JPH0875838A - Gps receiving device - Google Patents

Abstract

PURPOSE: To enhance position measuring accuracy by correcting the error of altitude information on a map. CONSTITUTION: Data of navigation message and phase of pseudonoise code synchronized with the message are demodulated with a signal receiving demodulator from a receiving signal of electric wave from at least three GPS satellites and outputted to a position measuring operation part 13. The position of the GPS satellite is calculated there, and the distance to the signal receiving position is calculated from the phase of the pseudonoise code. The signal receiving position is calculated with altitude information Db on a map. Signal receiving position data Da of latitude, longitude, and altitude obtained by coordinate transformation of the signal receiving position are outputted. Altitude error information Dd obtained by calculating the error of the altitude information Db on the map by using altitude information Dc obtained by position measuring calculation of the last time by a altitude error calculation part 14 is multiplied by a value less than l-The value obtained is added to the error of the altitude information Db on the map, and the data obtained is outputted to the position measuring operation part 13 as altitude information De. By repeating these processes, the error (offset value) of the altitude information Db on the map is gradually corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver for use in a vehicle navigation device or the like, which corrects an error in altitude information of a map and performs positioning calculation.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing the structure of a conventional GPS receiver. In FIG. 3, this example shows an antenna 1 that receives radio waves from three or more GPS satellites in the sky.
And a reception demodulation unit 2 that performs frequency conversion of the reception signal from the antenna 1 and outputs the navigation message data for each GPS satellite and the demodulation data of the phase of the synchronized pseudo noise code, and the reception demodulation unit. A positioning calculation unit 3 for calculating the current reception position (two-dimensional or three-dimensional information) from the demodulated data from 2 is provided.

The operation of the GPS receiver constructed as above will be described below.

Received signals of radio waves from three or more GPS satellites received by the antenna 1 are input to the reception demodulator 2.
The reception / demodulation unit 2 outputs the navigation message data for each GPS satellite and the phase data of the synchronized pseudo noise code to the positioning calculation unit 3. The positioning calculation unit 3 calculates the position of each GPS satellite from the data of the navigation message, and also calculates the distance between each GPS satellite and the reception position from the data of the phase of the synchronized pseudo noise code. By using the positions of these GPS satellites and the distance between the GPS satellites and the altitude information of the map from a CD-ROM or the like (not shown), the simultaneous system is solved and the reception position is calculated.
This reception position is subjected to coordinate conversion to output the reception position data of latitude, longitude and altitude.

As described above, in the above-mentioned conventional GPS receiver, if radio waves from three or more GPS satellites can be received,
By using the altitude information of the map, it is possible to obtain the three-dimensional (latitude, longitude and altitude) reception position.

[0006]

However, in the GPS receiver of the conventional example, since the positioning calculation (calculation of the reception position) is performed using the altitude information of the map having an error, the error of the altitude information of this map is This is a positioning error, and there is a drawback that the altitude error becomes large especially in a place where the altitude changes greatly.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide an excellent GPS receiver capable of correcting an error in altitude information of a map and improving its positioning accuracy.

[0008]

In order to achieve the above object, the GPS receiving apparatus according to claim 1 outputs a navigation message for each GPS satellite and a phase data of a synchronized pseudo noise code. An error between the altitude calculated by the positioning calculation by the positioning calculation unit and the positioning calculation unit for obtaining the coordinate data of the reception position from the data from the GPS reception demodulation unit and the input altitude information. And an altitude error calculation / correction means for transmitting the altitude information corrected by this error to the positioning calculation means as altitude information of the positioning point.

The GPS receiver according to claim 2 is a GPS receiver.
GPS receiving and demodulating means for outputting a navigation message for each satellite and phase data of synchronized pseudo noise code;
Positioning calculation means for obtaining data from the reception demodulation means and coordinate data of the reception position from the altitude information, and altitude for calculating and transmitting an error between the altitude calculated by the positioning calculation means and the altitude information of the positioning point The error calculation means and the altitude information corrected by the error calculated by the altitude error calculation means based on the altitude difference between the lowest altitude and the highest altitude within the range for calculating the altitude error are sent to the positioning calculation means as altitude information of the positioning point. And an altitude error correction means for performing the adjustment.

