, k, respectively.
Control data for the numerically controlled oscillator circuit (NCO) is calculated by weighting and adding 3 to each other, and this is set in the setting register 46 shown in FIG. 5 (n9 →
n10 → n11). If the signal is interrupted, the phase error PE is first set to 0 (n12). Then, with respect to the speed of the moving body and the temperature of the reference oscillator stored when the signal is not in the suspended state, the variation amount ΔVE of the frequency change is predicted from the changes in the speed of the moving body and the temperature of the reference oscillator read this time (n13). ). Then, the variation amount ΔVE is added to the moving average value VE ′ of the frequency variation to correct the frequency variation data (n14). After that, the frequency change data is integrated to calculate frequency-dimensional data FE, and similarly, control data for the numerically controlled oscillator circuit (NCO) is calculated and output to the setting register 46 (n9 → n10 → n11). ). The process shown in FIG. 6 is repeated at regular intervals.

Next, the principle of performing the interference positioning using the GPS receiver shown in FIG. 5 will be described with reference to FIG. Here, it is considered that the receiver A is the receiver of the reference station and the receiver B is the receiver of the mobile station. When the plane including the receiver A, the receiver B and the GPS satellite is a vertical plane and the elevation angle of the satellite is θ, the radio waves received by the receiver A and the receiver B are rcos (θ) minutes. There is a phase difference. On the contrary, from this phase difference, the receiver A
The base line length r between the receiver and the receiver B is known. Then, the base line vector (three-dimensional direction and distance) of the mobile station with respect to the reference station is obtained by obtaining the phase difference between the radio waves of the satellites transmitted from different positions. If the L1 band of the GPS positioning radio signal is used, one wavelength is about 19 cm, so that it is possible to detect a change of several centimeters shorter than one wavelength. However, if the signal is momentarily interrupted due to multipath of radio waves when integrating the phase angle of the carrier signal, slip (cycle slip) of an integral multiple of 360 ° occurs. A method of detecting the occurrence of such a cycle slip during observation will be described below.

FIG. 8 shows the CPU 56 shown in FIG.
6 is a flowchart showing an operation corresponding to. This Figure 8
The process shown in is executed at the bit start timing of the navigation message. Bit rate of navigation message is 50bp
s is 180 ° phase-modulated, and the main frame consists of data of 1500 bits for 30 seconds.
It is divided into 5 subframes of 300 bits each for 6 seconds. Therefore, one bit lasts 20 msec. Figure 8
In the example shown in (1), the navigation message signal is read at a cycle of 1 msec, and this is read 20 times (for 20 msec) (n20 → n21 → n22). Then, it is determined whether or not all 20 pieces of sampling data have the same polarity (n23). Since the navigation data is phase-modulated by 180 °, if there is a bit change within 20 samplings, the polarity will change at that point.
From this, it can be detected that a cycle slip has occurred.

Next, claim 6 of the CPU 56 shown in FIG.
FIG. 9 is a flowchart showing a processing procedure corresponding to. This processing is executed from the start timing of the navigation message. First, sampling data for 1 bit of the navigation message is extracted (n30). Specifically, sampling is performed 20 times every 1 msec during 20 msec which is one bit, and a bit "1" or "0" is determined from the polarities of 20 data by majority (n3).
1). This process is performed for one subframe (300 bits) (n32 → n30 ...). Then this one
The 8-bit (preamble) bit pattern of the synchronization pattern that also serves as telemetry, which is abbreviated as TLM added to the beginning of the subframe, is determined as a predetermined bit pattern "10001011" or its inversion pattern. To do. If this does not match, it can be considered that a cycle slip has occurred.

Next, claim 7 of the CPU 56 shown in FIG.
FIG. 10 shows a processing procedure corresponding to the above as a flowchart. First, the orthogonal component data Q is read (n40). Specifically, the integrated value of the P signal of the integrator 43 shown in FIG. 5 is read. Then, the moving average value QM of the absolute values is calculated (n41). Then, a value QR that is higher than the QM by a certain ratio is determined as a reference level (n42). Then, the magnitude of the quadrature component Q and the reference level QR are compared (n43).
In the normal state where no cycle slip occurs, the quadrature component Q is smaller than the reference level QR, but when the cycle slip occurs, the quadrature component Q greatly exceeds the reference level QR. Can be determined.

