JP5034837B2 - Time correction device, time measuring device with time correction device, and time correction method - Google Patents

Description

  The present invention relates to a time adjustment device that corrects time based on a signal from, for example, 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. This GPS satellite is provided with an atomic clock and has extremely accurate time information (GPS time).
For this reason, conventionally, a time correction method using time information of GPS satellites has been proposed in order to perform highly accurate time correction (for example, Patent Document 1, paragraph 0005).

In order to acquire atomic clock data from the GPS satellite, it is necessary to capture the GPS satellite and synchronize with the GPS satellite signal.
However, since the GPS satellite is constantly moving, it is necessary to predict and acquire the position of the GPS satellite from the orbit data of the GPS satellite in order to acquire the GPS satellite. In addition, in order to obtain accurate time data, it is necessary to acquire a plurality of, for example, four GPS satellites and obtain a propagation delay time to the receiver.
In addition, it takes a normal time to capture the four GPS satellites moving in this way. Furthermore, in addition to this, when a GPS satellite signal receiver is provided in a clock or the like that always moves with the user, the receiver also moves, making it even more difficult to capture the GPS satellite. Therefore, it takes a long time to capture four GPS satellites.

For this reason, a device such as a clock that requires low power consumption does not capture four GPS satellites, but captures a single GPS satellite and synchronizes with the GPS satellite signal. Need to get the data.
JP 08-15463 (paragraph "0005" etc.)

  However, the time data obtained by capturing a single GPS satellite is data including a propagation delay time that depends on the distance until the receiver side receives the satellite signal from the GPS satellite. For this reason, there has been a problem that it is not possible to correct the time more precisely.

  Therefore, an object of the present invention is to provide a time adjustment device, a time measuring device with a time adjustment device, and a time adjustment method capable of highly accurate time adjustment even when a single GPS satellite is captured.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A candidate satellite selection unit that selects a candidate location information satellite from a plurality of location information satellites, a reception unit that receives the satellite signals transmitted from the plurality of location information satellites for each of the candidate location information satellites, and the reception unit At least satellite time information is acquired from the received satellite signal, and a correction time information acquisition unit that acquires correction time information based on the satellite time information; a time information generation unit that generates time information; and the correction Comparing the time information with the time information, a correction time information determination unit that determines whether the correction time information is ahead of the time information, and based on a determination result of the correction time information determination unit, A time information correction unit comprising: a time information correction unit having a configuration for correcting the time information based on the most advanced correction time information.

According to the above configuration, the candidate satellite selection unit selects a candidate location information satellite from a plurality of location information satellites, and the correction time information acquisition unit is transmitted from the location information satellite received by the reception unit for each candidate location information satellite. At least satellite time information of the satellite signal is acquired, and corrected time information is acquired based on the satellite time information. Then, the correction time information determination unit compares the correction time information with the time information generated by the time information generation unit, and determines whether the correction time information is ahead of the time information. Further, the time information correction unit corrects the time information based on the correction time information that is relatively advanced among the correction time information based on the determination result of the correction time information determination unit.
Since this correction time information is acquired based on the satellite time information acquired from the satellite signal received by the reception unit from the satellite signal transmitted from the position information satellite, when the reception unit receives the satellite signal, Is information including the propagation delay time depending on the distance between the position information satellite and the receiving unit. However, in the present invention, the time information correction unit can correct the time information based on the correction time information based on the determination result of the correction time information determination unit.
For this reason, time information can be corrected at a more accurate time with a small propagation delay time. As a result, the time information can be corrected based on the satellite signal from the nearest position information satellite.

[Application Example 2]
Preferably, the correction time information acquisition unit has a configuration to acquire the correction time information based on the satellite time information for each satellite signal of the candidate position information satellite received by the reception unit, The time correction device comprises a configuration in which the correction time information determination unit makes a determination by sequentially comparing with the time information for each of the correction time information acquired by the correction time information acquisition unit.

