JP4292682B2 - GPS receiver, GPS positioning method, and storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a GPS (Global Positioning System) used for a navigation system in a moving body such as a car navigation system, and can obtain position data even at a time before starting positioning after starting. The present invention relates to a receiver, a storage medium, and a GPS positioning method.
[0002]
[Prior art]
The GPS system is a position measurement system that has been developed so that mobile objects such as cars, aircraft, and ships can obtain the position and movement speed on the earth in real time using GPS satellites with the orbit in the sky. Recently, besides the positioning by this moving body, it is widely used in the field of static surveying for measuring the distance and direction between certain points on the earth. When such a GPS system is used, a GPS receiver for receiving radio waves transmitted from GPS satellites is used.
[0003]
FIG. 6 is an explanatory diagram showing a schematic configuration of a commonly used GPS system. As shown in FIG. 6, a spectrum spread 1.557542 GHz signal is transmitted from the GPS satellite 200. This transmitted signal is received by the antenna unit 211 of the GPS receiver 210 after a propagation time corresponding to the distance. The signal received by the antenna unit 211 is down-converted to a predetermined intermediate frequency by the intermediate frequency converter 212 and enters the signal synchronous demodulation unit 213. Thereafter, the signal synchronous demodulator 213 despreads the signal and demodulates the data. The demodulated data is used by the positioning calculation unit 214 for positioning calculation. In this way, a signal transmitted from the GPS satellite 200 is received by the GPS receiver 210, and positioning calculation is performed.
[0004]
FIG. 7 shows a conventional GPS positioning operation performed by the GPS receiver 210. In this figure, the horizontal axis represents the elapsed time after the GPS receiver 210 is powered on (started up). First, when the power is turned on (ON), a signal is received from each of a plurality of GPS satellites that can be captured at that time, and a channel is assigned to each of the GPS satellites (in the example of FIG. 7, The allocated channels are exemplified in Ch.1 to Ch.4). In each channel, the data from each GPS satellite is demodulated. Here, as shown in FIG. 7, the signal synchronous demodulator 213 performs (a) spectrum despreading and data demodulation, The positioning calculation unit 214 sequentially performs (b) subframe synchronization by specifying the preamble and (c) capturing trajectory parameters from the subframe. In each channel, when (c) orbital parameter acquisition is completed, (d) positioning calculation is possible, but the positioning calculation unit 214 normally has four or more channels. The positioning calculation is started when the acquisition of the trajectory parameters in (c) is completed (at the time point X in the figure). When the positioning calculation is completed, positioning data is output and finally the current position is calculated.
[0005]
[Problems to be solved by the invention]
In the conventional GPS receiver and the GPS positioning method, it takes about 30 seconds until the positioning is possible after the apparatus is started. This takes about 5 seconds for (b) spectrum despreading and data demodulation, (b) about 10 seconds for subframe synchronization, and (c) the relationship of the data frame arrangement to capture trajectory parameters. This is because it takes about 20 seconds.
[0006]
For this reason, conventionally, the trajectory parameters obtained during the previous startup are stored in the nonvolatile memory, and when the subframe synchronization of (b) is completed, the positioning calculation is started using the stored trajectory parameters. There is something like this. However, even in such a configuration, since a GPS satellite will die after a certain period of time (for example, about 2 hours), the stored orbit parameters cannot be used after the apparatus has been stopped for a long time. Then, as described above, after starting the GPS receiver, positioning cannot be performed until the orbital parameter is acquired again, and it takes time until the positioning calculation is started.
[0007]
By the way, for example, some navigation systems have a function of storing GPS positioning results and utilizing them as movement trajectories or the like. In such a navigation system, for example, when the movement is started simultaneously with the start of the apparatus without waiting for the start of the positioning calculation, when the positioning is actually possible, the position has already moved to a position away from the starting point. I'm sorry. As a result, the vicinity of the starting point cannot be left as a movement trajectory, and there is a problem that the subsequent route setting is hindered.