Next, FIG. 11 is a block diagram showing the configuration of a mobile body positioning system corresponding to claims 8 and 9.
In FIG. 11, reference numeral 60 is a reference station fixedly arranged at a known point on land, and is composed of a GPS receiver 61 and a data transmitter 62. A mobile station 70 is installed on the ship and is composed of three GPS receivers 71, 72, 73 and a data receiver 74. The GPS receiver 61 of the fixed station receives radio waves from a plurality of GPS satellites (81, 82, etc.) and obtains a phase angle integrated value thereof. The data transmitter 62 wirelessly transmits the phase angle integrated value for each satellite together with time data. The three GPS receivers 71, 72, 73 on the mobile station side are arranged at the positions of MRX1, MRX2, MRX3 shown in FIG. 4, respectively, and receive the radio waves from each satellite to obtain the integrated value of the phase angle. The data receiver 74 on the mobile station side is
The phase angle integrated value for each satellite obtained by the PS receiver is collected together with the time data, the data transmitted from the data transmitter 62 of the reference station is received, and the GPS receivers 71 and 72 for the reference station by the interferometric positioning method are received. , 73 relative position vector is obtained. With this configuration, while the mobile station 70 is stopped at the reference calibration point which is a known point, each GP of the mobile station is
If the absolute position of the S receiver is set, the integer value bias of the integrated phase angle value is determined, and the integrated phase angle value is obtained while continuing to receive radio waves from the satellite starting from the reference calibration point, the It is possible to perform so-called kinematic GPS positioning in which the position of each point moved by the station is sequentially positioned as a relative position with respect to the reference station.

The GPS receivers 61, 71, shown in FIG.
The configurations of 72 and 73 are basically the same as those shown in FIG. 5, but the speed sensor 52 shown in FIG. 5 is not necessary for the GPS receiver 61 on the reference station side.

The configuration of the data transmitter 62 shown in FIG. 11 is shown in FIG. 12 as a block diagram. In FIG. 12, the CPU
90 executes a program written in advance in the ROM 91.

The RAM 92 is used as a working area for temporarily storing and processing transmission data when executing the program. The transmission control interface 93 is GP
Transmission control of various data is performed with the S receiver 61. C
The PU 90 transmits G via the transmission control interface 93.
Various data such as satellite identification information, phase angle integrated value, and time data are read from the PS receiver 61. The transmission control interface 94 transmits a signal for wireless transmission,
The data transmission circuit 95 wirelessly transmits the signal.

The data receiver 7 on the mobile station side shown in FIG.
FIG. 13 shows the configuration of No. 4 as a block diagram. In FIG. 13, the CPU 100 executes a program previously written in the ROM 101. The RAM 102 is used as a working area for temporarily storing and processing transmission data when executing the program. Transmission control interface 1
Reference numeral 03 controls transmission of various data with the three GPS receivers 71, 72, 73. The CPU 100 reads various kinds of data such as satellite identification information, phase angle integrated value and time data from each GPS receiver via the transmission control interface 103. The data receiving circuit 105 receives a signal wirelessly transmitted from the data transmitter of the reference station, and the CPU 100 reads the received signal via the transmission control interface 104. The gyro compass 106 detects the three-dimensional azimuth of the moving body. The CPU obtains the relative position vector between the three GPS receivers 71, 72, 73 from this three-dimensional azimuth.