According to the configuration, the correction time information acquisition unit acquires the correction time information based on the satellite time information for each satellite signal received by the reception unit. And a correction time information judgment part compares with time information in order for every acquired correction time information, and judges it.
Therefore, at the time of reception, the receiving unit does not receive satellite signals transmitted from a plurality of position information satellites at a time, but receives each position information satellite, and the correction time information acquisition unit receives the satellite time from the satellite signal. Since the information is acquired and corrected time information is compared with the display time information by the corrected time information determination unit, the power consumed at one time can be suppressed.

[Application Example 3]
Preferably, when the receiving unit receives the satellite signal for the first time from the candidate position information satellite, the time information correcting unit includes the satellite time included in the first received satellite signal. A time correction apparatus comprising a configuration that is corrected by correction time information based on information.

  According to the above configuration, when the reception unit first receives a satellite signal from the candidate position information satellite, the time information correction unit can correct the time information based on the correction time information based on the satellite time information of the satellite signal. It is like that.

[Application Example 4]
Preferably, after the receiving unit receives the satellite signal from the candidate position information satellite, it further includes a position information satellite determination unit that determines another candidate position information satellite that can be received from a plurality of the position information satellites. When the time information correction unit determines that there is no candidate position information satellite that can be received by the position information satellite determination unit after correcting the time information based on the correction time information, a fixed propagation is further performed. A time correction apparatus having a configuration for correcting a delay time.

According to the configuration, after the receiving unit receives the satellite signal from the candidate position information satellite, the receiving unit further includes the position information satellite determining unit that determines another receivable position information satellite. If it is determined that there is no receivable candidate position information satellite, the time information correction unit corrects the time information based on the correction time information, and further corrects the fixed propagation delay time.
Thus, since the fixed propagation delay time is further corrected from the corrected time information, it is possible to obtain a time with less influence of the propagation delay time.

[Application Example 5]
Preferably, the position information satellite is a GPS (Global Positioning System) satellite, and the fixed propagation delay time is a propagation delay of the satellite signal transmitted from the position information satellite located in the zenith direction from the receiving unit. A time correction device characterized by time.

According to the above configuration, the position information satellite is a GPS (Global Positioning System) satellite, and the fixed propagation delay time is the propagation delay time of the satellite signal transmitted from the position information satellite located in the zenith direction from the receiving unit. ing.
The time information correction unit is corrected by the correction time information that is advanced from the time information, and when there is no position information satellite that can be received by the reception unit, the time information correction unit further adds the fixed propagation delay time. This is because the correction time information is information including a propagation delay time that depends on the distance between the receiving unit and the position information satellite.
In other words, the time information correction unit obtains time information with a smaller propagation delay time by selecting and correcting the correction time information that is ahead of the time information when more accurate time information is desired. Can do. The corrected time information for correcting the time information is finally information including a propagation delay time when a satellite signal from a position information satellite closest to the receiving unit is received. Therefore, more accurate time information can be obtained by adding and correcting the propagation delay time when transmitted from the position information satellite closest to the receiving section, that is, the position information satellite positioned in the zenith direction from the receiving section. And can be.

[Application Example 6]
A candidate satellite selection unit that selects a candidate location information satellite from a plurality of location information satellites, a reception unit that receives the satellite signals transmitted from the plurality of location information satellites for each of the candidate location information satellites, and the reception unit At least satellite time information is acquired from the received satellite signal, and a correction time information acquisition unit that acquires correction time information based on the satellite time information; a time information generation unit that generates time information; and the correction A correction time information determination unit that compares the time information with the time information to determine whether the correction time information is ahead of the time information, and based on the determination result of the correction time information determination unit, A time information correction unit having a configuration for correcting the time information based on the correction time information that is most advanced among the correction time information. Positive apparatus with a timing device.

[Application Example 7]
A candidate satellite selection unit that selects a candidate location information satellite from a plurality of location information satellites, a reception unit that receives the satellite signals transmitted from the plurality of location information satellites for each of the candidate location information satellites, and the reception unit At least satellite time information is acquired from the received satellite signal, and a correction time information acquisition unit that acquires correction time information based on the satellite time information; a time information generation unit that generates time information; and the correction Comparing the time information with the time information, a correction time information determination unit that determines whether the correction time information is ahead of the time information, and the correction time information based on a determination result of the correction time information determination unit A time information correction unit comprising a step of correcting the time information based on the correction time information that is relatively advanced.