[0008]
In addition, various portable terminals such as recent digital cameras have appeared in which a GPS receiver is built in or connected to utilize position data. For example, a digital camera is equipped with a GPS receiver, and shooting position data and the like are included in a captured image and recorded. In such a terminal, the current position cannot be quickly measured immediately after startup, so the image taken immediately after startup cannot include the data of the shooting position and must wait until positioning is possible. Was very inconvenient.
[0009]
The present invention has been made to solve such a technical problem, and the object of the present invention is to obtain positioning information at a time before starting actual positioning after startup. To provide a GPS receiver, a GPS positioning method, and a storage medium.
[0010]
[Means for Solving the Problems]
For this purpose, the GPS receiver of the present invention is a GPS receiver that performs positioning based on signals transmitted from a plurality of GPS satellites, a signal receiving means for receiving the signals from the GPS satellites, and the signal Range data acquisition means for acquiring range data from the signal received by the reception means, trajectory parameter acquisition means for acquiring trajectory parameters from the signal received by the signal reception means, and the trajectory parameters in the trajectory parameter acquisition means Range data storage means for storing the range data acquired by the range data acquisition means before being acquired, and position data corresponding to the range data stored in the range data storage means, the trajectory parameter acquisition means Position data calculation means for calculating based on the trajectory parameters captured in It is characterized in that.
Here, the range data is time data obtained from a signal transmitted from a GPS satellite. From each GPS satellite, a signal with a uniform timing is transmitted in all the GPS satellites, and this signal is a counter value that is reset at regular intervals. By simultaneously receiving this signal on the GPS receiver side, signal phase data between a plurality of GPS satellites at that time can be obtained, and the distance (range) between the GPS satellite and the GPS receiver can be obtained based on this data. it can. This range data can be obtained by receiving a signal, which is spectrum-spread and transmitted from a GPS satellite, on the GPS receiver side and starting to despread the spectrum.
On the other hand, the orbit parameter is also called ephemeris data and indicates detailed orbit information of each GPS satellite. In addition to the orbit parameters, the signals from each GPS satellite are encoded with pseudo-random noise that includes data frames containing predetermined data such as almanac data, which is rough orbit information mainly used for searching for GPS satellites. It has become a state. On the GPS receiver side, the received data signal is subjected to spectrum despreading and further data demodulation, whereby the data frame can be obtained, and orbital parameters are captured from the data frame. This data frame is composed of a long frame composed of five subframes, and one subframe has a 6-second period. In one long frame, trajectory parameters are stored in the fourth to fifth subframes. For this reason, even if a signal from a GPS satellite is received and demodulated, it takes up to 30 seconds to obtain orbital parameters.
As described above, it takes time until the orbital parameter is obtained after the GPS receiver starts to receive the signal, whereas the range data can be obtained immediately after the signal reception is started.
In such a GPS receiver, a signal from a GPS satellite is received by the signal receiving unit, and range data is acquired from the received signal by the range data acquiring unit. After that, the trajectory parameter capturing means starts capturing trajectory parameters from the signal, but in the range data storage means, the range data acquired by the range data acquiring means before the trajectory parameters are captured by the trajectory parameter capturing means. Is remembered. Then, the position data calculation means calculates position data corresponding to the range data stored in the range data storage means based on the trajectory parameters captured by the trajectory parameter capture means, before the start of capturing the trajectory parameters. Position data can be obtained.
Here, the method of using the obtained position data is not particularly limited.
[0011]
Further, as one form of using the obtained position data, in this GPS receiver, based on the position data calculated by the position data calculating means, before the orbit parameters are captured by the orbit parameter capturing means. Further, it is possible to provide a movement route generation means for generating movement route information of the GPS receiver. According to this configuration, in the navigation system or the like, the movement route generation unit generates movement route information of the GPS receiver, for example, a movement locus before the orbit parameter is captured by the orbit parameter capturing unit. Is possible.
