JP2012173189A - Positioning device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning device of a satellite positioning system which lightens the mental burden on a user who waits for positioning to end by reporting a time that the positioning device requires for positioning to the outside.SOLUTION: The positioning device which performs positioning based upon a positioning signal received from a satellite includes: first calculation means 10 of calculating a range in which the positioning signal is searched for; second calculation means 11 of calculating a step of searching for the positioning signal; third calculation means 12 of calculating a time for integrating the positioning signal; fourth calculation means 13 of calculating a predicted necessary time up to the completion of the positioning calculation using the first calculation means 10, second calculation means 11, and third calculation means 12; timer means 14 of starting time management based upon the predicted necessary time calculated by the fourth calculation means 13 as an initial value; and reporting means 15 of reporting the predicted necessary time managed by the timer means 14.

Description

  The present invention relates to a positioning device and an electronic device that perform positioning by receiving positioning signals from satellites such as GPS (Global Positioning System).

  There are devices that can receive signals from satellites of satellite positioning systems such as GPS, perform positioning calculations, and provide position information. Specific examples include a mobile phone, a digital camera, and a PND (Portable Navigation Device).

  Depending on the initial conditions of the GPS positioning device and the signal reception environment, the time required for GPS positioning changes. The initial conditions of the GPS positioning device are, for example, the accuracy and reliability of the initial position, the accuracy and reliability of the error information of the GPS positioning device clock, whether or not the satellite has effective navigation data, etc. is there. Signal reception environments include open sky environments, indoor environments, and multipath environments.

  When initial conditions are disadvantageous or when positioning is performed in a place where radio wave reception sensitivity is low, the time required to complete positioning increases. In such a case, ingenuity is necessary so as not to impair the convenience of the user.

  For example, Patent Document 1 proposes a method in which the GPS positioning is stopped halfway based on the number of captured satellites so that the user does not wait more than necessary until the GPS positioning is completed.

JP 2008-249723 A

  However, in Patent Document 1, there is a case where GPS positioning is unilaterally stopped against the user's intention. Comparing the position accuracy by base station-based positioning and the position accuracy by GPS positioning, the latter is generally better. Depending on the purpose of use of the GPS positioning device, it may be desired to obtain a position as accurate as possible even if it takes some time. In such a case, if the GPS positioning is unilaterally stopped, it will be inconvenient for the user.

  An object of the present invention is to reduce the psychological load of waiting by providing a user with an accurate waiting time until positioning is completed. If the user can acquire an accurate waiting time, the user can freely select whether to wait until the positioning is completed or to cancel the positioning. In addition, if the user knows the exact waiting time, there is also an advantage that the feeling of being waited is reduced.

  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 positioning device that performs positioning based on a positioning signal received from a satellite according to this application example includes first calculation means for calculating a range for searching for the positioning signal, and a step for searching for the positioning signal. The positioning calculation is completed using the second calculating means for calculating, the third calculating means for calculating the time for integrating the positioning signals, the first calculating means, the second calculating means, and the third calculating means. Fourth calculation means for calculating the estimated required time until the time, timer means for starting time management with the estimated required time calculated by the fourth calculation means as an initial value, and the prediction managed by the timer means And notifying means for notifying the required time.

  According to this application example, since the user of the positioning device can acquire the time calculated by the fourth calculation means using the notification means, the user knows during the positioning execution how many seconds should be waited until the positioning is completed. As a result, it is possible to reduce the psychological burden of being awaited and to decide whether to continue positioning or to cancel the positioning at the user's will.

  Application Example 2 In the positioning device according to the application example, the fourth calculation means includes clock error information of the positioning device, initial position information of the positioning device, time error information of the positioning device, and When at least one of the orbit data of at least one or more satellites held by the positioning device to be used for satellite position calculation is updated, the estimated required time is calculated, and the timer means includes: When the estimated required time is updated by the fourth calculation means, time management is started using the estimated required time as an initial value.