Next, the processing procedure of the CPU of the data receiver on the mobile station side shown in FIG.
It shows in FIG. First, various data transmitted from the data transmitter 62 of the reference station is read. (Various data transmitted from the data transmitter 62 of the reference station is sequentially stored every time it is received, and the stored data is read.) (N
50) Data from each GPS receiver 71, 72, 73 (satellite identification information, phase angle integrated value, time information, etc.)
Is read (n51). Then, based on these data, as shown in FIG. 4, each GPS of the mobile station relative to the reference station
The relative position vectors P1, P2 and P3 of the receiver are calculated (n52). Next, the three-dimensional azimuth is read from the gyro compass, and the three-dimensional azimuth and GPS receivers 71, 72,
The relative position vectors P12, P13, P23 between the receivers are calculated based on the relative positions of the reception points 73 (n53 → n54). Then, as shown in FIG.
Relative position vectors P12, P1 between the receivers on the mobile station side
3, P23 and relative position vector P12 ', P by measurement
By comparing 13 'and P23' respectively, the receiving point where the cycle slip has occurred is determined. That is, as shown in FIG. 15, first, flags F12 and F1 for determination are used.
3 and F23 are respectively reset, and the relative position vector P
The normality / abnormality of P12 'is determined depending on whether the difference between P12' and P12 'is within a predetermined value (n56 → n).
57 → n58). If it is abnormal, the flag F12 is set (n59). Similarly, relative position vectors P13 and P1
The difference from 3'is determined to determine whether P13 'is normal (n60 → n61). If abnormal, flag F13
Is set (n62). Furthermore, the relative position vector P2
The difference between 3 and P23 'is obtained, and the normality / abnormality of P23' is determined (n63 → n64). If it is abnormal, the flag F23 is set (n65). Then, as shown in FIG. 16, if both flags F12 and F13 are set, it is considered that a cycle slip has occurred in the phase angle integrated value obtained by the GPS receiver 71 arranged at the reception point MRX1, and the correction is made. Perform (n66 → n67 → n68 → n6
9). If the flags F12 and F23 are in the set state, it is considered that a cycle slip has occurred in the phase angle integrated value obtained by the GPS receiver 72 arranged at the reception point MRX2, and the correction is performed (n70 → n71). Also flag F
If 13, F23 are in the set state, it is considered that a cycle slip has occurred in the phase angle integrated value obtained by the GPS receiver 73 arranged at the reception point MRX3, and the correction is performed (n72 → n73 → n74).

If all of the flags F12, F13, F23 are in the reset state, it is considered that the cycle slip has not occurred in any of them. Flags F12, F13, F
When only one of 23 is set, it is regarded as an abnormal state and abnormal processing is performed (n77, n7).
8, n79, n80). The cycle slip is corrected by adding / subtracting the phase angle integrated value that is an integral multiple of 360 ° in the direction in which the relative position vector between the reception points becomes equal to the known relative position vector. After the cycle slip is not generated or after the cycle slip is corrected, the ship motions such as the heading, rolling and pitch are measured from the relative position vector between the GPS receivers (n7).
6).

[0051]

According to the satellite navigation receiving apparatus of the present invention, the carrier phase can be estimated and tracked during the interruption of the received signal even if the received signal is interrupted. The carrier phase tracking can be continued immediately after the return, and the positioning can be continued even when the reception conditions are deteriorated such as the occurrence of multipath. Further, according to the satellite navigation receiver of claims 5, 6 and 7, it is possible to immediately know at the time of observation whether or not a cycle slip has occurred at the time of integrating the phase angle of the carrier signal, and a measure to be taken when the cycle slip has occurred Will be easier. According to the mobile positioning system of claims 8 and 9, it is possible to determine that a cycle slip has occurred on the side of the mobile station and to easily perform the automatic correction without stopping and recalibrating the mobile station. Like

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a main part of a satellite navigation receiving device according to claims 1 and 2 of the present invention.

FIG. 2 is a block diagram showing a configuration example of a loop filter 6 shown in FIG.

FIG. 3 is a block diagram showing a configuration example of a main part of a satellite navigation receiving device according to claim 7 of the present invention.

FIG. 4 is a diagram showing the relationship between the position and relative position vector of the reference station and the mobile station in the mobile positioning system according to claim 8 of the present invention.

FIG. 5 is a block diagram showing a configuration of a GPS receiver that is an embodiment of the present invention.

6 are claims 1, 2, 3, 4 of the CPU 56 shown in FIG.
It is a flowchart which shows the process procedure corresponding to.