[0010]

With this structure, the GPS according to claim 1
The receiving device calculates an error between the altitude calculated by the positioning calculation and the altitude information of the positioning point. The altitude information corrected by this error is sent to the positioning calculation means as altitude information of the positioning point.
The next positioning calculation is performed using the corrected altitude information.
Therefore, the error of the altitude information on the map is corrected, and the positioning accuracy is improved.

The GPS receiver according to the second aspect calculates an error between the altitude calculated by the positioning calculation and the altitude information of the positioning point. The altitude information in which the error is corrected based on the altitude difference between the minimum altitude and the maximum altitude in the range where the altitude error is calculated is sent as the altitude information of the positioning point, and the next positioning calculation is performed. Thereby, the error of the altitude information of the map is corrected together with the altitude difference between the minimum altitude and the maximum altitude in the surrounding range, and the positioning accuracy is further improved.

[0012]

Embodiments of the GPS receiving apparatus of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a GPS receiver according to the first embodiment of the present invention. In FIG. 1, in this example, an antenna 11 that receives radio waves from three or more GPS satellites in the sky, frequency conversion is performed on a reception signal from the antenna 11, and a navigation message of each GPS satellite is further transmitted. A reception demodulation unit 12 that outputs demodulation data of the phase of the pseudo noise code synchronized with the data is provided. Furthermore, the current position of reception is calculated from the demodulated data from the reception demodulation unit 12, and the position calculation unit 13 that outputs the reception position data Da of the three-dimensional information (latitude, longitude, and altitude) of the current position, and the previous position calculation. An altitude error calculation unit 14 that calculates an altitude difference between the altitude information Db of the map used and the altitude information Dc from the positioning operation unit 13 calculated in the previous positioning calculation is provided. Further, the altitude error correction unit 15 that receives the altitude error information Dd and the altitude information Db calculated by the altitude error calculation unit 14 and outputs the altitude information De corrected for the offset value error in the error of the map altitude information Db. Is provided.

Next, the operation of the first embodiment will be described. Received signals of radio waves from three or more GPS satellites received by the antenna 11 are input to the reception demodulation unit 12. The reception demodulation unit 12 outputs the navigation message data for each GPS satellite and the phase data of the synchronized pseudo noise code to the positioning calculation unit 13. Here, in the first positioning, the altitude information correction unit 15 outputs the altitude information Db of the map from a CD-ROM or the like (not shown) as it is to the positioning operation unit 13 as the altitude information De. The positioning calculation unit 13 calculates the position of each GPS satellite from the data of the navigation message from the reception demodulation unit 12, and the data of the phase of the synchronized pseudo noise code between the GPS satellite and the reception position. To calculate the distance. By using the positions of these GPS satellites and the distance between the GPS satellites and the altitude information Db of the map from a CD-ROM or the like, the simultaneous system is solved and the reception position is calculated. Convert the coordinates of this receiving position,
The reception position data Da of latitude, longitude and altitude is output.
In the second positioning calculation after the first positioning calculation, the altitude error calculation unit 14 uses the altitude information Dc calculated in the previous positioning calculation to calculate the error included in the map altitude information Db. In this error calculation, the altitude difference between the altitude information Db of the map used in the previous positioning calculation and the altitude information Dc from the positioning calculation unit 13 calculated in the previous positioning calculation is calculated.
In this case, since the altitude of the altitude information Dc also has an error, it is more accurate to use the difference between the value obtained by arithmetically averaging the altitude calculated by the positioning calculation (altitude information Dc) and the altitude of the altitude information Db of the map. Positioning calculation becomes possible. Next, the altitude information correction unit 15 multiplies the altitude error information Dd calculated by the altitude error calculation unit 14 by a value smaller than “1” and adds this value to the error of the altitude information Db on the map to perform positioning calculation. The altitude information De is output to the unit 13. By repeating this process, the error of the offset value in the error of the altitude information Db of the map is gradually corrected.