  According to this application example, the clock error information of the positioning device, the initial position information of the positioning device, the time error information of the positioning device, and the satellite position calculation, which affect the time until the positioning calculation is completed, are used. In order to calculate the estimated required time when at least one of the satellite orbit data for the satellite is updated, the estimated required time is updated in synchronization with the occurrence of the state transition of the process in which the positioning device captures the satellite signal. Thus, it becomes possible to maintain the reliability of the estimated required time until the completion of positioning notified to the user in a high state.

  Application Example 3 In the positioning device according to the application example, the fourth calculation unit calculates the estimated required time when the search of all search ranges related to at least one of the satellites is completed, and the timer unit Is characterized in that, when the predicted required time is updated by the fourth calculation means, time management is started with the predicted required time as an initial value.

  If the satellite signal could not be acquired even though the entire search range was searched, at least one review of the search range and integration time that affects the time until the positioning calculation is completed will be performed. There is a high possibility that the estimated required time will be longer.

  According to this application example, in order to calculate the estimated required time in such a case, the estimated required time is updated in synchronization with the update of the search range and the accumulated time, and thereby the positioning notified to the user. It becomes possible to maintain the reliability of the estimated required time until completion in a high state.

  Application Example 4 In the positioning device according to the application example described above, the fourth calculation means includes at least one of reception sensitivity of the positioning signal, reception stability of the positioning signal, and the number of captured satellites. The estimated required time is filtered using one of them.

  In an environment where the reception sensitivity of the positioning signal is low, such as an indoor environment, the positioning result may not be immediately notified to the user even if the positioning signal can be captured. Positioning results in environments where reception sensitivity is low often deviate greatly from the true position.For example, if you store the positioning results for several seconds and those positions are roughly the same, notify the user, Various measures are taken to wait until a sufficient number of satellites have been acquired to improve the positioning accuracy.

  According to this application example, the estimated time required to reflect the positioning environment can be calculated in order to take into account the processing time for securing the position accuracy in the indoor environment, depending on the positioning environment. It becomes possible to maintain the reliability of the estimated required time until the completion of positioning to be notified in a high state.

  Application Example 5 In the positioning device according to the application example described above, the notification unit notifies at least one of character information, voice information, and graphical user interface information.

  According to this application example, the user can obtain the estimated required time by any one or a combination of two or more of character information, voice information, and graphical user interface information. A flexible response becomes possible, and this makes it possible to improve the ease of use of the positioning device.

  Application Example 6 An electronic apparatus according to this application example includes the positioning device described in any one of the above.

  According to this application example, an electronic apparatus having a positioning device that can reduce a psychological load of being awaited and can determine whether to continue or stop positioning at the user's will. Can be provided.

The block diagram of the GPS positioning apparatus which concerns on this embodiment. Schematic explanatory drawing of the signal search range calculation means concerning this embodiment. Schematic explanatory drawing of the signal search step calculation means according to the present embodiment. Schematic explanatory drawing of the signal integration time calculation means concerning this embodiment. The schematic explanatory drawing of the estimated required time notification means which concerns on this embodiment. The schematic explanatory drawing of the estimated required time notification means which concerns on this embodiment.

  A GPS positioning device as a positioning device according to the present embodiment will be described based on the drawings. The GPS positioning device receives a positioning signal from a GPS satellite of the satellite positioning system.

(1) Overall Configuration of GPS Positioning Device FIG. 1 is a configuration diagram of a GPS positioning device according to the present embodiment. As shown in FIG. 1, the GPS positioning apparatus 2 according to the present embodiment includes a signal search range calculation means (first calculation means) 10, a signal search step calculation means (second calculation means) 11, and a signal integration time calculation. A means (third calculation means) 12, a predicted required time calculation means (fourth calculation means) 13, a timer means 14, and a predicted required time notification means (notification means) 15 are provided. The signal search range calculation means 10 calculates a range for searching for positioning signals. The signal search step calculation means 11 calculates a step for searching for a positioning signal. The signal integration time calculation means 12 calculates the time for integrating the positioning signals.
The GPS positioning device 2 is a mobile phone having a GPS positioning function that includes a communication unit 16. The communication unit 16 is used to communicate with an external assist server to acquire assist data necessary for positioning, and to notify the positioning result to the outside.