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.

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 “GPS wristwatch”), 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, a second hand, a minute hand, an hour hand, and other hands 13 on its surface, and a display 14 including an LCD display panel on which various messages are displayed. Is formed.

As shown in FIG. 1, the GPS wristwatch 10 has an antenna 11, which is a GPS satellite 15a, 15b, 15c, 15d or the like orbiting the earth over a predetermined orbit. The signal is received for each GPS satellite 15a or the like.
The GPS satellites 15a to 15d are examples of position information satellites.

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 an IF (interface), an I / O (input / output (input / output)), and a power supply line 16. A CPU (Central Processing Unit) 17, a RAM (Random Access Memory) 18, a ROM (Read Only Memory) 19, and the like are connected.
Also, the IF, I / O, and power supply line 16 are connected to an antenna 11, a filter (SAW) 20, an RF 21, a baseband (BB) 22, and the like, which are, for example, GPS mechanisms that receive satellite signals. .
That is, the signal received from the GPS satellite 15a or the like of FIG. 1 is demodulated from the antenna 11 via the filter (SAW) 20 to the RF 21 using the received signal as an intermediate frequency, and further the signal acquired via the RF 21. The baseband (BB) 22 is extracted as a signal demodulated. Details of signals received from the GPS satellites 15a and the like will be described later. Here, the antenna 11, the filter (SAW) 20, the RF 21, the baseband (BB) 22, and the like, which are GPS mechanisms, are examples of a receiving unit that receives a satellite signal transmitted from the GPS satellite 15 a or the like.

A clock mechanism is also connected to the IF, I / O, and power supply line 16. That is, a real-time clock (RTC) 23, a crystal oscillation circuit with temperature compensation circuit (TCXO) 24, and the like are connected. Further, the display 14 shown in FIG. 1 is connected to the IF, I / O, and power supply line 16.
As described above, the IF, I / O, and power supply line 16 have a function of connecting all devices, and are internal wiring having an address, a data bus, a power supply line, and various I / Os. In addition to processing a predetermined program, the CPU 17 controls the IF, I / O, ROM 19 connected to the power line 16 and the like. The ROM 19 stores various programs and various information.
The RTC 23 or the like that is a clock mechanism is an example of a time information generation unit that generates time information.

3 to 5 are schematic views showing the main software configuration and the like of the GPS wristwatch 10, and FIG. 3 is an overall view.
As shown in FIG. 3, the GPS wristwatch 10 has a control unit 25, and the control unit 25 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 in this way, and for convenience of explanation. It is divided and described.

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.
FIG. 6 is a schematic flowchart 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 according to the schematic flowchart of FIG. 6, and the various programs and various data of FIGS.

In the present embodiment, a case where the GPS wristwatch 10 in FIG. 1 automatically corrects the time once a day, that is, once every 24 hours will be described as an example.
When the GPS wristwatch 10 corrects the time of the RTC 23, first, in ST1 of FIG. 6, scanning of the GPS satellite 15a etc. is started to select a candidate GPS satellite 15a etc. from a plurality of GPS satellites in the sky. In ST2, it is determined whether or not acquisition of one GPS satellite 15a arbitrarily selected from the candidate GPS satellites 15a has been successful.
Specifically, the GPS satellite scan program 31 shown in FIG. 4 refers to the GPS satellite scan data 41 shown in FIG. 5, and the GPS mechanism (antenna 11, filter (SAW) 20, RF21, baseband (BB) 22 shown in FIG. Etc.) to adjust the generation timing of the C / A code pattern of the GPS satellite 15a, etc., receive the signal of the GPS satellite 15a etc. from the antenna 11, and search for the GPS satellite 15a etc. that can be captured To do. The C / A code is data unique to each GPS satellite 15a and the like, and the C / A code pattern data is stored in the GPS satellite scan data 41 of FIG. The GPS satellite scan program 31 is an example of a candidate satellite selection unit.
Then, when it cannot be captured in ST2, the GPS satellite scan program 31 in FIG. 4 is terminated assuming that the environment is indoors and the GPS satellite 15a or the like cannot be captured.