[0012]
Furthermore, as another mode of using the obtained position data, in the GPS transmitter according to the present invention, the position data calculating means receives the GPS reception before the orbit parameter is captured by the orbit parameter capturing means. It is also possible to calculate position data when a predetermined operation is performed on the machine. With this configuration, when a predetermined operation, for example, a shooting operation is performed before the trajectory parameter is captured by the trajectory parameter capturing means in a digital camera or the like having a GPS function, for example, position data at that time Can be calculated by the position data calculation means. Therefore, by storing the calculated position data together with, for example, photographed image data, it is possible to incorporate the photographing position information in the photographed image.
[0013]
Further, when the GPS receiver of the present invention is grasped from another viewpoint, the GPS receiver of the present invention is a GPS receiver that performs positioning based on signals transmitted from a plurality of GPS satellites. , A positioning calculation unit that performs positioning calculation based on the signal received by the signal receiving unit, and before the positioning calculation is performed by the positioning calculation unit after starting the GPS receiver A position data generation unit that generates position data of the GPS receiver. If comprised in this way, after starting a GPS receiver in a position data generation part, the position data of the said GPS receiver before a positioning calculation is performed in a positioning calculation part can be produced | generated.
Here, the positioning calculation method in the positioning calculation unit, the position data generation method, and the like are not specifically limited.
[0014]
When the present invention is grasped by changing the category, the present invention receives signals from a plurality of GPS satellites and stores the range data from the time when the range data included in the received signals can be obtained. After the time when the trajectory parameter is captured from the received signal, the positioning calculation is performed based on the trajectory parameter and the stored range data, and the position before the trajectory parameter is captured. It can be characterized by determining data.
[0015]
Further, when the present invention is grasped as a recording medium, the recording medium of the present invention is a storage medium in which a program to be executed by a computer is stored so that the computer can read the program. The process of storing the range data from the start of the acquisition of the range data, and after capturing the orbit parameter from the signal from the GPS satellite, and corresponding to the stored range data based on the orbit parameter A process of generating position data indicating a position at a time point, and causing the computer to execute the process. According to this recording medium, the position at the time corresponding to the stored range data is acquired based on the orbit parameter after the orbit parameter is captured from the signal from the GPS satellite by causing the computer to execute the stored program. Can be generated.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is an explanatory diagram showing a schematic configuration of a GPS receiver in the present embodiment. As shown in FIG. 1, the GPS receiver in the present embodiment is a GPS antenna unit (signal receiving means, signal that receives a 1575.42 MHz signal (radio wave) transmitted from a GPS satellite at an altitude of about 20,000 km. (Receiving unit) 1, an intermediate frequency converter 2 for converting a signal received from the GPS antenna unit 1 to an intermediate frequency, and a demodulating unit (range) for demodulating the signal lowered to the intermediate frequency by the intermediate frequency converter 2 Data acquisition means) 3, a positioning calculation section (orbit parameter capturing means, position data calculation means, movement path generation means, position data generation section) 4 for extracting the necessary data from the demodulated signal and calculating the current position; Information obtained by positioning via the clock unit 5 and the display unit interface (I / F) 6 comprising a microcomputer or the like with a clock function for knowing the time on the GPS receiver side It is configured to include a display unit 7, such as a monitor for displaying.
[0017]
As shown in FIG. 2, the demodulator 3 includes a spectrum despreader 10 and a data demodulator 11, which have a plurality of channels and send signals sent from a plurality of GPS satellites to each GPS. Each satellite is assigned to one channel, and predetermined processing is performed.
[0018]
By the way, what is shown in FIG. 3 is a frame structure of a hierarchized signal (navigation message) sent from each GPS satellite. As shown in this figure, the long frame is composed of five subframes. 1 subframe = 10 words, 1 word = 30 data bits, 1 data bit is composed of 20 pseudo noise codes (C / A code), and one pseudo noise code is 1 [msec], so 1 data The bit is 20 [msec], 1 word is 600 [msec], 1 subframe is 6 [sec], and 1 long frame is 30 [sec]. One master frame is composed of 25 long frames, and transmission from a GPS satellite is continued with 12.5 [min] as one cycle.