  The estimated required time calculation means 13 uses the signal search range calculation means 10, the signal search step calculation means 11 and the signal integration time calculation means 12 to calculate how much time is left until the positioning is completed. The estimated required time calculation means 13 is a GPS positioning device for use in clock error information of the GPS positioning device 2, initial position information of the GPS positioning device 2, time error information of the GPS positioning device 2, and position calculation of GPS satellites. When at least one of the orbit data of at least one GPS satellite held by the device 2 is updated, the time required for completing the positioning calculation may be calculated. Thereby, the clock error information of the GPS positioning device 2, the initial position information of the GPS positioning device 2, the time error information of the GPS positioning device 2, and the GPS satellite position calculation that affect the time until the positioning calculation is completed. In order to calculate the estimated time required when at least one of the GPS satellite orbit data to be used for the update is updated, the GPS positioning device 2 requires the prediction in synchronization with the occurrence of the state transition of the process of capturing the satellite signal. The time will be updated, which makes it possible to maintain the reliability of the estimated required time until the completion of positioning notified to the user in a high state. The estimated required time calculation means 13 may calculate the time required for completing the positioning calculation when the search of the entire search range for at least one GPS satellite is completed. As a result, if the satellite signal cannot be acquired even though the entire search range has been searched, at least one review of the search range and integration time that affects the time until the positioning calculation is completed is performed. Therefore, the estimated required time is calculated when the possibility that the predicted required time becomes long is high. As a result, it is possible to maintain the reliability of the estimated required time until the completion of positioning notified to the user in a high state. The estimated required time calculation means 13 filters the time required for completing the positioning calculation using at least one of the positioning signal reception sensitivity, the positioning signal reception stability, and the number of captured GPS satellites. It may be processed. As a result, the estimated time required to reflect the positioning environment can be calculated to take into account the processing time required to ensure location accuracy in the indoor environment, depending on the positioning environment, thereby completing the positioning to notify the user. It is possible to maintain the reliability of the estimated required time up to a high level.

  The timer means 14 counts down the time until the positioning is completed with the time calculated by the estimated required time calculating means 13 as an initial value. When the predicted required time is updated by the predicted required time calculating means 13, the timer means 14 may start time management with the predicted required time as an initial value. As a result, the estimated required time is updated in synchronization with the update of the search range and accumulated time, and thereby, the reliability of the estimated required time until the completion of positioning notified to the user can be maintained in a high state. It becomes possible.

  The predicted required time notifying unit 15 notifies the user of the predicted required time until the completion of positioning managed by the timer unit 14. The estimated required time notification means 15 may notify at least one of character information, voice information, and graphical user interface information. As a result, the user can acquire the estimated required time by any one or a combination of two or more of character information, voice information, and graphical user interface information, so that it is flexible to the detailed specifications of the GPS positioning device 2. This makes it possible to improve the usability of the GPS positioning device 2.

  In a general GPS positioning device, the information that can be acquired until the positioning calculation is completed is limited to the reception sensitivity (SNR) and satellite arrangement of the captured GPS satellite during the acquisition process. The user can only wait until the positioning result is obtained. In particular, in an indoor environment or the like, it may take one minute or more from signal capture to completion of positioning calculation, and the psychological burden on the user who is waiting for positioning is never small.

  The time required for positioning can be shortened by improving the performance of the GPS positioning device. However, the relationship is that the lower the reception sensitivity, the longer the time required for positioning. On the other hand, the GPS positioning device 2 according to the present embodiment is characterized by reducing the psychological burden of waiting for positioning by accurately transmitting the time required for positioning to the user as much as possible. To do.

(2) Calculation of Signal Search Range FIG. 2 is a schematic explanatory diagram of the signal search range calculation means 10 according to this embodiment. In order to calculate the time required for positioning, it is necessary to first determine the range in which the GPS signal is searched. A range in which a GPS signal is searched is called a signal search range. The signal search range is different for each GPS satellite. For example, as shown in FIG. 2, the signal search range 20 of the satellite A and the signal search range 21 of the satellite B are different. The signal search range mainly depends on the initial position reliability of the GPS positioning device 2 and the magnitude of the error of the internal clock of the GPS positioning device 2.