  If the acquisition of one GPS satellite 15a or the like is successful in ST2, the process proceeds to ST3 and is synchronized with the C / A code from the GPS satellite 15a or the like that has been acquired, as shown in FIG. Synchronizes the preamble and TOW.

Hereinafter, signals transmitted from the GPS satellite 15a and the like will be described. FIG. 7 is a schematic diagram showing a GPS satellite signal which is an example of a satellite signal transmitted from the GPS satellite 15a or the like.
As shown in FIG. 7A, signals are transmitted from each GPS satellite 15a and the like 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 first word of each subframe is a TLM word in which TLM (Telemetry word) data is stored. Preamble data is stored in the TLM word as shown in FIG. 7B. Has been.

The word following the TLM is a HOW word in which HOW (handover) data is stored, and GPS time information (Z count) of a GPS satellite called TOW (Time of Week) is stored at the head thereof. Then, 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.
The GPS time is displayed in seconds since 0:00 every Sunday, and returns to 0 at 0:00 on the next Sunday. And since the week number of GPS is attached | subjected about this one week, it has the structure by which the receiving side can acquire GPS time by acquiring the data of a week number and elapsed time (second). The starting point of this GPS time is UTC (at the time of global agreement).
In order to acquire such frame data of the GPS satellite 15a and the like, it is necessary for the receiving side to synchronize with the signal of the GPS satellite 15a and the like. In particular, the C / A code (1023chip (1023chip ( 1 ms)) is used.

  Since the signal from the GPS satellite 15a etc. is transmitted as described above, in this embodiment, as shown in ST3 of FIG. 6, the C / A code and phase from one captured GPS satellite 15a etc. Synchronization is performed with the TLM word preamble and the HOW word TOW shown in FIG.

Then, the process proceeds to ST4. In ST4, the GPS time is acquired from the received TOW of FIG. 7B, but the ephemeris (detailed orbit information for each GPS satellite 15a etc.) and almanac (all GPS satellites 15a etc.) shown in FIG. Data such as the approximate orbit information of the GPS satellites 15a) is not acquired. Specifically, the GPS satellite time data acquisition program 33 in FIG. 4 acquires the GPS time from the received TOW in FIG. 7B and stores it as the correction time data 43 in FIG.
Here, the GPS satellite time data acquisition program 33 acquires at least satellite time information (for example, GPS time) from the satellite signal (for example, GPS satellite signal) received by the receiving unit (for example, the antenna 11). This is an example of a correction time information acquisition unit that acquires correction time information (for example, correction time data 43) based on the satellite time information.

  Next, proceeding to ST5, it is determined whether the correction time data 43 in FIG. 5 is ahead of the display time data 44. Specifically, the correction time information determination program 34 in FIG. 4 compares the correction time data 43 in FIG. 5 with the display time data 44, and the correction time data 43 advances from the display time data 44. Judge whether or not. Here, the display time data 44 is an example of time information generated by a time information generation unit (for example, the RTC 23). 4 compares the correction time information (for example, correction time data 43) with the time information (for example, display time data 44), and the correction time information advances from the time information. This is an example of a correction time information determination unit that determines whether or not

  If it is determined in ST5 that the correction time data 43 is not advanced from the display time data 44, the process proceeds to ST6. In ST6, it is determined whether or not N = 0. This N = 0 is the number of times of time correction in the time adjustment of the GPS wristwatch 10 once a day, that is, once every 24 hours, and is stored in the correction count data 45 of FIG. . That is, the supplement of the GPS satellite 15a or the like is the first supplement in the time correction of the GPS wristwatch 10 once a day, that is, once in 24 hours, and the time correction has not yet been performed. In this case, the data stored in the correction count data 45 is N = 0. Therefore, if it is determined in ST6 that N = 0, the process proceeds to ST7. On the other hand, if N = 0 is not satisfied in ST6, the process proceeds to ST10 described later to determine whether other candidate GPS satellites 15a and the like can be captured.