FIG. 7 is a diagram showing a principle of an interferometric positioning method.

8 is a flowchart showing a processing procedure corresponding to claim 5 of the CPU 56 shown in FIG.

9 is a flowchart showing a processing procedure corresponding to claim 6 of the CPU 56 shown in FIG.

10 is a flowchart showing a processing procedure corresponding to claim 7 of the CPU 56 shown in FIG.

FIG. 11 is a block diagram showing a configuration of a mobile body positioning system corresponding to claims 8 and 9.

12 is a block diagram showing a configuration of a data transmitter 62 shown in FIG.

13 is a block diagram showing a configuration of a data receiver 74 shown in FIG.

14 is a flowchart showing a processing procedure of a CPU in the data receiver shown in FIG.

15 is a flowchart showing a processing procedure of a CPU in the data receiver shown in FIG.

16 is a flowchart showing a processing procedure of a CPU in the data receiver shown in FIG.

[Explanation of symbols]

 REF-reference station MRX1, MRX2, MRX3-reception point of mobile station 60-reference station 70-mobile station 81,82-GPS satellite

Front page continued (72) Inventor Harumi Fukuda 1-16, Taniyama Port, Kagoshima City Kagoshima Prefecture Kagoshima Port Construction Office, 4th Port Construction Bureau, Ministry of Transportation (72) Inventor Kenji Izono 9 Ashihara-cho, Nishinomiya-shi, Hyogo Prefecture No.52 Furuno Electric Co., Ltd.

Claims (9)