  First, the relationship between the signal search range and the reliability of the initial position information will be described. A GPS satellite (not shown) transmits a signal using a carrier wave of 1575.42 MHz (L1 frequency). Since the GPS satellite is constantly moving when viewed from the GPS positioning device 2, a Doppler effect occurs between the GPS satellite and the GPS positioning device 2. Due to the Doppler effect, the frequency of the carrier wave observed by the GPS positioning device 2 is different from 1575.42 MHz transmitted by the GPS satellite. Therefore, in order to capture the GPS signal, it is necessary to calculate how many MHz the observation frequency is due to the Doppler effect.

  The observation frequency affected by the Doppler effect is determined depending on the relative speed between the GPS satellite and the GPS positioning device 2. In order to calculate the relative velocity, the respective positions and velocities of the GPS satellite and the GPS positioning device 2 are necessary. The position and velocity of the GPS satellite can be obtained from orbit data (ephemeris or almanac) of the GPS satellite. On the other hand, the position and speed of the GPS positioning device 2 cannot be acquired when the signal is captured. The accurate position and speed of the GPS positioning device 2 can be acquired only after the positioning calculation is completed.

  For this reason, the GPS positioning device 2 calculates a signal search range in consideration of the Doppler effect based on the initial position information indicating the approximate position of the GPS positioning device 2. If it is accurate initial position information (initial position information with high reliability), an accurate Doppler effect can be calculated, and therefore the search range may be narrow. Conversely, if the initial position information is not accurate, the search range must be widened accordingly. For example, when the initial position reliability is 1000 km (meaning that there is a true position somewhere inside a circle with a radius of 1000 km), it is necessary to search the range of 1800 Hz.

  Next, the relationship between the signal search range and the error of the internal clock (sometimes called a master clock) of the GPS positioning device 2 will be described. The GPS positioning device 2 generates a GPS signal replica signal using an internal clock in order to capture the GPS signal. Then, a correlation operation between the received signal and the replica signal is performed to find a place where the correlation value reaches a peak.

  In general, the internal clock is often a TCXO (Temperature Compensated Crystal Oscillator). However, the accuracy of the TCXO clock is far inferior to that of an atomic clock mounted on a GPS satellite. The accuracy of the internal clock affects the accuracy of the replica signal. An error is included in the replica signal generated using the internal clock including the error. Then, the error of the replica signal is observed as a deviation of the observation frequency. On the other hand, the error of the internal clock can be obtained as a result of the positioning calculation.

  What is important here is that a general GPS positioning device cannot distinguish between a shift in observation frequency caused by an error of the internal clock and a shift in observation frequency caused by the Doppler effect. In other words, the observed frequency of the GPS signal observed by the GPS positioning device 2 includes a mixture of an internal clock error of the GPS positioning device 2 and an influence due to the Doppler effect.

  The error of the internal clock is expressed by a combination of the oscillation frequency and reliability information indicating how many ppm of error is based on the frequency. Similar to the reliability of the initial position information, if the reliability of the error information of the internal clock is high, the search range may be narrow. Conversely, if the reliability of the error information of the internal clock is low, the search range must be widened.

(3) Calculation of Signal Search Step The GPS positioning device 2 performs a correlation operation between the received signal and the replica signal and searches for a correlation value peak. In order to find the peak of the correlation value, it is necessary to obtain correlation values at a plurality of points while gradually shifting the timing of the received signal and the replica signal. In order to perform such correlation calculation, a large amount of hardware resources such as a memory are required. However, considering the size and cost of the GPS chip, it is difficult to secure a large amount of memory.

  FIG. 3 is a schematic explanatory diagram of the signal search step calculation unit 11 according to the present embodiment. In order to acquire a signal using limited hardware resources, a method of performing a search by dividing a search range finely as shown in FIG. 3 is generally used. The divided search range is called a search step. The size of the search step varies depending on the purpose of the search. If it is desired to complete the search of the entire search range quickly, the search step 31 may be enlarged. Further, since it may take some time, the search step 30 may be made small when it is desired to perform a careful search.