[0019]
Each subframe starts with an 8-bit preamble (synchronization pattern). The TOW (Time Of Week) that represents the signal time up to 1 week with a 6-second cycle is stored from the 31st bit to the 17th bit, which is the second word of each subframe. I can know. Further, 3 bits from the 50th bit of each subframe indicate the ID of the subframe. From the count value and ID of these subframes, the signal transmission time in the GPS satellite can be known.
Further, orbit parameters (ephemeris data), which are detailed orbit information of GPS satellites, are stored in the first to third subframes, and information on all GPS satellites is stored in the fourth to fifth subframes. Almanac data, which is mainly used for searching for GPS satellites and is rough orbit information, is also stored here.
[0020]
The signal configured as described above has a bit rate of 50 [bps] and a bit period of 20 [msec]. The signal is transmitted from the GPS satellite in a state where the spectrum is spread by pseudo-random noise having a chip speed of 1.023 [MHz]. The code length (repetition period) of this pseudo random noise is 1 [msec], and 20 periods correspond to 1 bit of the signal. One chip period is approximately 1 [μsec].
[0021]
The spectrum despreader 10 demodulates only the signals of the assigned GPS satellites buried under the noise by multiplying each GPS satellite with a pseudo-random noise specific to each other and despreading and detecting the correlation. At this time, the signal transmitted by multiplying the pseudo-random noise from each GPS satellite is transmitted at a unified timing in all the GPS satellites, and this signal is repeated at regular intervals. The spectrum despreader 10 obtains range data by counting the pseudo-random noise chips of this signal. As a configuration for this purpose, a pseudo random noise controller (not shown) constituting the spectrum despreader 10 outputs a clock of 1.023 [MHz] synchronized with the chip speed of pseudo random noise. This clock is supplied as a count clock to a range counter (not shown) constituting the spectrum despreader 10. The pseudo random noise generator outputs an epoch signal synchronized with the repetition period of the pseudo random noise, and this epoch signal is supplied to the range counter as a reset signal. In the range counter, the pseudo-random noise chip is simultaneously counted in all channels every predetermined time, for example, 100 [msec], and the count value is output to the positioning calculation unit 4 as range data.
The range data can be obtained by receiving a signal, which is spectrum-spread and transmitted from a GPS satellite, on the GPS receiver side and starting spectrum despreading by the spectrum despreader 10.
As such a spectrum despreader 10, for example, a technique disclosed in Japanese Patent Laid-Open No. 4-237228 already filed by the present inventors is preferably used.
[0022]
The data demodulator 11 further demodulates the signal despread by the spectrum despreader 10 by the two-phase demodulation circuit, and outputs the demodulated data to the positioning calculation unit 4 as data having the data frame configuration as described above.
[0023]
As shown in FIG. 1, the positioning calculation unit 4 inputs / outputs data to / from the CPU 12, a ROM 13 in which a predetermined program is stored, a RAM (range data storage means) 14 for storing / reading data, and the RAM 14. And a data input / output device 15 to be configured. Here, the RAM 14 is provided with a trajectory parameter holding unit for holding a trajectory parameter in order to start positioning at an early timing after startup, as in the normal case, and further, range data for storing range data. A storage unit is provided.
Then, the CPU 12 executes predetermined processing based on the program stored in the ROM 13, whereby the positioning calculation unit 4 performs positioning calculation and outputs position data.
[0024]
FIG. 4 is a flowchart showing the flow of processing when the power is turned on in the GPS receiver as described above.
First, when the power is turned on to activate the GPS receiver (step S101), a signal transmitted from a GPS satellite is received by the GPS antenna unit 1 of the GPS receiver after a propagation time corresponding to the distance. The The signal received by the GPS antenna unit 1 is down-converted to a predetermined intermediate frequency by the intermediate frequency converter 2 and enters the demodulation unit 3.
