JP2009014669A - Apparatus and method for time correction and time measuring apparatus with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a time correction apparatus and others capable of acquiring time information from position information satellites such as GPS satellites while lowering a maximum value of electric power to be consumed. <P>SOLUTION: The time correction apparatus 10 comprises a reception part 20 and others for receiving satellite signals transmitted from the position information satellites 15; a satellite signal computation part 36 for computing satellite signals received at the reception part and acquiring at least satellite time information 46; a time measuring part 23 having self-time information; and a time information correction part 38 for correcting the self-time information on the basis of the satellite time information. The reception part comprises both a frequency processing part 20 for converting and processing the frequency of the received satellite signals and a demodulation processing part 21 for demodulating and processing satellite signals converted and processed at the frequency processing part. The frequency processing part; the demodulation processing part; and the satellite signal computation part are selectively operated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a time adjustment device that performs time adjustment based on a signal from a position information satellite such as a GPS satellite, a time measuring device with a time adjustment device, and a time adjustment method.

In a GPS (Global Positioning System) system, which is a system for positioning its own position, a GPS satellite having an orbit around the earth is used, and this GPS satellite is provided with an atomic clock. For this reason, GPS satellites have extremely accurate time information (GPS time).
In order to obtain the GPS satellite time information, the receiver side that receives the signal from the GPS satellite shows TOW (Time of Week, GPS time, weekly from the beginning of the week) of the signals from the GPS satellite. Information in seconds)) (for example, Patent Document 1).
And in order to receive this time information, it is necessary to receive the signal of the GPS satellite orbiting the earth, take a correlation etc., and calculate after that, and acquire time data.
Specifically, a GPS signal is received by an antenna, the signal is converted to an intermediate frequency or the like by RF (Radio Frequency), and then a GPS signal is extracted by taking a correlation or the like in a baseband part. The GPS signal is calculated by the calculation unit to extract time information.
Japanese Patent Laid-Open No. 10-10251 (summary, etc.)

Therefore, in order to actually acquire time information after receiving a GPS satellite, it is necessary to simultaneously operate the antenna unit, the RF unit, the baseband unit, the arithmetic unit, etc., and the peak of power consumption on the receiver side Becomes higher, for example, about several tens of mA.
In order to secure such peak power, it is necessary to increase the battery size. However, since a time measuring device such as a watch is required to be downsized, the battery size cannot be increased. There has been a problem that the system of the equipment is down.

  Therefore, the present invention provides a time adjustment device, a time measuring device with a time adjustment device, and a time adjustment method capable of acquiring time information from a position information satellite such as a GPS satellite while suppressing the maximum value of power consumption. For the purpose.

  According to the above object, the present invention provides a receiving unit that receives a satellite signal transmitted from a position information satellite, and a satellite signal that obtains at least satellite time information by calculating the satellite signal received by the receiving unit. A calculation unit; a clock unit having self-time information; and a time information correction unit that corrects the self-time information based on the satellite time information. The reception unit calculates a frequency of the received satellite signal. A frequency processing unit for conversion processing, and a demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit, the frequency processing unit, the demodulation processing unit or the satellite signal calculation unit, This is achieved by a time adjustment device that is configured to selectively operate.

According to the above configuration, since the frequency processing unit, the demodulation processing unit, or the satellite signal calculation unit is configured to selectively operate, an increase in the maximum power value (peak power value) of the timing device can be suppressed. it can.
In addition, the satellite signal calculation unit performs an arithmetic operation based on the frequency converted by the frequency processing unit and the demodulated satellite signal obtained by demodulating the signal of the frequency converted by the demodulation processing unit. Information can be acquired. Further, the self-time information can be corrected based on the satellite time information.
Thus, in the configuration of the present invention, when the RF unit, which is a frequency processing unit that receives satellite signals and performs frequency conversion processing, is operating, for example, another demodulation processing unit (for example, BB (baseband)) Part) and the satellite signal calculation part do not operate. After that, when the demodulation processing unit operates, the frequency processing unit and the satellite signal calculation unit do not operate. Further, when the satellite signal calculation unit operates, the frequency processing unit and the demodulation processing unit do not operate.
For this reason, time information can be acquired from position information satellites, such as a GPS satellite, suppressing the maximum value of the electric power consumed.

  Preferably, the time correction apparatus includes a satellite signal storage unit that stores the satellite signals processed by the frequency processing unit and the demodulation processing unit.

According to the configuration, since the satellite signal storage unit that stores the satellite signal processed by the frequency processing unit and the demodulation processing unit is included, the demodulation processing unit stops operating by referring to the satellite signal storage unit. Demodulation processing can be performed using the satellite signal processed by the frequency processing unit.
Further, the satellite signal calculation unit can perform calculation processing by using the satellite signal processed by the demodulation processing unit that has stopped operating by referring to the satellite signal storage unit.

  Preferably, the time information correction unit includes a counter unit that acquires reception unit timing information that is operation-related time of the reception unit and / or satellite signal calculation timing information that is operation-related time of the satellite signal calculation unit, The time correction device is configured to correct the self-time information based on correction timing information calculated based on the reception unit timing information and / or the satellite signal calculation timing information.

According to the said structure, a time information correction part becomes a structure which correct | amends the said own time information based on the correction timing information calculated based on receiving part timing information and / or satellite signal calculation timing information.
Usually, in order to obtain the correction timing information, for example, the time correction device needs to actually receive the satellite signal and follow the received satellite signal.
However, in the present invention, the correction timing information cannot be obtained directly from the received signal because the receiving unit does not receive the satellite signal while the satellite signal calculation unit operates.
Therefore, in the present invention, the time during which the satellite signal calculation unit is operating is measured by the counter unit, and the correction timing information is determined in consideration of this measurement time, etc., so that the reception unit continues to receive satellite signals. The correction timing information can be calculated with the same accuracy as.

  Preferably, the satellite signal includes propagation time delay information which is a time required for arrival of the satellite signal of the position information satellite.

According to the above configuration, the satellite signal includes propagation delay time information that is the time required for the satellite signal to reach the position information satellite.
For this reason, it is possible to obtain extremely accurate correction timing information in consideration of this propagation delay time information.