  Depending on the receiving environment, the size of the search step may be changed. When the reception sensitivity is high, the correlation value is high, so that a signal can be captured even if the search step is large (coarse search). When the reception sensitivity is low, the correlation value is low, so that the signal cannot be captured unless the search step is made small and a careful search is performed.

  As described above, the GPS positioning device 2 calculates an appropriate search step according to the purpose of the search and the reception environment, and performs the search. For example, if the search range is 300 Hz, the search step is 25 Hz, and execution of one search step takes 2 seconds, it takes (300 ÷ 25) × 2 = 24 seconds to search the entire search range.

  In this example, it is unknown where the GPS signal is in the 300 Hz range. If you are lucky, you may be able to capture the signal in the first search step, or you may be unlucky and capture the signal up to the last search step. The signal acquisition time is 2 seconds for the former and 24 seconds for the latter. However, since at least four or more GPS satellites are required to perform positioning calculation, the probability that acquisition of these four or more GPS satellites is luckily completed in 2 seconds is quite low. Conversely, it can be guaranteed to the user that the search is completed within at least 24 seconds.

(4) Calculation of signal integration time FIG. 4 is a schematic explanatory diagram of the signal integration time calculation means 12 according to the present embodiment. In an environment where the signal reception sensitivity is low, such as an indoor environment, in order to find the peak of the correlation value, an integration process of adding several correlation values is performed. In an indoor environment or the like, it becomes difficult to distinguish between noise and GPS signals. In other words, the SNR (Signal-Noise Ratio) is low. Since the noise is irregular (random), it can be canceled by taking the sum of the correlation values. On the other hand, since the GPS signal has regularity, the larger the sum of the correlation values, the larger the value (a peak appears).

  In general, the GPS positioning device 2 cannot know the positioning environment before starting the positioning. Therefore, as shown in FIG. 4, for example, first, a 1-second integration 40 is performed, and if the signal cannot be captured, a 2-second integration 41 is performed next, and if it cannot be captured, a 4-second integration 42 is performed. The integration time is gradually increased.

(5) Notification Method for Estimated Required Time FIGS. 5 and 6 are schematic explanatory diagrams of the estimated required time notification means 15 according to the present embodiment. There are various variations in the method of notifying the user of the GPS positioning device 2 how long the positioning is completed. In a device having a display device such as a mobile phone, a PND, or a digital camera, a method that effectively uses the display device may be employed. For example, as shown in FIG. 5, a GUI such as a progress bar indicating the search range vertically and the elapsed search time as shown in FIG. 5 may be used. Further, as shown in FIG. 6A, character information and a GUI may be combined. In a device with a speaker device, notification may be made using sound as shown in FIG. Furthermore, notification may be performed by combining character information, GUI, and voice.

  Next, update of the estimated required time will be described. The estimated required time until the positioning is completed can be determined mainly depending on the signal search range, the signal search step, and the signal search time. These depend on the clock error information of the GPS positioning device 2, the initial position information of the GPS positioning device 2, the time error information of the GPS positioning device 2, and the orbit data of the GPS satellites held by the GPS positioning device 2.

  The clock error information of the GPS positioning device 2 is often updated during positioning. If these pieces of information that affect the estimated required time are updated, it is necessary to update the estimated required time in order to maintain the reliability of the estimated required time notified to the user.

(1) Updating the clock error information of the GPS positioning device 2 The GPS positioning device 2 has several methods for improving the accuracy of the clock error information. There are two methods. One is a method of calculating or correcting a clock error inside the GPS positioning device with reference to an accurate external clock. The other is a method of capturing a GPS satellite signal and calculating or correcting a clock error in the GPS positioning device 2 based on the signal.

  As an example of calculating the clock error inside the GPS positioning device 2 on the basis of an external accurate clock, there is one using a clock synchronized with a base station of a mobile phone. When the mobile phone communicates with the base station of the mobile phone, it is synchronized with the clock of the base station. The base station has an extremely accurate clock as compared with the GPS positioning device 2. Therefore, a highly accurate clock possessed by the base station can be used inside the mobile phone synchronized with the base station. In a mobile phone with a built-in GPS function, the clock error of the GPS positioning device 2 can be calculated using the base station clock. Therefore, in this example, the clock error information of the GPS positioning device 2 is updated at a timing that can be synchronized with the clock of the mobile phone base station.