Thereafter, the demodulator 3 receives signals from each of a plurality of GPS satellites that can be captured at that time, and assigns a channel to each GPS satellite (step S102).
[0025]
Then, in each channel, data demodulation from the assigned GPS satellites is started (step S103), and when the signal is despread by the spectrum despreader 10, a pseudo random noise chip included in the signal is obtained. It counts (measures) every predetermined time, for example, every 100 [msec], and outputs the count value to the positioning calculation unit 4 as range data. Then, the range data output to the positioning calculation unit 4 is stored in the range data storage unit of the RAM 14 via the data input / output device 15 (step S104).
[0026]
On the other hand, in each channel, when the first to third subframes are obtained in each main frame of the obtained data in the positioning calculation unit 4, the trajectory parameters stored here are extracted (step S105). .
After capturing the trajectory parameters in all channels (step S106), positioning calculation is performed based on the obtained trajectory parameters and the range data output from the spectrum despreader 10 (step S107), and the position data Is output (step S108). At this time, in these steps S107 to S108, the current position data and the past position data at the time before the time when the trajectory parameter acquisition is completed are output as follows.
[0027]
First, after completing the acquisition of orbital parameters, in order to obtain current position data at that time, as in the past, based on the orbital parameters and range data acquired at that time, simultaneous data from at least four GPS satellites Solve the equation.
That is, the position of the GPS satellite (x _s , Y _s , Z _s ) And GPS receiver position (x _u , Y _u , Z _u ) And the arrival delay time of signals from GPS satellites,
[(X _s -X _u ) ² + (Y _s -Y _u ) ² + (Z _s -Z _u ) ² ] ^1/2 = C · (t _u -T _s )
The relationship holds. Where t _s Is the time when the signal was transmitted by the GPS satellite (= range data), t _u Is the time received by the GPS receiver, and c is the speed of light. And the unknown is (x _u , Y _u , Z _u ) And t _u Then, the current position data can be obtained by solving the following simultaneous quaternary quadratic equation with four GPS satellites.
[(X ₁ -X _u ) ² + (Y ₁ -Y _u ) ² + (Z ₁ -Z _u ) ² ] ^1/2 = C · (t _u -T ₁ )
[(X ₂ -X _u ) ² + (Y ₂ -Y _u ) ² + (Z ₂ -Z _u ) ² ] ^1/2 = C · (t _u -T ₂ )
[(X _Three -X _u ) ² + (Y _Three -Y _u ) ² + (Z _Three -Z _u ) ² ] ^1/2 = C · (t _u -T _Three )
[(X _Four -X _u ) ² + (Y _Four -Y _u ) ² + (Z _Four -Z _u ) ² ] ^1/2 = C · (t _u -T _Four )
[0028]
Then, after completing the acquisition of the orbital parameter, after the GPS receiver is turned on (started) until the acquisition of the orbital parameter is completed, that is, to obtain past position data, the acquired current orbital parameter is obtained. Is used to obtain position data corresponding to each of the past range data stored in the range data storage unit of the RAM 14. Here, since the orbital parameter includes a parameter of a function formula that indicates a movement locus of the GPS satellite and uses time as a variable, past position data is obtained from the function formula and the stored range data. It can be obtained by approximation. The function equation indicating the movement trajectory of the GPS satellite is updated in, for example, about 2 hours. Therefore, after the GPS receiver is activated, the orbital parameter is captured within about 30 seconds. Approximate data can be used sufficiently for the obtained range data (stored range data).