By the way, if it is determined in ST5 that the correction time data 43 is advanced from the display time data 44, the process proceeds to ST7. In ST7, the display time data is corrected based on the correction time data. Specifically, the time correction program 35 in FIG. 4 corrects the display time data 44 based on the correction time data 43 in FIG.
Here, in the time correction program 35 of FIG. 4, the correction time information determination unit (for example, the correction time information determination program 34) has the correction time information (for example, correction time) for the time information (for example, the display time data 44). If it is determined that the data 43) is advanced, the time information correction unit corrects the time information (for example, the display time data 44) based on the correction time information (for example, the correction time data 43). ing.

  Then, the process proceeds to ST8, and the display on the dial 12 of the GPS wristwatch 10 in FIG. 1 (hand 13 and the like) is based on the UTC data obtained from the GPS satellite 15a and the like, and the display time data 44 in FIG. Will be corrected. Therefore, for example, Japan time considering the time difference is displayed. When this process is completed, N = 1 is recorded in the correction count data 45 shown in FIG. The correction count data 45 is incremented by 1 when the steps ST1 to ST8 are completed. Therefore, when the second time of the steps from ST1 to ST8 is completed, the correction count data 45 is recorded as N = 1 + 1 = 2, and when the third time is finished, N = 2 + 1 = 3 is recorded. Yes.

Next, the process proceeds to ST9. In ST9, for example, it is determined whether the steps from ST1 to ST8 have been repeated four times. That is, it is determined whether N = 4 is recorded in the correction count data 45 shown in FIG. If it has been repeated four times, the process proceeds to step ST10 described later. On the other hand, if N = 4 is not recorded, the process proceeds to the next step ST9.
In this way, the steps ST1 to ST8 are set to be repeated several times.
That is, by repeating the steps ST1 to ST8, the time display of the GPS wristwatch 10 is the shortest distance from the GPS wristwatch 10, for example, the satellite signal transmitted from the GPS satellite 15a located near the zenith. Is corrected by the correction time data 43 based on the satellite time information.

Next, the process proceeds to ST10, where it is determined whether or not other candidate GPS satellites 15a can be captured.
Specifically, other candidate GPS satellites other than one candidate GPS satellite 15a or the like arbitrarily received from the candidate GPS satellite 15a or the like selected in ST1 by the other satellite capture determination program 32 in FIG. It is determined whether or not reception of 15a or the like is possible. Here, the other satellite acquisition determination program 32 is an example of a position information satellite determination unit.
If it is determined that reception is possible, the process returns to ST1 described above to select other candidate GPS satellites 15a, etc., and captures the GPS satellites 15a again, for display in FIG. The time data 44 is corrected.
If it is determined in ST10 that other candidate GPS satellites 15a cannot be captured, the process proceeds to ST11. In ST11, the display time correction program 36 shown in FIG. 4 further corrects the corrected display time data 44 shown in FIG. 5 by adding the fixed propagation delay time data 42 (eg, 70 ms) shown in FIG. 12 corrects the time display of the hand 13 on the top. Then, the process proceeds to ST12 where N = 0. That is, the data of the correction count data 45 shown in FIG. 5 is reset. This is because the correction count data 45 is set to N = 0 in the initial state for the next day, which is the next time correction timing of the wristwatch 10, and the time correction process can be performed from the next day or ST1. It is because it is doing. In ST11, the data of the correction count data 45 is reset, and a series of time correction processes is completed.
Here, the display time correction program 36 corrects the time information (for example, the display time data 44) based on the correction time information (for example, the correction time data 43), and then determines the position information satellite determination unit (for example, other If the satellite acquisition determination program 32) determines that there is no candidate position information satellite (for example, GPS satellite 15a) that can be received, the fixed propagation delay time (for example, fixed propagation delay time data 42) is further corrected. This is an example of a time information correction unit.