[Claims] 1. A receiving means for receiving radio waves from a positioning satellite that has been spectrum spread by a pseudo noise code, a code synchronizing means for synchronizing with a pseudo noise code included in the received signal, and a carrier included in the received signal. Carrier signal reproducing means for reproducing a signal, phase error extracting means for obtaining a phase error by comparing the phase of the reproduced carrier signal reproduced by the carrier signal reproducing means with the received signal, and the carrier of the received signal from the phase error. In a satellite navigation receiver equipped with loop filter means for determining the frequency of the reproduced carrier signal synchronized with the phase, the signal intensity of the spectrum despread by code synchronization is compared with the reference intensity, and when the intensity is less than the reference intensity, The phase error for the loop filter is set to 0, and the intensity of the spectrum despread signal is the reference intensity. When it is higher, the satellite navigation receiver, characterized in that a phase error switching means for the phase error of the phase error obtained in the phase error extracting means for said loop filter. 2. A phase error data integration means for sequentially integrating phase error data to obtain frequency change data, an average frequency change data storage means for storing a moving average value of the frequency change data, and a frequency change data. Frequency change data data accumulating means for accumulating data to obtain frequency data,
Frequency control data calculation means for obtaining frequency control data of the reproduced carrier signal by weighting and adding the phase error data, the frequency change data, and the frequency data respectively, and the phase error switching means switches the phase error to zero. 2. The satellite navigation receiving apparatus according to claim 1, wherein the loop filter means is composed of frequency change data switching means for setting the content of the frequency change data storage means as frequency change data. 3. A speed measuring means for measuring a speed of a receiving device, a frequency change amount fluctuation amount predicting means for predicting a fluctuation amount of the frequency change amount from the speed change obtained by the speed measuring means, and the average frequency. 3. The satellite navigation receiving apparatus according to claim 2, further comprising frequency change data correction means for correcting the change amount of the frequency change with respect to the average frequency change data obtained by the change data storage means. 4. The reference oscillator for measuring the temperature of the reference oscillator, wherein the carrier signal reproducing means comprises a reference oscillator for generating a reference frequency signal and a frequency variable oscillator circuit for generating a carrier signal with the reference frequency signal as a reference. A temperature measuring means, a frequency change variation predicting means for predicting a variation of the frequency change data from a change in temperature measured by the reference oscillator temperature measuring means, and an average frequency calculated by the average frequency change data storing means. 3. The satellite navigation receiving apparatus according to claim 2, further comprising frequency change data correction means for correcting the change amount of the frequency change with respect to the change data. 5. A receiving means for receiving a radio wave from a positioning satellite that is repeatedly modulated by navigation message data composed of a plurality of bits, a carrier signal reproducing means for reproducing a carrier signal included in the received signal, and a reproduced carrier. In a satellite navigation receiver equipped with a phase angle accumulating means for accumulating phase angles of signals and a navigation message data demodulating means for demodulating navigation message data, each bit data constituting demodulated navigation message data is predetermined. Further, there is provided bit data length determination means for determining whether or not the time is continuous for one bit, and the presence or absence of cycle slip occurring at the time of integrating the phase angle of the reproduced carrier signal is determined by the result of this bit data length determination means. A satellite navigation receiver characterized by detecting. 6. A receiving means for receiving a radio wave from a positioning satellite that is repeatedly modulated by navigation message data consisting of a plurality of bits, a carrier signal reproducing means for reproducing a carrier signal included in the received signal, and a reproduced carrier. A code pattern for extracting a code pattern repeatedly appearing in the demodulated navigation message data in a satellite navigation receiving device equipped with a phase angle integrating means for integrating the phase angle of the signal and a navigation message data demodulating means for demodulating the navigation message data. An extraction means and a code pattern appearance determination means for determining whether or not the extracted code pattern appears in a predetermined cycle are provided, and the result of the code pattern appearance determination means determines the phase angle of the reproduction carrier signal. Characterized by detecting the presence or absence of cycle slips that occur during integration Satellite navigation receiver apparatus that. 7. Receiving means for receiving radio waves from a positioning satellite, carrier signal reproducing means for reproducing a carrier signal included in the received signal, and phase angle integrating means for integrating the phase angle of the reproduced carrier signal. In the satellite navigation receiver including, an orthogonal component extracting means for extracting an orthogonal component of the carrier frequency of the received signal, an absolute value extracting means for obtaining an absolute value of the orthogonal component from which the carrier component has been removed by the carrier component removing means, A moving average value extracting means for obtaining a moving average value of the absolute value in a fixed time period, a comparing means for comparing the absolute value with a reference value obtained from the moving average value, and a comparing result of the comparing means. A satellite navigation receiving apparatus, characterized in that the presence or absence of a cycle slip occurring when the phase angles of the reproduced carrier signals are integrated is detected. 8. Receiving means for receiving radio waves from a positioning satellite, carrier signal reproducing means for reproducing a carrier signal included in the received signal, and phase angle integrated value data obtained by integrating the phase angle of the reproduced carrier signal. The base station installed at a known fixed point, consisting of the phase angle integrating means for obtaining the phase angle integrated value data and the phase angle integrated value data transmitting means for wirelessly transmitting the phase angle integrated value data, and a relatively constant positional relationship on the moving body. The receiving means for receiving the radio waves from the positioning satellites at a plurality of points, the carrier signal reproducing means for reproducing the carrier signal included in each received signal, and the phase angle obtained by integrating the phase angle of each reproduced carrier signal. Phase angle integrated value data obtaining means for obtaining the angle integrated value data, phase angle integrated value data receiving means for receiving the phase angle integrated value data transmitted from the reference station, and the phase angle integrated value data receiver. From the received phase angle integrated value data, the phase angle integrated value data obtained by receiving at the plurality of points, the position information of the reference point, and the position information of the positioning satellite, and a plurality of reception points on the moving body with respect to the reference point. Relative position vector calculating means for obtaining the relative position vector of, and the relative position vector between each receiving point on the moving body obtained by this relative position vector calculating means and the known relative position vector between each receiving point on the moving body On the moving body, which comprises a relative position vector comparison means for making a comparison and a cycle slip generation point determination means for determining a reception point where a cycle slip has occurred at the time of integrating the phase angle of the reproduced carrier signal from the comparison result. A mobile positioning system consisting of a mobile station provided in. 9. The cycle slip correcting means for correcting the phase slip integrated value by the reception at the reception point where the cycle slip has occurred, which is judged by the cycle slip occurrence point judging means, is further provided. The mobile positioning system described.