  Preferably, the reception unit timing information includes satellite signal reception time information which is a time at which the reception unit receives a satellite signal of the position information satellite, and the satellite signal reception time information includes the satellite time information and The time correction apparatus is characterized in that it is the minimum necessary time information for acquiring the correction timing information.

  According to the above configuration, the satellite signal reception time information is the minimum necessary time information for acquiring the satellite time information and the correction timing information. Time information and correction timing information can be calculated.

  Preferably, the counter section is configured to operate based on a high-accuracy oscillator.

  According to the above configuration, since the counter unit is configured to operate based on the high precision oscillator, it is possible to obtain correction timing information and the like with high accuracy.

  Preferably, the satellite signal includes subframe number information, and includes a target subframe number including week number information of GPS time and / or UTC (Universal Time Coordinate) parameter information from the subframe number information. The time correction device includes a subframe number acquisition unit that acquires information, and is configured to receive the target subframe of the satellite signal based on the target subframe number information.

According to the above configuration, the subframe number acquisition unit acquires target subframe number information including week number information of GPS time and / or UTC parameter information from the subframe number information, and based on the target subframe number information, The target subframe of the satellite signal is received.
For this reason, for example, even when GPS time week number information cannot be acquired by receiving a single satellite signal, a subframe that accurately stores GPS time week number information is received based on target subframe number information. As a result, GPS number week number information and the like can be acquired.

  Preferably, the satellite signal includes satellite number information, Doppler frequency information and C / A code phase information of the position information satellite, and the received satellite number information, Doppler frequency information and C / A code of the position information satellite. A time correction apparatus having a captureable satellite information storage unit for storing code phase information.

  According to the above configuration, since it has the captureable satellite information storage unit that stores the satellite number information, the Doppler frequency information, and the C / A code phase information of the received position information satellite, by using this satellite number information, etc. It becomes easy to acquire the position information satellite.

  Preferably, the time correction device is characterized in that the satellite signal reception time information is a C / A code length or a message 1 bit length.

According to the said structure, satellite signal reception time information is C / A code length thru | or message 1 bit length.
Therefore, it is possible to provide position information satellite information that can be received at the time or the like by receiving a satellite signal for a very short time (1 msec (C / A code length), 20 msec (message 1 bit length)). .

  Preferably, the satellite signal is received a plurality of times from the same position information satellite, and has a consistency determination unit that determines the consistency of the plurality of satellite time information acquired by the reception of the plurality of times. It is the time correction apparatus characterized by this.

  According to the said structure, it has the structure which receives a satellite signal in multiple times from the said said positional information satellite, and has a consistency judgment part which judges the consistency of several satellite time information acquired by multiple times reception. . For this reason, more accurate time information can be acquired.

  Preferably, the satellite signal is received from a plurality of the position information satellites, and a different satellite consistency determination unit that determines the consistency of the plurality of time information acquired from the plurality of the position information satellites. It is the time correction apparatus characterized by having.

  According to the above configuration, the satellite signals are received from the plurality of position information satellites, and the different satellite consistency determination unit that determines the consistency of the plurality of time information acquired from the plurality of position information satellites is provided. . For this reason, more accurate time information can be acquired.

  According to the present invention, there is provided a receiving unit that receives a satellite signal transmitted from a position information satellite, and a satellite signal that obtains at least satellite time information by calculating the satellite signal received by the receiving unit. A calculation unit; a clock unit having self-time information; and a time information correction unit that corrects the self-time information based on the satellite time information. The reception unit calculates a frequency of the received satellite signal. A frequency processing unit for conversion processing, and a demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit, the frequency processing unit, the demodulation processing unit or the satellite signal calculation unit, This is achieved by a time measuring device with a time adjusting device characterized by being configured to selectively operate.

  According to the present invention, there is provided a receiving unit that receives a satellite signal transmitted from a position information satellite, and a satellite signal calculation that obtains at least satellite time information by calculating the satellite signal received by the receiving unit. And a time information correction unit that corrects the self time information based on the satellite time information, wherein the reception unit receives the received satellite. A frequency processing unit for converting the frequency of the signal; and a demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit, the frequency processing unit, the demodulation processing unit or the satellite signal The calculation units are configured to selectively operate, and the satellite signal calculation unit calculates based on the satellite signals processed by the frequency processing unit and the demodulation processing unit. It is accomplished by time correction method comprising that.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

(First embodiment)
FIG. 1 is a schematic diagram showing a timepiece with a time adjustment device according to the present invention, for example, a wristwatch 10 with a GPS time adjustment device (hereinafter referred to as a “watch with GPS”), and FIG. 2 is a schematic diagram showing a main hardware configuration and the like inside the wristwatch 10. FIG.
As shown in FIG. 1, a GPS wristwatch 10 has a dial 12 on its surface, hands 13 such as long hands and short hands, and a display 27 formed of LEDs and the like for displaying various messages. Yes. The display 27 may be an LCD, an analog display or the like in addition to the LED.

  Further, as shown in FIG. 1, the GPS wristwatch 10 has an antenna 11, and this antenna 11 receives a signal from a GPS satellite 15 orbiting the earth over a predetermined orbit. It has become. The GPS satellite 15 is an example of a position information satellite that orbits the earth.

Further, as shown in FIG. 2, the GPS wristwatch 10 includes a clock mechanism and a GPS mechanism inside thereof, and is configured to exhibit a function as a computer.
That is, the timepiece mechanism in the present embodiment is a so-called electronic timepiece.
Hereinafter, each configuration shown in FIG. 2 will be described.
As shown in FIG. 2, the GPS wristwatch 10 includes a bus 16. The bus 16 includes an MPU (Micro Processing Unit) 17, a general-purpose RAM (Random Access Memory) 18, and a ROM (Read Only Memory) 19.
Etc. are connected.