As described above, the steps ST1 to ST8 are repeatedly performed about four times, so that the display time data 44 in FIG. 5 is the shortest distance from the GPS wristwatch 10, for example, the GPS located near the zenith. The correction time data 43 of FIG. 5 based on the satellite time information of the satellite signal transmitted from the satellite 15a or the like has already been corrected.
However, even in this case, the correction time data 43 is data including the propagation delay time.
Therefore, finally, in the step ST11, the time of the GPS wristwatch 10 is displayed by adding the time corresponding to the propagation delay time of the GPS satellite 15a (high elevation angle) located at the zenith to thereby display the propagation delay. More accurate time can be displayed with less time.
Here, the fixed propagation delay time data 42 in FIG. 5 is a satellite signal transmitted from the GPS satellite 15a or the like disposed near the zenith of the GPS wristwatch 10 on the receiving unit side among the GPS satellites 15a and the like. Data corresponding to the propagation delay time.

The propagation delay time is a time required for the GPS wristwatch 10 on the receiving unit side to start receiving a satellite signal transmitted from the GPS satellite 15a or the like.
Referring to FIG. 8, the GPS satellite 15a or the like orbits the earth and moves. Then, assuming that the observation position A is the location of the GPS wristwatch 10 on the receiving unit side, a GPS satellite in the zenith (almost directly above) direction of the observation position A (positioned from the observation position A in a direction perpendicular to the earth surface). The distance between 15a and the observation position A is, for example, about 20200 km. The GPS satellite 15a and the like are also referred to as a high elevation angle GPS satellite 15a. The distance between the high-elevation GPS satellite 15a and the observation point A is about 20200 km, and the speed of light (electromagnetic wave transmission speed) c is 2.9979458 × 10 ⁸ m / s (seconds). Therefore, the GPS wristwatch 10 at the observation position A can receive the satellite signal transmitted from the GPS satellite 15a or the like after about 67 ms (milliseconds).

The distance between the GPS satellite 15b located in the direction close to the horizon from the observation position A and the observation position A is, for example, about 258000 km. Then, the GPS wristwatch 10 at the observation position A can receive the satellite signal transmitted from the GPS satellite 15b after about 89 ms (milliseconds). The GPS satellite 15b located in the direction close to the horizon from the observation position A is also referred to as a low elevation GPS satellite 15b.
As described above, the timing at which the GPS wristwatch 10 at the observation position A receives the satellite signal transmitted from the GPS satellite 15a or the like depends on the distance between the GPS satellite 15a and the GPS wristwatch 10 on the receiving side ( The timing is delayed by about 67 ms (milliseconds) to about 89 ms (milliseconds). The time depending on the distance between the GPS satellite 15a and the like and the GPS wristwatch 10 on the receiving side is the propagation delay time.

In this embodiment, a time corresponding to the propagation delay time of the high elevation GPS satellite 15a or the like is set as the fixed propagation delay time data 42 in FIG.
That is, as described above, the fixed propagation delay time data 42 is obtained from the position information satellite (the GPS satellite 15a (high elevation angle) in FIG. 8) positioned in the zenith direction from the receiving unit (for example, the GPS wristwatch 10 provided with the antenna 11). This is an example of a fixed propagation delay time, which is a propagation delay time of a satellite signal transmitted from.

The above-described steps ST1 to ST8 of the present embodiment compare the display time data 44 and the correction time data 43 in FIG. 5, and when the correction time data 43 is ahead of the display time data 44, The correction is performed using the advanced correction time data 43. The correction time data 43 is time data based on the satellite time information of the satellite signal transmitted from the GPS satellite 15a or the like, and is acquired from the satellite signal such as the GPS satellite 15a received by the GPS wristwatch 10. It has come to be.
Therefore, the correction time data 43 is data including the above-described propagation delay time when the GPS wristwatch 10 receives the correction time data 43. That is, the data is delayed by this propagation delay time.
Therefore, by correcting with the correction time data 43 that is ahead of the display time data 44, the correction can be performed with data at a time with a short propagation delay time.