  Next, an example of capturing a GPS satellite signal and calculating a clock error in the GPS positioning device 2 based on the signal will be described. GPS satellites use atomic clocks to transmit very accurate carriers. If there is no Doppler effect, the frequency of the signal received by the GPS positioning device 2 is equal to the frequency of the signal transmitted by the GPS satellite. What is important at this time is that the replica signal is generated using a clock including an error in the GPS positioning device 2, so that the “apparent frequency” of the received signal is the frequency of the signal transmitted by the GPS satellite. Is different. This frequency shift is caused by an error of the internal clock. The clock error in the GPS positioning device 2 can be calculated using this frequency shift.

  Actually, there is a Doppler effect between the GPS positioning device 2 and the GPS satellite. However, if there is an accurate initial position of the GPS positioning device 2 (for example, an initial position reliability of about 10 km) and a GPS satellite position and velocity that can be calculated using the ephemeris, the received frequency deviation due to the Doppler effect is obtained. The shift can be estimated with high accuracy. Therefore, even if there is a Doppler effect, the clock error inside the GPS positioning device 2 can be calculated using the received signal as described above.

(2) Updating the initial position information of the GPS positioning device 2 For the GPS positioning device 2, the more accurate the initial position information, the more advantageous the positioning. The initial position information is used for calculation of a pseudo distance between the GPS positioning device 2 and a GPS satellite, calculation of a signal search range (calculation of Doppler effect), and the like. How to obtain accurate initial position information is one of the problems for the GPS positioning device 2, but if the GPS positioning device 2 is compatible with A-GPS (Assisted-GPS), the accurate initial position is obtained from the server. Information can be acquired. Since communication with the server takes time, a difference often occurs between the timing of starting positioning and the timing of acquiring initial position information. Therefore, if the initial position information is updated, the predicted required time needs to be updated in order to maintain high reliability of the predicted required time notified to the user.

(3) Updating the time error information of the GPS positioning device 2 As with the initial position information, the GPS positioning device 2 can advantageously perform positioning as the time error information is more accurate. In order to perform positioning with the GPS positioning device 2, it is necessary to calculate the exact position and velocity of the GPS satellite. The position and velocity of the GPS satellite are elements necessary for calculating the Doppler effect. The position and velocity of the GPS satellite can be calculated using the ephemeris, but it is necessary to give time information as an input for the calculation. If the time error is large, the correct position and velocity of the GPS satellite cannot be calculated, which adversely affects positioning.

  If the GPS positioning device 2 is compatible with A-GPS, accurate time information can be acquired from the server. Since there is an influence of the communication time with the server, the accuracy of the time information that can be acquired in this case is within a few seconds with respect to the GPS time. In addition, similar to the initial position information, there is often a difference between the timing of starting positioning and the timing of acquiring time information from the server.

  If accurate time information synchronized with GPS time is to be acquired by the GPS positioning device 2, Z-Count (Z count) included in the navigation data (NavData) may be decoded. However, in order to be able to decode the navigation data, a certain degree of reception sensitivity is required, so that it is difficult to decode Z-Count in an indoor environment.

  Thus, the time error information of the GPS positioning device 2 may be updated during positioning. As the time error information is updated, the internal state of the GPS positioning device 2 changes. Therefore, in order to maintain the reliability of the estimated required time notified to the user, it is necessary to update the estimated required time.

(4) Update of orbit data of GPS satellites held by the GPS positioning device 2 In order for the GPS positioning device 2 to search for satellite signals and perform positioning calculations, it is necessary to determine the exact position and velocity of the GPS satellites. There is. The exact position and velocity of the GPS satellite can be calculated using the ephemeris broadcast by the GPS satellite. The approximate position and speed of the GPS satellite can be calculated using the almanac broadcasted by the GPS satellite. Also, Extended Ephemeris can be used to calculate the exact position and velocity of GPS satellites. The effective period of the ephemeris being broadcast is 4 hours, but the effective period of the extended ephemeris is as long as several days to one week.