The bus 16 is also connected to a GPS mechanism that receives satellite signals. In other words, the antenna 11 and the RF unit 20 that uses the received signal as an intermediate frequency (I / F) and the like, and the baseband (BB) unit 21 that demodulates the signal acquired from the RF unit 20 are provided. A signal RAM 22 for storing the signal processed by the RF unit 20 and the signal demodulated by the BB unit 21 is also connected.
That is, the signal received from the GPS satellite 15a and the like in FIG. 1 is processed by the RF unit 20 from the antenna 11 and then stored in the signal RAM 22, and then the BB unit 21 that has acquired the stored signal performs demodulation processing. The signal is also stored in the signal RAM 22.
As described above, the RF unit 20 is an example of a frequency processing unit, the BB unit 21 is an example of a demodulation processing unit, and the signal RAM 22 is an example of a satellite signal storage unit. .
The GPS signal stored in the signal RAM 22 is calculated by the MPU 17 and is extracted as GPS satellite message data, for example, GPS time information (Z count), which will be described later. Details of the signal received from the GPS satellite 15 will be described later.
As described above, the MPU 17 is an example of a satellite signal calculation unit that acquires satellite time information such as Z count.

A clock mechanism is also connected to the bus 16. That is, a real time clock (RTC) 23 made of an IC (semiconductor integrated circuit) or the like, a crystal (Xtal) oscillation circuit 25, or the like. In addition to the crystal oscillation circuit 25, a high-precision oscillator such as a crystal oscillation circuit with a temperature compensation circuit (TCXO) 24 is connected to the bus 16.
Thus, in this embodiment, two types of oscillation circuits are connected. This is because the TCXO 24 with high power consumption but high accuracy and the normal crystal oscillation circuit 25 with low power consumption but low accuracy are used in accordance with the application. Details thereof will be described later.

Also connected to the bus 16 are a power control circuit 26 for controlling a power supply unit composed of a battery, the display 27 shown in FIG. 1, and a counter 29 such as a timer 29.
Since the timer 29 counts time based on the TXCO 24, the timer 29 can measure time with high accuracy.
As described above, the bus 16 has a function of connecting all devices and is an internal bus having an address and a data path. The general-purpose RAM 18 or the like performs processing of a predetermined program and controls the ROM 19 and the like connected to the bus 16. The ROM 19 stores various programs and various information.

  The RTC 23 is an example of a time measuring unit having self time information, and the RF unit 20 is an example of a receiving unit that receives a satellite signal transmitted from a position information satellite (GPS satellite 15). .

FIG. 3 is a schematic diagram showing a main software configuration of the GPS wristwatch 10.
As shown in FIG. 3, the GPS wristwatch 10 has a control unit 28, and the control unit 28 processes various programs in the various program storage units 30 and various data in the various data storage units 40 shown in FIG. 3. It is the composition to do.
In FIG. 3, the various program storage unit 30 and the various data storage unit 40 are shown separately. However, the data is not actually stored separately as described above, and is convenient for explanation. It is described separately for this purpose.

4 is a schematic diagram showing data in the various program storage units 30 of FIG. 3, and FIG. 5 is a schematic diagram showing data in the various data storage units 40 of FIG.
6 and 7 are schematic flowcharts showing main operations and the like of the GPS wristwatch 10 according to the present embodiment.

Hereinafter, the operations of the GPS wristwatch 10 according to the present embodiment will be described in accordance with the flowcharts of FIGS. 6 and 7, and the various programs and data of FIGS.
In the present embodiment, an example will be described in which the GPS wristwatch 10 in FIG. 1 automatically performs time adjustment once a day, that is, once every 24 hours.
When the GPS wristwatch 10 corrects the time of the RTC 23, first, as shown in ST1 of FIG. 6, the RF unit 20 and the signal RAM 22 of FIG. 2 operate to start receiving the satellite signal of the GPS satellite 15. . That is, at this time, the BB unit 21 in FIG. 2 does not operate, and the MPU 17 is configured not to calculate satellite signals.
In this regard, conventionally, the MPU 17 is operated simultaneously with the RF unit 20, the BB unit 21, and the BB unit RAM 22. This is because the satellite signal received by the RF unit 20 or the like via the antenna 11 is continuously processed and the Z count or the like is obtained from the satellite signal.
However, in the present embodiment, while the RF unit 20 receives the satellite signal of the GPS satellite 15, the BB unit 21 and the MPU 17 do not perform calculations and the like, while the BB unit 21 is operating, the RF unit 20. In addition, the MPU 17 does not perform calculations and the like, and the MPU 17 calculates a configuration in which the RF unit 20 and the BB unit 21 do not operate. That is, the calculation of the RF unit 20, the BB unit 21, or the MPU 17 is selectively executed. For this reason, in this Embodiment, it becomes the structure which can avoid that the maximum value (peak value) of power consumption becomes large by operating these simultaneously.

Incidentally, the operation of ST1 is specifically executed by the operation of the RF unit and signal RAM operation program 31 of FIG. That is, the program 31 refers to the RF unit and signal RAM operation start data 41 of FIG. 5, for example, once every 24 hours, and executes the reception of the satellite signal when the time comes. To do.
In addition, while receiving the satellite signal of the GPS satellite, the timer 29 starts to operate using the TCXO 24, and the elapsed time is measured with high accuracy. Specifically, the timer control program 32 of FIG. 4 operates to store the time when the satellite signal reception is started in the reception start time data 42 of FIG. 5 and the timer 29 continues to measure time.
The reception start time data 42 is, for example, “0” seconds.

Next, the GPS wristwatch 10 of the present embodiment performs a process of receiving the satellite signal of the GPS satellite 15.
In ST <b> 2, the satellite signal from the GPS satellite 15 is received by the antenna 11 in FIG. 2, and then this satellite signal is input to the RF unit 20. The RF unit 20 converts the input satellite signal to an intermediate frequency (IF), converts an analog signal into a digital signal, and the like, and then stores it in the signal RAM 22 of FIG. Specifically, it is stored as the RF signal data 49 of FIG.
Thereafter, the process proceeds to ST3. In ST3, it is determined whether or not the reception of the satellite signal of the GPS satellite 15 has passed for a predetermined time, for example, about 1 subframe (about 6 seconds to 6 seconds + .alpha. .
In the present embodiment, the purpose is to acquire the GPS time and time (Z count) from the satellite signal of the GPS satellite 15, and hereinafter, the satellite signal transmitted from the GPS satellite 15 will be described.

FIG. 8 is a schematic explanatory diagram showing satellite signals.
As shown in FIG. 8A, a signal is transmitted from the GPS satellite 15 in units of one frame (30 seconds). This one frame has five subframes (one subframe is 6 seconds). Each subframe has 10 words (1 word is 0.6 seconds).
The head word of each subframe is a TLM word in which TLM (Telemetry word) data is stored, and in this TLM word, as shown in FIG. Is stored.
The word following the TLM is a HOW word in which HOW (hand over word) data is stored, and GPS time information (Z count) of a GPS satellite called TOW (Time of Week) is stored at the top thereof. .