  In addition, by repeatedly performing the steps ST1 to ST8 of the present embodiment, the time information correction unit (for example, the time correction program 35) can select a candidate position information satellite (for example, a plurality of position information satellites). Among the correction time information (for example, correction time data 43) acquired based on the satellite time information (for example, GPS time) of the satellite signal transmitted from the GPS satellite 15a or the like, it is the most advanced. Time information (for example, display time data 44) can be corrected based on the correction time information. Therefore, more accurate time correction with a small propagation delay time can be performed.

And the GPS wristwatch 10 of this Embodiment is equipped with the following structures by the process of above-mentioned ST1-ST10.
That is, the receiving unit (for example, the antenna 11 or the like) receives satellite signals transmitted from a plurality of position information satellites (for example, GPS satellites) for each candidate position information satellite (for example, the GPS satellite 15a). The correction time information acquisition unit (for example, GPS satellite time data acquisition program 33) corrects the correction time information based on the satellite time information (for example, GPS time) for each satellite signal of the candidate position information satellite received by the reception unit. (For example, correction time data 43) is acquired. Further, the correction time information determination unit (for example, the time correction program 35) sequentially outputs time information (for example, display time) for each correction time information (for example, correction time data 43) acquired by the correction time information acquisition unit. Compared with the data 44), a configuration for judging is provided.

The correction time information (for example, correction time data 43) is a GPS signal selected from a candidate position information satellite (for example, the GPS satellite 15a) by using a satellite signal transmitted from the position information satellite (for example, the GPS satellite 15a). Since the receiving unit (for example, the antenna 11) receives each satellite and is acquired based on the satellite time information (for example, GPS time) acquired from the satellite signal, the receiving unit (for example, the antenna 11) When the satellite signal is received, the information includes the propagation delay time depending on the distance between the candidate position information satellite (for example, the GPS satellite 15a) and the receiving unit (for example, the antenna 11).
However, in the present embodiment, the time information correction unit (for example, the time correction program 35) is always based on the correction time information (for example, the correction time data 43) advanced from the time information (for example, the display time data 44). The time information (for example, display time data 44) is corrected. For this reason, it is a time measuring device with a time adjusting device (for example, GPS wristwatch 10) that can correct time information at a more accurate time with a small propagation delay time.

As described above, the GPS wristwatch 10 according to the present embodiment has a small propagation delay time, that is, a satellite signal transmitted from the nearest GPS satellite 15a or the like by the above-described process even when one satellite is captured. The display time data can be corrected by the correction time data 43 shown in FIG. 5 based on the satellite time information. Finally, the fixed propagation delay time data 42 of FIG. 5 is added and corrected, so that a more accurate time is displayed on the dial 12 of the GPS wristwatch 10.
Since the above-described steps are sequentially performed for each GPS satellite 15a, etc., it is possible to correct the time accurately using satellite signals from a single GPS satellite 15a, etc., and to consume power at a time. Can be suppressed.

Each of the above-described embodiments has been described with respect to GPS satellites. However, the present invention is not limited to GPS satellites, but is limited to other global navigation satellite systems (GNSS) such as Galileo and GLONASS, SBAS, A position information satellite such as a zenith satellite that transmits a radio signal that is a satellite signal including time information may be used. Alternatively, a radio wave signal including time information such as a long wave standard radio wave may be used.
The present invention is not limited to the above-described embodiments.