Thus, if the acquisition of the orbital parameter is completed, the position data at the time before the acquisition of the orbital parameter is completed after the GPS receiver is started can be obtained. Here, in FIG. 7, “range data measurement” in the figure indicates the range data count (measurement) timing in the demodulator 3. In the present embodiment, the range data stored in the range data storage unit of the RAM 14 after the time point (b) of spectrum despreading and data demodulation (see symbol (Y) in FIG. 7) is performed on all the satellites that can be captured. Start memorizing. Then, after the acquisition of orbital parameters is completed (after the symbol (X) in FIG. 7), the time point before that (the measurement timing of the range data between the symbols (Y)-(X) in FIG. 7) Position data can be obtained.
[0029]
The program as described above may be preinstalled in the GPS receiver, but may be stored in various storage media such as a CD-ROM and a DVD in a state readable by the GPS receiver. .
[0030]
The GPS receiver can be applied to, for example, a navigation system. In other words, after starting the navigation system (GPS receiver) in step S108, the previous position data can be obtained after the time when the trajectory parameters are captured. Some conventional navigation systems have a function of accumulating current position data after generating trajectory parameters and starting positioning, and generating a movement locus based on these data. In addition to this, in this navigation system, the positioning calculation unit (movement route generation means) 4 uses the movement locus (movement route information) of the GPS receiver before the orbit parameters are captured based on the stored range data. ) Can be generated. For this reason, even if the GPS receiver is started and moved at the same time, it is possible to form a movement trajectory soon after the power is turned on.
[0031]
The GPS receiver as described above can also be applied to various portable terminals such as a digital camera. FIG. 5 is a block diagram showing a schematic configuration of a digital camera (GPS receiver) having a GPS function.
As shown in this figure, the digital camera 20 includes a GPS block 21 and a photographing block 22. Here, the GPS block 21 includes the GPS antenna unit 1, the intermediate frequency converter 2, the demodulation unit 3, the positioning calculation unit 4, and the clock unit 5 described above. The photographing block 22 includes an imaging unit 23, an operation unit 24 for operating the imaging unit 23, an image processing unit 25, and a display unit 26 such as a monitor. Here, the image processing unit 25 includes a CPU 27, a ROM 28 storing a predetermined program, a RAM 29 for storing / reading data, and a data input / output device 30 for inputting / outputting data to / from the RAM 29. ing. The RAM 29 stores an image data storage unit that stores image data captured by the imaging unit 23, a time data storage unit that stores time data when a predetermined operation is performed in the operation unit 24, and positioning in the GPS block 21. A position data storage unit for storing the position data.
[0032]
In the digital camera 20, when a predetermined operation (for example, a shooting operation) is performed by the operation unit 24, image data captured by the image capturing unit 23 is stored in the image data storage unit of the RAM 29, and together with this, the operation unit The 24 operation times, that is, the shooting time data is stored in the time data storage section of the RAM 29. Further, when a predetermined operation (for example, photographing operation) is performed with the operation unit 24, the GPS block 21 measures the position data at that time and stores it in the position data storage unit of the RAM 29. When the captured image data is displayed on the display unit 26, the image data and time data and position data corresponding to the image data are extracted from the RAM 29, and these are displayed as a unitary image file. Time data and position data can be displayed as information.
[0033]
Here, in the case of a conventional digital camera, after waiting for about 30 seconds after starting, the position data could not be included in the image data until positioning was possible. After activation, the previous position data can be obtained after the time when the trajectory parameters are captured. For this purpose, when a photographing operation is performed with the operation unit 24 after the terminal is started and before the trajectory parameters are captured, the range data at that time is stored in the range data storage unit of the RAM 14. Since the orbital parameter is captured, position data before the orbital parameter is captured can be obtained in step S108 of the positioning program in the GPS block 21 (see FIG. 4). The position data may be stored in the position data storage section of the RAM 29.
In this way, even for an image shot immediately after starting the digital camera, it is possible to acquire and incorporate position data at the time of shooting if the trajectory parameters are obtained.
[0034]
In the above embodiment, only the example in which the position data obtained by the GPS receiver is applied to a navigation system, a digital camera, etc. has been shown, but the position data obtained by the GPS receiver is also used in other devices. In this case, the same effect can be obtained by applying the present invention in the same manner as described above.