This Z count stores the time of the start portion of the TLM of the next subframe.
The GPS time is displayed in seconds since 0:00 every Sunday, and returns to 0 at 0:00 on the next Sunday.
Thus, by referring to the HOW word that is the second word of the subframe, it is possible to acquire the Z count that is GPS time information. However, when the GPS wristwatch 10 receives a satellite signal transmitted from the GPS satellite 15, it cannot be specified from which part of the subframe the reception starts, so immediately after TOW (Z count) in FIG. 8B. In consideration of the case where reception starts, in this embodiment, the reception time is basically one subframe, that is, 6 seconds.
In consideration of the case where the reception of the satellite signal is started in the middle of the TOW (Z count) in FIG. 8B, the reception time is preferably set to 1 subframe + α, for example, 6.6 seconds.

Thus, if the GPS wristwatch 10 receives the satellite signal until the reception time of about one subframe elapses in ST3, the TOW (Z count) data in FIG. 8 can be obtained.
The Z count received in this way is stored in the signal RAM 22 as will be described later.

In ST3, the reception end availability determination program 34 in FIG. 4 refers to reception time data (for example, 6 seconds or 6.6 seconds) 45 in FIG. To judge. That is, for example, 6 seconds or 6.6 seconds, which is reception time data, is an example of a reception time of about one subframe.
This 6.6 seconds is determined based on the timer 29 in FIG. In other words, the reception ends when the timing data of the timer 29 reaches 6.6 seconds. Specifically, the reception end determination program 35 of FIG.
When the reception end determination program 35 determines that the reception has ended, the RF unit and signal RAM operation program 31 in FIG. 4 operate, and the operation of the RF unit 20 is stopped as shown in ST4.

Next, the process proceeds to ST5. In ST5, the operation of the BB unit 21 in FIG. 2 is started. Specifically, the BB section operation program 39 in FIG. 4 operates.
Specifically, as shown in ST6, the BB unit 21 acquires the RF signal data 49 of FIG. 5 recorded in the signal RAM 22, removes the carrier of the digital signal, and correlates the C / A code. Processes such as phase synchronization are performed. In this way, the BB unit 21 demodulates the satellite signal of the GPS satellite 15.
As described above, since the BB unit 21 uses the RF signal data 49 stored in the signal RAM 22, even if the operation of the RF unit 20 is stopped in ST4, the calculation of the BB unit 21 is not hindered.

Next, in ST7, the satellite signal demodulated by the BB unit 21 is stored in the signal RAM 22 of FIG. Specifically, as shown in FIG. 5, the signal RAM 22 stores the BB signal data 44.
Next, in ST8, the operation of the BB unit 21 is stopped. Specifically, the BB section operation program 39 operates to stop the operation of the BB section.
Since the received and demodulated satellite signals are stored in the BB RAM 22, even if the operation of the BB unit 21 is stopped, the subsequent operations and the like are not hindered.

Next, the process proceeds to ST9. In ST1 to ST8, the calculation for obtaining the Z count or the like from the satellite signal received by the RF unit 20 or the like is not performed. From ST9, the calculation is performed by the MPU 17 or the like in FIG.
As described above, in the present embodiment, while the RF unit 20 is receiving the satellite signal of the GPS satellite 15, power for operation is supplied to the RF unit 20 via the power supply control circuit 26 and the like shown in the figure. However, power for operation is not supplied to the BB unit 21 and the MPU 17. Further, while the operation power is supplied to the BB unit 21, the operation power is not supplied to the RF 20 and the MPU 17. Further, when the MPU 17 starts the operation of calculating the satellite signal as in ST9, the power is supplied to the MPU 17. During this time, the power consumption of the RF unit 20 and the BB unit 21 is stopped or significantly reduced. It becomes the composition which is done.
In other words, the RF unit 20, the BB unit 21, the MPU 17 and the like do not operate at the same time, and any one of them is always operated selectively.
Accordingly, the GPS wristwatch 10 can be configured to suppress an increase in the maximum power value (peak power value).

Next, a process of calculating the BB signal data 44 of FIG. 5 to obtain a Z count and correcting the time of the GPS wristwatch 10 based on the Z count will be described in ST9 to ST12.
First, when the operation of the BB unit 21 is stopped in ST8, the MPU 17 or the like performs an operation for calculating the BB signal data 44 of FIG. 5 stored in the signal RAM 22 of FIG. 2 at that timing (ST9). Specifically, the signal calculation operation program 36 of FIG. 4 operates.
Then, the process proceeds to ST10. In ST10, when the calculation of the signal calculation operation program 36 is completed, the calculation result is stored in the signal calculation result data 46 of FIG. 5, and the time of the timer 29 at the end of the signal calculation is set to the signal calculation end time data 47 of FIG. Register as
For example, if it takes 0.4 seconds from the end of satellite signal reception before calculation shown in ST4 to the end of operation of the BB unit 21 in ST8, and the calculation time of ST9 and ST10 takes 3 seconds, the timing data of the timer 29 is 10 seconds. It becomes.

Such calculation results will be described with reference to the schematic explanatory diagrams of the satellite signal and the received signal in FIG.
In FIG. 9, the upper part shows the satellite signal transmitted from the GPS satellite 15, and the lower part shows the received signal calculated by the GPS wristwatch 10.
First, as shown in FIG. 9, the satellite signal and the received signal are received with a shift of the propagation time β. That is, the propagation time β indicates the time until the satellite signal reaches the GPS wristwatch 10 from the GPS satellite 15. That is, the propagation time β is an example of propagation delay time information.
This propagation time β can be acquired by the GPS wristwatch 10 by grasping the phase of the C / A code in ST3 of FIG. 6 and performing the calculation of ST7.
Further, the arrows a1 to a4 of the GPS signal in FIG. 9 indicate the start portion of each subframe in FIG. 8A. The timing data of this start portion also correlates with the C / A code of the satellite signal, Thereafter, the GPS wristwatch 10 can obtain the calculation.
On the other hand, the arrows b1 to b4 of the lower received signal indicate the start portions of the subframes corresponding to the GPS signals a1 to a4. It can be seen that the arrows b1 to b4 are received with a delay of the propagation time β.

