JP2000292519A - Dgps receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the setting speed of a reference beacon station from which correction data are to be obtained. SOLUTION: A beacon station instructing section 30 which selects a reference beacon station from which correction data Da(n) are to be received and instructs a beacon receiving section 26 to receive the data Da(n) from the selected station is provided with a distance discriminating section 34 which discriminates whether or not the base station is positioned within a prescribed range from a DGPS receiver 14. A distance calculating section 36 only finds the distance between the base beacon station which is discriminated to be positioned within the prescribed range from the receiver 14 by means of the discriminating section 34 and the receiver 14 and a beacon station selecting section 38 and a beacon station setting section 40 are constituted to select the base beacon station from which the correction data Da(n) are to be received based on the distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a DGPS receiver, and more particularly, to a DG capable of speeding up a process of setting a beacon reference station for obtaining correction data.
It relates to a PS receiver.

[0002]

2. Description of the Related Art GPS (Global Positioning System)
Is a satellite navigation system operated by the United States, with standard positioning services open to private use. This GPS
Is composed of a plurality of GPS satellites and a GPS receiver for measuring its own position. The GPS receiver is
Receiving GPS signals contained in radio waves from GPS satellites,
The position of the vehicle is obtained by measuring the distance between the vehicle and a GPS satellite based on the GPS signal.

[0003] DGPS (Differential Global Position)
ing System) is a system in which the position detection accuracy is improved with respect to the GPS, and the GPS constituting the GPS
It comprises a group of satellites, a beacon reference station installed at a known position, and a DGPS receiver.

[0004] The beacon reference station transmits a GP from a GPS satellite.
Receiving the S signal, calculating its own position based on the GPS signal, and calculating a calculation error included in the calculated position from the calculated position and the known own position. It is configured to transmit correction data based on the error.

The DGPS receiver has a GPS receiver and a beacon receiver, and corrects its own position by correcting the position obtained by the GPS receiver based on the correction data received by the beacon receiver. Is configured to be measured with high accuracy.

[0006] Beacon reference stations are installed at a plurality of locations on the ground, and radio waves of different frequencies respectively
Correction data with different baud rates are being transmitted. Therefore, the beacon receiving unit of the DGPS receiver selects a beacon reference station from which the correction data is to be received (for example, the closest beacon reference station) from the group of beacon reference stations, and receives the beacon reference station in accordance with the selected beacon reference station. It is configured to set a frequency and a baud rate.

In order to set such a reception frequency and a baud rate, the DGPS receiver is provided with a database in which the positions of beacon reference stations, station ID numbers, frequencies, baud rates, and the like are recorded as data around the world. By searching the database based on the positions obtained by the GPS receiving unit and the beacon receiving unit, the frequency, the baud rate, and the like are set in accordance with a desired beacon reference station.

Specifically, for all the beacon reference stations stored in the database, the distance between the beacon reference station and the DGPS receiver is obtained, and based on the obtained distance, the distance from the DGPS receiver closest to the DGPS receiver is determined. Is selected, and the receiving frequency and the baud rate of the beacon receiving unit are set in accordance with the beacon reference station.

[0009]

However, in the above-described DGPS receiver, when selecting a beacon reference station from which correction data is to be received, all the beacon reference stations stored in the database are assigned to the beacon reference station. It is necessary to calculate the distance between the reference station and the DGPS receiver and to compare the calculated distances. Therefore, there has been an inconvenience that it takes a lot of time to select a beacon reference station.

[0010] The present invention has been made in view of such a problem, and a DGP capable of speeding up a process of setting a beacon reference station from which correction data is to be obtained.
It is intended to provide an S receiver.

[0011]

According to the present invention, the instructing means for instructing the beacon reference station to receive the correction data to the beacon receiving means includes the position of the beacon reference station from the database and the DGPS from the positioning calculating means. Based on the location of the receiver, the beacon reference station
It has a determination means for determining whether or not it is located within a predetermined range from the PS receiver. In the distance calculation means, for the beacon reference station determined to be located within a predetermined range from the DGPS receiver by the determination means,
The distance between the beacon reference station and the DGPS receiver is determined (the invention according to claim 1).

With this configuration, it is possible to speed up the process of setting a beacon reference station from which correction data is to be obtained.