Further, the method of using the obtained position data is not limited to the generation of the movement trajectory in the navigation system and the generation of the shooting position information in the digital camera shown in the above embodiment, and other methods may be used.
Furthermore, in the above-described embodiment, for example, a configuration in which trajectory data is stored and positioning is performed at an early timing by using the trajectory data at the time of restart is not particularly described. It goes without saying that the present invention becomes more effective when combined with the above.
In addition, storage means such as a CD-ROM, DVD, memory, and hard disk for storing the program as described above, and the program is read from the storage means and directly or indirectly to the device executing the program. It may be in the form of a transmission device or the like provided with a transmission means for transmitting.
[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain the previous position data after the GPS receiver is powered on and after the trajectory parameters are captured. Therefore, for example, in a navigation system, it is possible to obtain a movement locus from an earlier timing than before, and in a terminal such as a digital camera, position data can be included in an image taken immediately after startup. It becomes possible and the usability improves.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of a GPS receiver in the present embodiment.
FIG. 2 is an explanatory diagram showing a flow of signal reception and demodulation in a GPS receiver.
FIG. 3 is a frame configuration of a signal transmitted from a GPS satellite.
FIG. 4 is a flowchart showing a flow of processing when power is turned on in the GPS receiver.
FIG. 5 illustrates an example of a GPS receiver according to the present embodiment, and is an explanatory diagram illustrating a schematic configuration of a digital camera having a GPS function.
FIG. 6 is an explanatory diagram showing a schematic configuration of a commonly used GPS system.
FIG. 7 shows a GPS positioning operation performed by a GPS receiver.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... GPS antenna part (signal receiving means, signal receiving part), 3 ... Demodulation part (range data acquisition means), 4 ... Positioning calculation part (Orbit parameter acquisition means, position data calculation means, movement path generation means, position data generation) 10) Spectrum despreader, 11 ... Data demodulator, 12 ... CPU, 14 ... RAM (range data storage means), 20 ... Digital camera (GPS receiver), 23 ... Imaging unit, 24 ... Operation unit, 25. Image processing unit

Claims (5)

In a GPS receiver that performs positioning based on signals transmitted from a plurality of GPS satellites,
Signal receiving means for receiving the signal from the GPS satellite;
Range data acquisition means for acquiring range data from the signal received by the signal reception means;
Trajectory parameter capturing means for capturing trajectory parameters from the signal received by the signal receiving means;
Range data storage means for storing the range data acquired by the range data acquisition means before the trajectory parameters are acquired by the trajectory parameter acquisition means;
Position data calculating means for calculating position data corresponding to the range data stored in the range data storage means based on the trajectory parameters captured by the trajectory parameter capturing means;
A GPS receiver comprising:   And a movement path generation unit that generates movement path information of the GPS receiver before the trajectory parameter is captured by the trajectory parameter capturing unit based on the position data calculated by the position data calculation unit. The GPS receiver according to claim 1.   2. The position data calculating unit calculates position data when a predetermined operation is performed with the GPS receiver before the orbit parameter is captured by the orbit parameter capturing unit. GPS receiver. Receive signals from multiple GPS satellites,
Storing the range data captured from the time when the range data included in the received signal is captured until the time when the trajectory parameter included in the signal is captured ;
Characterized in that after the time when the trajectory parameters are adapted to be captured, and positioning calculation on the basis of said range data which has been stored with the trajectory parameters, we obtain the previous position data in which the trajectory parameters are captured GPS positioning method. In a storage medium that stores a program to be executed by a computer so that the computer can read the program,
The program is
Processing to store the range data acquired from the time when acquisition of range data from signals from a plurality of GPS satellites is started until the time when orbital parameters included in the signal are captured ;
Subsequent to capture the trajectory parameters, a process of the basis of the trajectory parameters, generates position data indicating the position at the time corresponding to the range data that has been said memory,
That the computer executes.

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