Further, the Z counts Z1 to Z4 in FIG. 9 are the TOWs in FIG. 8B, and this time data indicates the start time of the next subframe. For example, since Z1 in FIG. 9 indicates (00:00: 00 seconds), this time (00:00: 00 seconds) indicates the time of the start portion of the subframe indicated by a2 in FIG. .
As described above, since the subframe has a total length of 6 seconds, the Z counts of a2 to a4 are respectively shifted by 6 seconds.
The GPS wristwatch 10 can obtain the Z count time of the subframe by calculating.

That is, the GPS wristwatch 10 receives and calculates the satellite signal from the GPS satellite 15, and receives the propagation time β, the subframe start timing data a2, etc. (b2 etc. on the receiving side) and the reception shown in FIG. The time data (Z count) at the start of the next subframe after the subframe can be acquired.
Under this premise, when receiving as in the flowchart of FIG.
In other words, it is assumed that the GPS wristwatch 10 starts receiving the satellite signal of the GPS satellite 15 at the portion of FIG. That is, it is ST1 of FIG.
At this time, the timer 29 starts timing, that is, the reception start is “0” seconds. This is stored in the reception start time data 42 of FIG.

The satellite signal reception end of ST4 (operation of the RF unit 20 is stopped) is, for example, 6.6 seconds after the start of reception, and thus becomes “6.6 seconds” on the timer 29.
Further, when the subsequent operation of the BB unit 21 of ST5 to ST8 is 0.4 seconds and the subsequent operation of ST9 and ST10 is, for example, 3 seconds as described above, the time on the timer 29 at the end of the calculation is “10 seconds” (signal calculation end time data 47).

Furthermore, as described above, the GPS wristwatch 10 can obtain the timing data of the start portion of the subframe received in FIG. 9 by calculation or the like, so how many seconds after this timing the reception start time of the timer 29 in FIG. It can be calculated by calculation.
If this time is 3 seconds, for example, the start portion of the subframe indicated by the arrow b2 in the received signal of FIG.

That is, as shown in FIG. 9, the time of the Z count (Z2) acquired from the received signal corresponds to the time of “9 seconds” on the arrow b3, that is, the timer 29.
Furthermore, since “9 seconds” on the timer 29 includes the propagation time β, the time on the timer 29 obtained by subtracting the propagation time β from 9 seconds corresponds to the time of the Z count (Z2). It becomes.
Then, the time obtained by adding “6 seconds” to the time data of the Z count (Z2) is a time obtained by subtracting the propagation time β from the time (15 seconds) of the arrow b4 on the timer 29 (corresponding to a4 in FIG. 9). ).

Therefore, in ST11, the time correction data calculation program 37 of FIG. 4 is operated, and based on the data obtained by calculating the above-described satellite signal and the data measured by the timer 29, the subtraction of the GPS signal that arrives in calculation after the calculation is completed. The start part (a4) of the frame is obtained and stored as time correction data 48 in FIG.
This data is, for example, at the timing of “15 seconds−propagation time β” in the timer 29 at the time “00:00:06” + “6 seconds” of the Z count (Z2), that is, “00:00:12”. The time will be corrected.
In this way, by adding the value obtained by multiplying the Z count received by the GPS wristwatch 10 to the number of subframes that have elapsed until the end of the calculation by 6 seconds and reducing the propagation time β, the timing of time correction can be accurately adjusted. Can be acquired.

Next, as shown in ST12 of FIG. 7, the time correction program 38 of FIG. 4 operates and corrects the RTC 23 of FIG. 2 based on the time correction data 48 of FIG. Will be able to.
When the time adjustment is completed, the operation of the timer 29 in FIG. 2 is completed, and thereafter, only the normal crystal oscillation circuit 25 continues to operate.
In this way, when time accuracy is required, the TCXO 24 in FIG. 2 is used, and in other cases, the use time of the TCXO 24 that consumes a relatively large amount of power can be shortened by using the normal crystal oscillation circuit 25. As a whole, the GPS wristwatch 10 can reduce power consumption.

  As described above, in the present embodiment, the reception and calculation of the satellite signal of the GPS satellite 15 are performed separately, so that the peak power can be reduced and the calculation is performed over time after the reception is stopped. Even so, the time can be corrected with high accuracy. Further, since the timer 29 uses the high-accuracy TCXO 24, the time accuracy is further improved. However, the TCXO 24 is used only when necessary, and when not necessary, the normal crystal oscillation circuit 25 is used. Power consumption can also be reduced.

  In this embodiment, the reception start time data 42 and the signal calculation end time data 47 are used using the timer 29. However, the present invention is not limited to this, and any one of the reception start time data 42 and the signal calculation end time data 47 is used. It is also possible to adopt a configuration in which only one data is measured and the other is obtained by calculation.

In addition, as shown in FIG. 9, the present invention can accurately correct the time of the RTC 23 regardless of the length of time until the end of the calculation. Therefore, the ability of the MPU 17 to perform the calculation such as ST9 in FIG. It can be lowered.
In this case, the power consumption of the MPU can be reduced, and the GPS wristwatch with lower power consumption is obtained.

Incidentally, the time correction program 38 of FIG. 4 is an example of a time information correction unit. The antenna 11, the RF unit 20, and the BB unit 21 are examples of receiving units, and the MPU 17 and the signal calculation operation program 36 of FIG. 4 are examples of satellite signal calculating units.
The reception time data 45 is an example of the reception unit timing information and the satellite signal reception time information, and 6 seconds or 6.6 seconds, which are examples of the reception time data 45, are used for acquiring the satellite time information and the correction timing information. This is an example of the minimum necessary time information.
The signal calculation end time data 47 is an example of satellite signal calculation timing information, and the timer 29 is an example of a counter unit.
The time correction data 48 is an example of correction timing information.

(Second Embodiment)
10 and 11 are schematic blocks showing the main configuration of a GPS wristwatch 100 (see FIG. 1) according to the second embodiment of the present invention, and FIGS. 12 and 13 show the present embodiment. 3 is a schematic flowchart of such a GPS wristwatch 100.
Since the configuration and the like of the GPS wristwatch 100 according to the present embodiment are in common with the configuration of the GPS wristwatch 10 according to the first embodiment described above, the common configuration is described with the same reference numerals and the like. In the following, the description will focus on the differences.