  There are at least two methods by which the GPS positioning device 2 acquires ephemeris and almanac broadcast from GPS satellites. One is a method in which the GPS positioning device 2 acquires and decodes a GPS signal by itself. The other is a method in which the GPS positioning device 2 that supports A-GPS acquires from the server using the communication unit 16. In either method, orbit data is often acquired during positioning and orbit data is updated. When the orbit data is updated, the position and speed of the GPS satellite are updated. The position and speed of the GPS satellite affect the search range of the GPS signal. Therefore, when the trajectory data is updated, it is necessary to update the predicted required time in order to maintain high reliability of the predicted required time notified to the user.

  Even if the GPS positioning device 2 can capture the GPS signal, it cannot always execute the positioning calculation. In particular, in the case of positioning in an environment where reception sensitivity is low, such as an indoor environment, in order to improve the accuracy of the positioning position, signal stability and positioning result check (scrutiny) are performed. This examination requires a time of several seconds, and a longer time is required as the reception sensitivity is lower. In order to further increase the reliability of the estimated required time notified to the user, it is necessary to consider this time.

  As a method for taking this time into account, there is a filtering process such as a weighting process according to the reception sensitivity and reception stability of the captured GPS satellite and the number of captured satellites. The filter can be realized by acquiring the performance characteristic data of the positioning device at the time of designing the GPS positioning device 2 and determining the configuration and parameters of the filter suitable for the characteristic.

  According to the present embodiment, the user of the GPS positioning device 2 can acquire the time calculated by the predicted required time calculating means 13 using the predicted required time notifying means 15, so how many seconds should be waited for completion of positioning. It becomes possible to know whether it is good while performing positioning, thereby reducing the psychological burden of waiting, and determining whether to continue positioning or stop at the user's will It becomes possible.

  The present invention can also be applied to an electronic device having a GPS positioning function other than a mobile phone. You may apply to a digital camera, a clock, a personal computer, a GPS logger, etc.

  2 ... GPS positioning device (positioning device), 10 ... signal search range calculation means (first calculation means), 11 ... signal search step calculation means (second calculation means), 12 ... signal integration time calculation means (third calculation means) ), 13 ... Predicted required time calculating means (fourth calculating means), 14 ... Timer means, 15 ... Predicted required time notifying means (notifying means), 16 ... Communication unit, 20, 21 ... Signal search range, 30, 31 ... Search step, 40, 41, 42...

Claims (6)

A positioning device that performs positioning based on a positioning signal received from a satellite,
First calculating means for calculating a range for searching the positioning signal;
Second calculating means for calculating the step of searching for the positioning signal;
Third calculation means for calculating the time for integrating the positioning signals;
Fourth calculation means for calculating a predicted required time until the positioning calculation is completed using the first calculation means, the second calculation means, and the third calculation means,
Timer means for starting time management with the estimated required time calculated by the fourth calculation means as an initial value;
Notification means for notifying the estimated required time managed by the timer means;
A positioning device comprising: The fourth calculation means is held by the positioning device to be used for clock error information of the positioning device, initial position information of the positioning device, time error information of the positioning device, and position calculation of the satellite. Calculating at least one of the estimated time required when at least one of the orbit data of the at least one satellite is updated;
The timer means starts time management with the estimated required time as an initial value when the estimated required time is updated by the fourth calculating means,
The positioning device according to claim 1. The fourth calculation means calculates the estimated required time when the search of the entire search range for at least one of the satellites is completed,
The timer means starts time management with the estimated required time as an initial value when the estimated required time is updated by the fourth calculating means,
The positioning device according to claim 1. The fourth calculation means filters the estimated required time using at least one of reception sensitivity of the positioning signal, reception stability of the positioning signal, and the number of captured satellites. Features
The positioning device according to any one of claims 1 to 3. The notification means notifies at least one of character information, voice information, and graphical user interface information,
The positioning device according to any one of claims 1 to 4.   An electronic apparatus comprising the positioning device according to claim 1.

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