As described above, in the first embodiment, the altitude information Db of the map is corrected using the altitude information calculated by the three-dimensional positioning calculation. Positioning calculation is performed based on the corrected accurate map altitude information Db, and the positioning accuracy is improved.

FIG. 2 is a block diagram showing the configuration of the second embodiment. In FIG. 2, this second embodiment has the same configuration as the first embodiment shown in FIG. That is, the antenna 1
1, a reception demodulation unit 12, a positioning calculation unit 13, an altitude error calculation unit 14, and an altitude information correction unit 15. In the second embodiment, the altitude information correction unit 15 is supplied with the altitude information Db of the map, and the area (altitude information D of the map D
The area minimum and maximum altitude information Df indicating the minimum and maximum altitudes in b) is input.

Next, the operation of the second embodiment will be described. Here, except for the operation of the altitude information correction unit 15, it is the same as the first embodiment shown in FIG. In the second embodiment, the error of the altitude information Db of the map increases in proportion to the altitude difference between the lowest altitude in the area and the highest altitude in the area in the lowest and highest altitude information Df in the area. The altitude difference between the lowest altitude in the area and the highest altitude in the area is multiplied by the altitude error information Dd calculated by the altitude error calculation unit 14 and output to the positioning calculation unit 13 as altitude information De. By repeating this process, the error (offset value) of the altitude information Db of the map when the ratio of the minimum altitude in the area and the maximum altitude in the area in the altitude information Db of the map is large is corrected with higher accuracy.

As described above, in the second embodiment, the altitude information Db of the map is corrected as in the first embodiment. When this correction is performed, the error of the altitude information Db of the map when the ratio of the minimum altitude in the area and the maximum altitude in the area is large is corrected with higher accuracy.

[0019]

As is apparent from the above description, according to the GPS receiving apparatus of the first aspect, the error between the altitude calculated by the positioning calculation and the altitude information of the positioning point is calculated and corrected by this error. The altitude information is sent to the positioning calculation means as altitude information of the positioning point. Since the next positioning calculation is performed using this corrected altitude information, the error in the altitude information of the map is corrected, and the positioning accuracy is improved.

According to the GPS receiver of claim 2,
The error between the altitude calculated by the positioning calculation and the altitude information of the positioning point is calculated. The next positioning calculation is performed by sending the altitude information in which the error is corrected based on the difference in altitude between the lowest altitude and the highest altitude in the range where the altitude error is calculated, as the altitude information of the positioning point. As a result, the error of the altitude information of the map can be corrected together with the altitude difference between the lowest altitude and the highest altitude in the surrounding area, and the positioning accuracy can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a GPS receiving apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment.

FIG. 3 is a block diagram showing the configuration of a conventional GPS receiver.

[Explanation of symbols]

 12 reception demodulation unit 13 positioning calculation unit 14 altitude error calculation unit 15 altitude information correction unit

Claims (2)

[Claims] 1. A GPS reception / demodulation means for outputting a navigation message for each GPS satellite and phase data of a synchronized pseudo noise code, data from the GPS reception / demodulation means, and a reception position from input altitude information. Positioning calculation means for obtaining coordinate data, and an error between the altitude calculated by the positioning calculation by the positioning calculation means and the altitude information of the positioning point,
A GPS receiving device, comprising: altitude error calculation and correction means for sending the altitude information corrected by this error to the positioning calculation means as altitude information of a positioning point. 2. A GPS receiving and demodulating means for outputting a navigation message for each GPS satellite and phase data of a synchronized pseudo noise code, and data from the GPS receiving and demodulating means and coordinate data of a receiving position from altitude information are obtained. Positioning calculation means, altitude error calculation means for calculating and transmitting an error between the altitude calculated by the positioning calculation means and the altitude information of the positioning point, and the minimum and maximum altitudes in the range for calculating the altitude error. GPS reception, comprising altitude error correction means for sending to the positioning calculation means altitude information corrected by an error calculated by the altitude error calculation means based on an altitude difference from the altitude to the positioning operation means. apparatus.