In the present embodiment, unlike the first embodiment, “week number data” and “UTC parameter data” are acquired from the satellite signal of the GPS satellite 15.
As described above, the “Z count” data acquired from the satellite signal displays the elapsed time in seconds from 0 o'clock every Sunday and returns to 0 at 0 o'clock on the next Sunday.
Therefore, when it is necessary to specify time information exceeding the week unit, that is, the date of the time indicated by the Z count, information other than the Z count is required.
That is week number data. For example, the week number data is assigned a serial number in which the week number starting on January 6, 1980 is “0”, and the week number data is included in the subframe shown in FIG. It is included in “Subframe 1”.
Therefore, when the GPS wristwatch 100 corrects the time of the RTC 23 including the date data, this “week number data” is used in addition to the “Z count” acquired in the first embodiment. Need to get.

Further, the date indicated by the week number described above is synchronized with the atomic clock managed by the US Naval Observatory (USNO), and therefore is slightly different from UTC (Coordinated Universal Time). The correction value of this deviation becomes “UTC parameter data”, and this data is stored in “page 18 of subframe 4”.
Therefore, in order for the GPS wristwatch 100 of the present embodiment to accurately grasp the date and time, it is necessary to acquire and correct this UTC parameter data (UTC offset data).
In addition, since UTC is Coordinated Universal Time, Japan Standard Time can be obtained by advancing 9 hours to correct for Japan Time.

As described above, the present embodiment is an example in which the correction value with the date and UTC is acquired when the time is corrected. Then, the process of acquiring the data of the week number for grasping | ascertaining a date using FIG. 12 is demonstrated concretely, Then, the process for acquiring the correction value with UTC is concretely shown using FIG. I will explain it.
As shown in FIG. 12, in the present embodiment, the satellite signal of the GPS satellite 15 is calculated as in the first embodiment described above. At this time, the subframe number (ID) is calculated from the received satellite signal. ) Is acquired (ST9, etc.).
Then, in ST22, it is determined whether or not the received subframe number (ID) is “1”. Specifically, the subframe ID determination program 131 of FIG. If it is determined that the subframe number (ID) is “1”, the process proceeds to ST23, where the week number is decoded.

Next, it progresses to ST24 and it is judged whether the week number was able to be acquired. If the received subframe is not 1 in ST22, if the week number cannot be acquired in ST24, the process proceeds to ST25.
In ST25, the calculation result is registered as the signal calculation result data 46 of FIG. 11 as in the first embodiment. That is, the calculation result includes the propagation time β, the subframe start timing data a2 and the like (b2 and the like on the receiving side), and the received subframe, as shown in FIG. 9, as in the first embodiment described above. Time data (Z count) at the start of the next subframe is included.
In this embodiment, in addition to this, the received subframe number (ID) is registered as subframe ID data 141 in FIG.
Further, the time of the timer 29 at the end of the calculation when the satellite signal calculation is completed is registered as the signal calculation result data 46.

Next, in ST26, the target subframe acquisition program 132 operates to calculate the time of the timer 29 corresponding to the target subframe timing.
For example, when the target subframe is subframe 1 and the received subframe is subframe 3, the start portion of subframe 1 is calculated among the start portions of subframes indicated by arrows a1 and the like in FIG. When the received subframe is “3”, the received Z count is the time of the start portion of subframe 2. Therefore, if the propagation time β is corrected with reference to the time obtained by adding 18 seconds to this time, the timer 29 The beginning of subframe 4 above becomes clear.
Therefore, if a satellite signal is received at the timing of the start portion of subframe 1 based on timer 29, the signal of subframe 1 can be received and week number data can be acquired.

  For this reason, in ST27 and ST28, the time correction data calculation program 37 can correct the RTC 23 based not only on the Z count but also on the week number, so that the date can be accurately corrected.

  The MPU 17 and the signal calculation operation program 36 are examples of the subframe number acquisition unit. Moreover, in this Embodiment, as shown to ST26, it has the structure which receives the target sub-frame of a satellite number based on target sub-frame number information.

Next, a process for obtaining UTC offset data (UTC parameter data) which is a correction value with UTC will be described with reference to FIG.
That is, in order to correct the time, UTC offset data is required in addition to the week number described above, and this data is stored in the UTC offset data 142 of FIG.
The UTC offset data 142 needs to be updated regularly, for example, several times a year, and an update time is set. The flowchart of FIG. 13 executes this update.
First, in ST210 of FIG. 13, it is determined whether or not it is the UTC offset acquisition time. Specifically, the UTC offset acquisition time determination program 134 of FIG.
If it is determined that it is the UTC offset acquisition time, the reception timing is calculated in ST210.
Specifically, the target subframe acquisition program 132 of FIG. 10 works, and the difference time between the received subframe and the page 18 of the frame 4 that is the target subframe is calculated as ST26 of FIG. Ask.

  Next, in ST212, it is determined whether or not it is a reception timing. If the reception timing is reached, a satellite signal is received, and if the UTC offset data can be acquired in ST213, the UTC offset data 142 in FIG. 11 is updated in ST214. To do.

  By periodically updating the UTC offset data 142 in this way, it is possible to more accurately correct the deviation from the UTC when the time of the GPS wristwatch 100 is corrected.

(Third embodiment)
14 and 15 are schematic blocks showing a main configuration of a GPS wristwatch 200 (see FIG. 1) according to the third embodiment of the present invention, and FIG. 16 shows a GPS-attached watch according to the present embodiment. 3 is a schematic flowchart of a wristwatch 200.
Since the configuration of the GPS wristwatch 200 according to the present embodiment is similar to the configuration of the GPS wristwatch 10 according to the first embodiment described above, the common configuration is described with the same reference numerals. In the following, the description will focus on the differences.