It is the schematic which shows the wristwatch with a GPS time correction apparatus which is a time measuring apparatus with a time correction apparatus which concerns on this invention, for example. It is the schematic which shows the main hardware constitutions etc. inside the wristwatch with a GPS time correction apparatus of FIG. FIG. 2 is an overall schematic diagram illustrating a main software configuration and the like of the wristwatch with a GPS time correction device in FIG. 1. 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 main operation | movement etc. of the wristwatch with a GPS time correction apparatus concerning this Embodiment. It is a schematic explanatory drawing which shows the satellite signal of a GPS satellite. It is a schematic explanatory drawing for demonstrating the orbit of a GPS satellite which is an example of a wristwatch with a GPS time correction device and a position information satellite.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wristwatch with GPS time correction device, 11 ... Antenna, 12 ... Dial, 13 ... Hand, 14 ... Display, 15a to 15d ... GPS satellite, 16 ... IF . IO. Power line, 17 ... CPU, 18 ... RAM, 19 ... ROM, 20 ... Filter (SAW), 21 ... RF, 22 ... Baseband (BB), 23 ... Real time Clock (RTC), 24 ... Crystal oscillation circuit with temperature compensation circuit (TCXO), 25 ... Control unit, 30 ... Various program storage unit, 31 ... GPS satellite scan program, 32 ... etc. Satellite acquisition determination program, 33 ... GPS satellite time data acquisition program, 34 ... correction time information determination program, 35 ... time correction program, 36 ... display time correction program, 40 ... various data storage , 41... GPS satellite scan data, 42... Fixed propagation delay time data, 43... Correction time data, 44. ... Modify number of times count data

Claims (7)

A candidate satellite selector for selecting a candidate location information satellite from a plurality of location information satellites;
A receiver that receives the satellite signals transmitted from a plurality of the position information satellites for each of the candidate position information satellites;
A correction time information acquisition unit that acquires at least satellite time information from the satellite signal received by the reception unit, and acquires correction time information based on the satellite time information;
A time information generator for generating time information;
A correction time information determination unit that compares the correction time information with the time information to determine whether the correction time information is ahead of the time information;
Based on the determination result of the correction time information determination unit, among the correction time information, a time information correction unit comprising a configuration for correcting the time information based on the correction time information that is relatively advanced,
A time correction apparatus comprising: The correction time information acquisition unit has a configuration for acquiring the correction time information based on the satellite time information for each satellite signal of the candidate position information satellite received by the reception unit,
The said correction time information determination part is provided with the structure which compares with the said time information in order for every said correction time information acquired in the said correction time information acquisition part, and determines it. Time correction device.   When the receiving unit first receives the satellite signal from the candidate position information satellite, the time information correcting unit is based on the satellite time information included in the first received satellite signal. The time correction apparatus according to claim 1, further comprising a configuration that is corrected by the corrected time information. After the receiving unit receives the satellite signal from the candidate position information satellite, it further includes a position information satellite determination unit that determines another candidate position information satellite that can be received from a plurality of the position information satellites,
If the time information correction unit determines that there is no candidate position information satellite that can be received by the position information satellite determination unit after correcting the time information based on the correction time information, a fixed propagation delay 4. The time correction apparatus according to claim 1, wherein the time correction apparatus has a configuration for correcting time. The location information satellite is a GPS (Global Positioning System) satellite,
The time correction apparatus according to claim 4, wherein the fixed propagation delay time is a propagation delay time of the satellite signal transmitted from the position information satellite located in the zenith direction from the receiving unit. A candidate satellite selector for selecting a candidate location information satellite from a plurality of location information satellites;
A receiver that receives the satellite signals transmitted from a plurality of the position information satellites for each of the candidate position information satellites;
A correction time information acquisition unit that acquires at least satellite time information from the satellite signal received by the reception unit, and acquires correction time information based on the satellite time information;
A time information generator for generating time information;
A correction time information determination unit that compares the correction time information with the time information and determines whether the correction time information is ahead of the time information;
Based on the determination result of the correction time information determination unit, among the correction time information, a time information correction unit comprising a configuration for correcting the time information based on the correction time information that is relatively advanced,
A time measuring device with a time adjustment device characterized by comprising: A candidate satellite selector for selecting a candidate location information satellite from a plurality of location information satellites;
A receiver that receives the satellite signals transmitted from a plurality of the position information satellites for each of the candidate position information satellites;
A correction time information acquisition unit that acquires at least satellite time information from the satellite signal received by the reception unit, and acquires correction time information based on the satellite time information;
A time information generator for generating time information;
A correction time information determination unit that compares the correction time information with the time information to determine whether the correction time information is ahead of the time information;
Based on the determination result of the correction time information determination unit, among the correction time information, a time information correction unit comprising a step of correcting the time information based on the correction time information that is relatively advanced,
A time correction method characterized by comprising:

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