[0013] In this case, the determination means may include a first determination criterion as to whether the longitude of the position of the beacon reference station is within a predetermined range with respect to the longitude of the position of the DGPS receiver, and / or The beacon reference station is located within a predetermined range from the DGPS receiver based on a second criterion for determining whether the latitude of the position of the reference station is within a predetermined range with respect to the latitude of the position of the DGPS receiver. It is determined whether or not (the invention according to claim 2).

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a DGPS (Differential Global Positioning System) to which an embodiment of the present invention is applied.
em) 10 is schematically shown.

In the DGPS 10, a plurality of beacon reference stations 12 (n) #n installed at known positions are station ID numbers. In FIG. 1, two beacon reference stations 12 (n = a and n = b) are provided. Only (n) is shown.船舶 and ship S
DGPS receiver 14 mounted on the
And a plurality of GPS satellites (GPS satellite group) 16 constituting a positioning system.

FIG. 2 shows the configuration of the DGPS receiver 14.

As shown in FIG. 1 and FIG. 2, a DGPS receiver 14 is a GPS receiver (GPS receiving means) for receiving a GPS signal Sg contained in a radio wave transmitted from a GPS satellite 16 via a GPS antenna 20. ) 22 and a beacon receiving section (beacon receiving means) 26 for receiving, via a beacon antenna 24, correction data Da (n) contained in a radio wave transmitted from the beacon reference station 12 (n).

The DGPS receiver 14 (ie, the ship S) receives the GPS signal Sg from the GPS receiver 22 and the correction data Da (n) from the beacon receiver 26 based on the GPS signal Sg. Has a positioning calculation unit (positioning calculation means) 28 for obtaining the position Pa. This positioning calculation unit 28 is, specifically, a GP from the GPS reception unit 22.
Based on the S signal Sg, the DGPS receiver 14 and the GP
By calculating the distance from the S satellite 16, the DG
The pseudo position of the PS receiver 14 is obtained, and the pseudo position is corrected based on the correction data Da (n) from the beacon receiving unit 26 to obtain the DGP.
It is configured to obtain the position Pa of the S receiver 14.
Then, from the positioning calculation unit 28, the obtained position Pa of the DGPS receiver 14 is output as position data Dp to a beacon station instruction unit 30 and a display device (not shown) to be described later.

Further, the DGPS receiver 14 selects a beacon reference station 12 (n) to receive the correction data Da (n), and receives the correction data Da (n) from the selected beacon reference station 12 (n). A beacon station instructing unit (instructing means) 30 for instructing the beacon receiving unit 26 to set a receiving frequency or the like so as to be able to perform the operation.

The beacon station instructing section 30 stores the database 3
2. Distance calculation determination unit (determination means) 34, distance calculation unit (distance calculation means) 36, beacon station selection unit (selection / setting means) 38, and beacon station setting unit (selection / setting means) 4
0.

In the database 32, the position Pb (n), the station ID number n, the frequency, the baud rate, etc. of the beacon reference station 12 (n) all over the world. ｝ Is stored as data. Then, from the database 32, the position Pb (n) of the beacon reference station 12 (n) is provided for each beacon reference station 12 (n) in accordance with a data request signal Sd from control means or the like or a beacon station selection unit 38 (not shown). Are read out, for example, in the order of station ID number n, and the beacon station data D
It is output to the distance calculation determination unit 34 as b (n).

The distance calculation determination unit 34 is a DGPS receiver 14 supplied as position data Dp from the positioning calculation unit 28.
Based on the position Pa of the beacon reference station 12 included in the beacon station data Db (n) from the database 32.
It is determined whether or not the position Pb (n) of (n) is within a predetermined range from the position Pa of the DGPS receiver 14.

Specifically, first, the position Pa of the DGPS receiver 14 is specified using the longitude Xa and the latitude Ya, and the beacon reference station 12 (n) (in the example shown in FIG.
= A) is specified using longitude Xb and latitude Yb. Whether the longitude Xb of the beacon reference station 12 (n) is within a predetermined range (for example, a range of Xa ± θx) with respect to the longitude Xa of the DGPS receiver 14 (first determination criterion), 12 (n)
Is determined to be within a predetermined range (for example, a range of Ya ± θy) with respect to the latitude Ya of the DGPS receiver 14 (second determination criterion).