In the present embodiment, the GPS wristwatch 200 stores the data of the GPS satellite 15 once received and correlated, and serves as reference data when the GPS satellite 15 is received next time.
Specifically, satellite data is created based on the received Doppler frequency, C / A code phase, signal strength, and the like of the GPS satellite 15.
In other words, the deviation of the Doppler frequency is measured, and the closer the value is to “0”, the more easily the satellite is located at the zenith and can be received. Therefore, by registering the Doppler frequency deviation data in association with the time data when the GPS wristwatch 200 receives the satellite signal of the GPS satellite 15, it is possible to know the GPS satellite 15 that is easily received according to the time.
Such satellite data is registered in the satellite data 241 in FIG. Specifically, the satellite data 241 is recorded in the general-purpose RAM 18 in FIG.

  Further, since the satellite number of the GPS satellite 15 is known from the phase of the C / A code, the satellite number of the GPS satellite 15 that is easy to receive is specified by associating the above-described Doppler frequency deviation data with the satellite number. be able to.

Further, by correlating the signal intensity data with the Doppler frequency deviation data and the satellite number, it is possible to select the GPS satellites 15 having higher reliability and easy reception.
That is, data in which time / satellite number / Doppler frequency deviation / signal intensity are associated with each other is registered in the satellite data 241 in FIG. This satellite data 241 is an example of satellite information that can be captured.

A method of collecting and using such satellite data 241 will be described with reference to the flowchart of FIG. The collection of the satellite data 241 is performed in ST33.
Specifically, the satellite data recording program 231 shown in FIG. 14 operates to record the satellite data 241 as described above.
In ST31 and ST32, the satellite data 241 is used. That is, in ST31, the satellite data presence / absence determination program 232 operates to determine whether or not the satellite data 241 that can be used exists in the satellite data 241.
If the available satellite data 241 is present in ST31, the satellite is promptly received using the satellite data 241 in ST32.
In other words, since the satellite data 241 is recorded with the satellite number closest to the zenith and having the strongest signal intensity at the time, the GPS satellite 15 can be quickly received by receiving the GPS satellite 15 using this data. Since reception is possible, power consumption can be kept low.

(Fourth embodiment)
FIG. 17 is a schematic flowchart showing a GPS wristwatch according to the fourth embodiment of the present invention.
Since the configuration and the like of the GPS wristwatch according to the present embodiment are similar to the configuration of the GPS wristwatch 200 according to the third embodiment described above, the common configuration is described with the same reference numerals. Omitted, the following description will focus on the differences.

In the GPS wristwatch according to the present embodiment, as a form to be added to the flowchart of the third embodiment of FIG. 16, a flowchart for acquiring only the satellite data 241 of the GPS satellite 15 is added as shown in FIG. Yes. That is, the flowchart in FIG. 17 does not acquire the Z count from the satellite signal, and is intended to acquire only the satellite data 241 periodically.
For this reason, the satellite signal reception time of the GPS satellite 15 is C / A code length (1 msec) to message 1 bit length (20 msec).

Specifically, in ST41 of FIG. 17, the RF unit 20, the BB unit 21, and the signal RAM 22 operate to receive satellite signals, and in ST43, the BB unit 21 removes the carrier and converts the C / A code. It is the structure which performs a correlation process.
In ST42, for example, the satellite signal of the GPS satellite 15 is received only for 20 msec, which is the message 1-bit length.
As described above, in the process of FIG. 17, the Z count is not acquired, but only for acquiring the satellite data 241 of the third embodiment in order to quickly perform future satellite reception. Therefore, the satellite data 241 can be acquired quickly and effectively.

(Fifth embodiment)
FIG. 18 is a schematic flowchart showing a GPS wristwatch according to the fifth embodiment of the present invention.
Since the configuration of the GPS wristwatch according to the present embodiment is similar to the configuration of the GPS wristwatch 10 according to each of the above-described embodiments, the description of the common configuration is omitted with the same reference numerals. Hereinafter, the differences will be mainly described.

In the present embodiment, unlike each of the above-described embodiments, once the satellite signal is received from the GPS satellite 15 and the Z count (time information) is acquired, the accuracy of the Z count is confirmed again. The same GPS satellite 15 receives the satellite signal and acquires the Z count.
Then, by comparing these two Z count values, the consistency is judged, and when there is consistency, the time of the RTC 23 is corrected.

Specifically, in ST51 of FIG. 18, it is determined whether or not there is previous satellite data. If there is no previous satellite data, in ST52, the same GPS satellite 15 correlated this time is received again, Obtain satellite signal and get Z count.
In ST53, a consistency determination program (not shown) operates to determine consistency.
Therefore, when the Z count obtained in the first reception is calculated based on an erroneous signal due to noise or the like, the error can be quickly grasped, and the time correction accuracy is greatly improved.
The consistency determination program is an example of the consistency determination unit.

(Sixth embodiment)
FIG. 19 is a schematic flowchart showing a GPS wristwatch according to the sixth embodiment of the present invention.
Since the configuration of the GPS wristwatch according to the present embodiment is similar to the configuration of the GPS wristwatch according to the fifth embodiment described above, the description of the common configuration is omitted with the same reference numerals. Hereinafter, the differences will be mainly described.

  In the present embodiment, unlike the above-described fifth embodiment, after receiving satellite signals from a plurality of different GPS satellites 15 and acquiring a plurality of Z counts (time information), the accuracy of these Z counts is confirmed. Therefore, the consistency is determined by comparing the values of the plurality of Z counts, and when there is consistency, the time of the RTC 23 is corrected.

Specifically, in ST61 in FIG. 19, it is determined whether or not satellite signals of a plurality of different GPS satellites 15 are stored in the signal RAM 22, and if they are stored, in ST62, these Z counts are matched. It is determined whether or not sex is obtained.
That is, a different satellite data matching judgment program (not shown) operates to judge the consistency of them.
When there is consistency, the RTC 23 corrects the time. As described above, in this embodiment, since the consistency of Z counts acquired from different GPS satellites 15 is determined, the time can be corrected with a more accurate Z count.
This different satellite data consistency determination program is an example of the different satellite consistency determination unit.

  The present invention is not limited to the above-described embodiment. In the above-described embodiment, a GPS satellite orbiting the earth is described as an example of the position information satellite. However, the position information satellite of the present invention is not limited to this, and a geostationary satellite, a quasi-zenith satellite, and the like are also included. included.

It is the schematic which shows the timepiece with a time adjustment apparatus which concerns on this invention, for example, the wristwatch with a GPS time adjustment apparatus. It is the schematic which shows the main hardware constitutions etc. inside the wristwatch with GPS of FIG. It is the schematic which shows the main software configurations etc. of the wristwatch with GPS. It is the schematic which shows the data in the various program storage part of FIG. It is the schematic which shows the data in the various data storage part of FIG. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with GPS concerning 1st Embodiment. It is another schematic flowchart which shows the main operation | movement etc. of the wristwatch with GPS concerning 1st Embodiment. It is a schematic explanatory drawing which shows a satellite signal. It is a schematic explanatory drawing of a satellite signal and a received signal. It is a schematic block which shows the main structures of the wristwatch with GPS concerning 2nd Embodiment. It is another schematic block which shows the main structures of the wristwatch with GPS concerning 2nd Embodiment. It is a schematic flowchart of the wristwatch with GPS concerning a 2nd embodiment. It is another schematic flowchart of the GPS wristwatch according to the second embodiment. It is a schematic block which shows the main structures of the wristwatch with GPS concerning 3rd Embodiment. It is another schematic block which shows the main structures of the wristwatch with GPS concerning 3rd Embodiment. It is a schematic flowchart of the wristwatch with GPS concerning a 3rd embodiment. It is a schematic flowchart which shows the wristwatch with GPS concerning 4th Embodiment. It is a schematic flowchart which shows the wristwatch with GPS concerning 5th Embodiment. It is a schematic flowchart which shows the wristwatch with GPS concerning 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wristwatch with GPS time correction device, 15 ... GPS satellite, 17 ... MPU, 18 ... General-purpose RAM, 20 ... RF unit, 21 ... BB unit, 22 ... Signal RAM, 23 ... RTC, 24 ... TCXO, 25 ... crystal oscillation circuit, 26 ... power supply circuit, 29 ... timer, 30 ... various program storage units, 40 ... various Data storage unit, 31... RF unit and signal RAM operation program, 32... Timer control program, 34... Reception end enable / disable determination program, 35. 37, time correction data calculation program, 38 ... time correction program, 39 ... BB section operation program, 41 ... RF section, BB section and BB section RAM operation start data 42 ... reception start time data, 44 ... BB signal data, 45 ... reception time data, 46 ... signal calculation result data, 47 ... signal calculation end time data, 48 ... time Correction data, 49 ... RF signal data, 131 ... Subframe ID determination program, 132 ... Target subframe acquisition program, 141 ... Subframe ID data, 231 ... Satellite data recording program 232 ... Satellite data existence determination program, 241 ... Satellite data

Claims (13)

A receiving unit for receiving a satellite signal transmitted from the position information satellite;
Calculating the satellite signal received by the receiving unit, at least acquiring satellite time information; and
A timekeeping section having self-time information;
A time information correction unit that corrects the self time information based on the satellite time information,
The receiver is
A frequency processing unit for converting the frequency of the received satellite signal;
A demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit,
The time correction device, wherein the frequency processing unit, the demodulation processing unit, or the satellite signal calculation unit is configured to selectively operate.   The time correction apparatus according to claim 1, further comprising a satellite signal storage unit that stores the satellite signals processed by the frequency processing unit and the demodulation processing unit. A counter unit for acquiring reception unit timing information that is operation-related time of the reception unit and / or satellite signal calculation timing information that is operation-related time of the satellite signal calculation unit;
The time information correction unit is configured to correct the self-time information based on correction timing information calculated based on the reception unit timing information and / or the satellite signal calculation timing information. The time correction apparatus according to claim 1 or 2.   The time correction apparatus according to any one of claims 1 to 3, wherein the satellite signal includes propagation delay time information that is a time required for the satellite signal to reach the position information satellite. The reception unit timekeeping information includes satellite signal reception time information which is a time at which the reception unit receives a satellite signal of the position information satellite,
5. The satellite signal reception time information is the minimum necessary time information for acquiring the satellite time information and the correction timing information, according to any one of claims 3 and 4. Time correction device.   6. The time adjustment device according to claim 3, wherein the counter unit is configured to operate based on a high-precision oscillator. The satellite signal includes subframe number information,
A subframe number acquisition unit that acquires target subframe number information including week number information of GPS time and / or UTC (universal time coordinated) parameters information from the subframe number information;
The time correction apparatus according to any one of claims 1 to 6, wherein the time correction apparatus is configured to receive the target subframe of the satellite signal based on the target subframe number information. The satellite signal includes satellite number information, Doppler frequency information and C / A code phase information of the position information satellite,
8. A captureable satellite information storage unit that stores satellite number information, Doppler frequency information, and C / A code phase information of the received position information satellite, according to claim 1. Time correction device.   8. The time correction apparatus according to claim 5, wherein the satellite signal reception time information is a C / A code length or a message 1 bit length. The satellite signal is received a plurality of times from the same position information satellite,
10. The time correction apparatus according to claim 1, further comprising: a consistency determination unit configured to determine consistency of the plurality of satellite time information acquired by the reception of the plurality of times. It is configured to receive the satellite signals from a plurality of the location information satellites,
10. The time correction according to claim 1, further comprising: a different satellite consistency determination unit that determines consistency of the plurality of pieces of time information acquired from the plurality of the position information satellites. apparatus. A receiving unit for receiving a satellite signal transmitted from the position information satellite;
Calculating the satellite signal received by the receiving unit, at least acquiring satellite time information; and
A timekeeping section having self-time information;
A time information correction unit that corrects the self time information based on the satellite time information,
The receiver is
A frequency processing unit for converting the frequency of the received satellite signal;
A demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit,
The timekeeping device with a time adjustment device, wherein the frequency processing unit, the demodulation processing unit, or the satellite signal calculation unit is configured to selectively operate. A receiving unit for receiving a satellite signal transmitted from the position information satellite;
Calculating the satellite signal received by the receiving unit, at least acquiring satellite time information; and
A timekeeping section having self-time information;
A time information correction unit that corrects the self-time information based on the satellite time information,
The receiver is
A frequency processing unit for converting the frequency of the received satellite signal;
A demodulation processing unit for demodulating the satellite signal converted by the frequency processing unit,
Each of the frequency processing unit, the demodulation processing unit or the satellite signal calculation unit is configured to selectively operate,
The time correction method, wherein the satellite signal calculation unit calculates based on the satellite signals processed by the frequency processing unit and the demodulation processing unit.

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