Note that θx and θy are predetermined values representing angles, and the values are obtained by the following equations (1) and (2).

Θx = 400 km / {(60 × 1.852) km × cos (Ya)} (1) θy = 400 km / (60 × 1.852) km (2) And in the formula (2), the value [4
00 km] is a predetermined range for the longitude Xa (the same applies to the predetermined range for the latitude Ya).
Is the distance on the earth's surface. That is, this value can be set arbitrarily.

Also, a numerical value [(60 × 1.852) km]
Is the distance on the earth's surface per degree latitude. In addition,
In the expression (1), [cos (Ya)] represents a correction corresponding to a change in the distance on the earth's surface per 1 ° of longitude depending on the latitude.

If the longitude Xb and the latitude Yb are both within Xa ± θx and Ya ± θy, respectively, and satisfy the first and second criteria, the beacon reference station 12 (n) It is determined that the position Pb (n) is within a predetermined range from the position Pa of the DGPS receiver 14, and in other cases (at least one of the longitude Xb or the latitude Yb is within the range of Xa ± θx or Ya ± θy). Without satisfying the first or second criterion),
The position Pb (n) of the beacon reference station 12 (n) is DGPS
It is determined that the position is not within a predetermined range from the position Pa of the receiver 14.

When either the longitude Xb or the latitude Yb is within the range of Xa ± θx or Ya ± θy (when either one of the first and second criteria is satisfied), the beacon Position Pb of reference station 12 (n)
(N) may be determined to be within a predetermined range from the position Pa of the DGPS receiver 14.

The distance calculation judging section 34 is a beacon reference station 1
If it is determined that 2 (n) is within a predetermined range from the DGPS receiver 14, the beacon station data Db (n) is supplied to the distance calculation unit 36 together with the position data Dp, while the beacon reference station 12 When it is determined that (n) is not within the predetermined range from the DGPS receiver 14, the cancel signal Sc is output to the beacon station selecting unit 38.

The distance calculation section 36 receives the beacon station data Db (n) and the position data Dp from the distance calculation determination section 34.
From the DGPS receiver 14 to the beacon reference station 1
2 (n) (n = a in the example shown in FIG. 1)
(N) is obtained, and this distance L (n) is calculated as distance data Dx
As (n), the data is supplied to the beacon station selector 38 together with the beacon station data Db (n).

The beacon station selecting section 38 includes a distance calculating section 36
The three beacon reference stations 12 (n) closest to the DGPS receiver 14 are selected based on the distance data Dx (n) from.

Specifically, the beacon station selecting unit 38
From the cycle # database 32, the first station ID number n
Is output from the beacon station data Db (n) corresponding to the last beacon station data Db (n) corresponding to the last station ID number n.
During cycle｝ until b (n) is output,
The distances L (n) included in the distance data Dx (n) supplied so far are compared with each other, and the distance data Dx (n) corresponding to the three smallest distances L (n) among these are compared.
And beacon station data Db (n) are always stored.

For example, when new distance data Dx (n) is supplied, the distance L (n) included in the distance data Dx (n) and the three stored distance data D
Comparison with distance L (n) included in x (n) is performed, and distance data Dx (n) and beacon station data Db (n) corresponding to the three minimum distances L (n) at this time are stored. I do.

The beacon station selecting section 38 outputs the distance data Dx corresponding to one beacon reference station 12 (n).
When the comparison processing of the distance L (n) accompanying the supply of (n) is completed, the next station ID number n (n
= N + 1) to supply the data request signal Sd for requesting the beacon station data Db (n) corresponding to the beacon reference station 12 (n). The beacon station selecting unit 38 also sends the data request signal S to the database 32 when the cancel signal Sc is supplied from the distance calculation determining unit 34.
Supply d.

The last beacon station data Db (n) output from the database 32, that is, the beacon station data Db (n) corresponding to the last station ID number n includes the beacon station data Db (n). The information (end information) indicating the last output from the database 32 is included, and the beacon station selection unit 38 ends the selection of the beacon reference station 12 (n) with the supply of the end information. The beacon station data Db (n) and the distance data Dx (n) for the three selected beacon reference stations 12 (n) are selected at this time.
To the beacon station setting unit 40.

The beacon station setting section 40 selects the nearest beacon reference station 12 (n) based on the three distance data Dx (n) included in the selected beacon station data Dc from the beacon station selection section 38. , The information {i.e., the beacon station data Db (n) and the distance data Dx (n)} of the selected beacon reference station 12 (n) are supplied to the beacon receiving unit 26 as the determined beacon station data Dd.

In this case, the beacon receiving section 26 corrects the correction data Da (n) from the beacon reference station 12 (n) set by the beacon station setting section 40 based on the determined beacon station data Dd from the beacon station setting section 40. ) To receive the beacon reference station 12 (n).
Make settings such as baud rate.

As described above, according to the present invention, the beacon reference station 12 (n) to receive the correction data Da (n)
Is selected, first, in the distance calculation determination unit 34,
The position Pb (n) of the beacon reference station 12 (n) is DGPS
It is determined whether the position is within a predetermined range from the position Pa of the receiver 14. And beacon reference station 1
Only when the position Pb (n) of 2 (n) is within a predetermined range from the position Pa of the DGPS receiver 14, the distance calculation unit 3
At 6, the DGPS receiver 14 sends the beacon reference station 1
Processing for obtaining a distance L (n) to 2 (n) is performed.

Therefore, the position Pb is stored in the database 32.
Beacon reference station 12 in which data such as (n) is stored
(N) from the beacon reference station 12 (n) to the DGP
The calculation of the distance L (n) to the S receiver 14 can be limited, so that the processing for setting the beacon reference station 12 (n) can be speeded up.

[0041]

In the DGPS receiver according to the present invention, when setting a beacon reference station for obtaining correction data, it is determined whether or not the beacon reference station is located within a predetermined range from the DGPS receiver. Thus, the number of beacon reference stations for calculating the distance to the DGPS receiver is limited. Therefore, it is possible to speed up the process of setting the beacon reference station.

[Brief description of the drawings]

FIG. 1 is a DGPS to which an embodiment of the present invention is applied.
FIG. 3 is an explanatory diagram schematically showing the configuration of FIG.

FIG. 2 is a block diagram illustrating a configuration of a DGPS receiver included in the DGPS of FIG. 1;

[Explanation of symbols]

14 DGPS Receiver 22 GPS Receiver (GPS Receiver) 26 Beacon Receiver (Beacon Receiver) 28 Positioning Calculator (Positioning Calculator) 30 Beacon Station Instructor (Instructor) 32 Database 34 Distance calculation judging section (judging means) 36 ... Distance calculating section (distance calculating means) 38 ... Beacon station selecting section (selecting / setting means) 40 ... Beacon station setting section (selecting / setting means)

Claims (2)

[Claims] A GPS receiving means for receiving a GPS signal from a GPS satellite group; a beacon receiving means for receiving correction data from a beacon reference station; a GPS signal from the GPS receiving means; DGPS reception comprising: positioning calculation means for obtaining the own position based on the correction data from the beacon reception means; and instruction means for instructing the beacon reception means of a beacon reference station to receive the correction data. In the apparatus, the indicating means, a database storing data including a plurality of positions of the beacon reference station, a position of the beacon reference station from the database,
Determining means for determining whether the beacon reference station is located within a predetermined range from the DGPS receiver based on the position of the DGPS receiver from the positioning calculation means; Distance calculation means for determining the distance between the beacon reference station and the DGPS receiver for the beacon reference station determined to be located within a predetermined range from the device, based on the distance obtained by the distance calculation means, Said D
Selecting / setting means for selecting the beacon reference station located closest to the GPS receiver, and instructing the beacon receiving means as the beacon reference station to receive the correction data to the beacon receiving means. DGPS receiver. 2. The DGPS receiver according to claim 1, wherein the determination unit determines that the longitude of the position of the beacon reference station is:
A first criterion for determining whether the position of the DGPS receiver is within a predetermined range with respect to the longitude, and / or the latitude of the position of the beacon reference station is within a predetermined range with respect to the latitude of the position of the DGPS receiver. Based on a second criterion of whether the beacon reference station
A DGPS receiver for determining whether it is located within a predetermined range from a GPS receiver.