JPH09288159A - Method and equipment for interference positioning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy determination of an integral value of a carrier frequency by a method in which a distance between a receiving antenna of a fixed receiver and a receiving antenna of a movable receiver is set to be a half wavelength of the carrier frequency or less. SOLUTION: A distance (m) between a receiving antenna 20 of a fixed receiver 2 fixed at a reference point A and a receiving antenna 30 of a movable receiver 3 at an adjacent point B is set to be m<(1/2).λ when one wavelength of a carrier frequency from a GPS satellite 1 is made λ. When an optical-path difference between the fixed receiver 2 and the movable receiver 3 is within a 1/2 wavelength, in other words, a wavelength difference (difference in the number of wavelengths) made integral can be determined automatically as 0, that is, integer ambiguity can be determined as 0. In this way, the integer ambiguity can be determined very easily and it is possible to improve operability sharply and to lessen the possibility of causing false measurement. Therefore relative positioning in centimeters can be executed even by general users.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference positioning method and an apparatus therefor using a carrier phase from a communication satellite, and more particularly to determining an integer value of the carrier phase.

[0002]

2. Description of the Related Art An interferometric positioning method using a carrier phase from a GPS satellite is a positioning method used for relative positioning such as GPS surveying (that is, the position of an unknown point is determined by the distance and direction from a certain reference point). That is, the principle is that G is applied to both ends of a so-called baseline (a straight line between the reference point and the positioning point).
The PS receiver is placed, and the path difference is measured by the phase difference of the carrier frequencies from the GPS satellites received by each GPS receiver. This path difference is uniquely determined by the position of the satellite and the baseline vector (length and direction), and the position of the satellite is obtained from orbit information from the satellite. Therefore, the baseline vector can be obtained by measuring the path difference. Thus, relative positioning can be performed.

However, what is required in such an interference positioning method is the determination of an integer value of the carrier phase when obtaining the path difference. That is, since the carrier frequency from the GPS satellite is as short as 19 cm in the L1 band and 24 cm in the L2 band, when the path difference is obtained by the number of wavelengths and the phase difference, the wavelength on which the path difference is (integer value) is first. Have to decide. This integer wave number ambiguity is referred to as integer ambiguity in this specification, and the determination of the integer value is referred to as the determination of integer ambiguity.

In this type of conventional interferometric positioning method, the so-called known point method or antenna swapping method is used to determine the integer ambiguity. FIG.
FIG. 3 is a diagram for explaining a known point method in a conventional interferometric positioning method, where 1 is a GPS satellite, 2 is a fixed (F) receiver fixed to a reference point A whose position is known in advance,
Reference numeral 3 is a moving (M) receiver placed at a known point C which is a relative distance L (known distance) away from the reference point A. In addition,
In this specification, for convenience of explanation, all the explanations are made in two dimensions and one GPS satellite is explained, but at least four (one obtains time correction information) for actual positioning. 3D positioning is performed by receiving signals from GPS satellites.

In this known point method, the F receiver 2 is placed at the reference value point A, and the M receiver 3 is placed first at the known point C, the positions of which are known exactly, and the known distance L is used for M. The integer ambiguity of the receiver 3 is determined, the M receiver is moved to an unknown measurement point (not shown) while keeping the reception from the satellite thereafter, and the path difference is calculated using this integer ambiguity. Is measured and the baseline vector from the reference point A is obtained.

FIG. 4 is a diagram for explaining the antenna swapping method in the conventional device. In the antenna swapping method, the F receiver 2 is first placed at the reference point A, and the M receiver 3 is placed at the temporary point (appropriate unknown point) D for observation.
Next, the M receiver 3 is placed at the reference point A and the F receiver 2 is placed at the temporary point D for observation. Note that the heights of the antennas of the F receiver 2 and the M receiver 3 must be exactly matched.

In the first observation, the AB baseline is measured with the F receiver 2 as a reference, and the integer ambiguity causes the point B to become a multiple solution. Also in the next observation with the antennas replaced, the baseline BA is also measured with the F receiver 2 as a reference, so point A is a multiple solution, but the GPS satellites with reference to the F receiver 2 Movement of GPS satellites due to difference in direction and passage of time (1
→ Due to 1a), the intervals of each multiple solution are slightly different. However, since the same baseline is used between AB even after the antennas are exchanged even in the first observation, it is possible to find a matching baseline solution in two multiple solutions, which determines the integer ambiguity of the M receiver 3. . The details of these conventional techniques are disclosed in, for example, "GPS-Precision Positioning System by Artificial Satellite" edited by The Geodetic Society of Japan, "Guide for GPS survey and baseline analysis", and the like.

[0008]

As described above, in the conventional interference positioning method, the integer ambiguity is determined by the existing point method or the antenna swapping method. In the existing point method, however, the reference point A is determined as described above. A point (C) whose relative distance and direction are known is required. Therefore, point (C)
Will be surveyed in advance, or a point that has already been surveyed, such as a triangular point, will be used as the existing point (C), but surveying will be expensive and time-consuming, and if you are using a point that has already been surveyed. , The available points are limited.

Further, in the antenna swapping method, although no existing spot is required, it is necessary to prepare an antenna of the same height and replace this antenna, which complicates the surveying procedure and leads to erroneous surveying. It is easy to do, and therefore there is a problem that it is not preferred by surveying engineers.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an interference positioning method and an apparatus therefor which can easily determine an integer value of a carrier frequency.

[0011]

According to the interferometric positioning method of the present invention, at the start of positioning, a carrier frequency of 1 is set between the receiving antenna of a fixed receiver and the receiving antenna of a mobile receiver.
/ Wavelength less than or equal to 2 and automatically set the integer wave number difference between the carrier phase received by the fixed receiver and the carrier phase received by the mobile receiver to 0, and then moving the mobile receiver to the positioning point to perform positioning. It is characterized by having.

Further, the interferometric positioning apparatus of the present invention uses the fixed receiver so that the integer wavenumber difference between the carrier phase received by the fixed receiver and the carrier phase received by the mobile receiver is automatically set to 0 at the start of measurement. It is characterized in that it is provided with a configuration capable of setting the distance between the receiving antenna and the receiving antenna of the mobile receiver to ½ wavelength or less of the carrier frequency.

The determination of the so-called integer ambiguity is necessary because the path difference between the fixed receiver and the mobile receiver 1 is usually 1/2 wavelength or more at the start of positioning.
This is because it is necessary to determine which wavelength the path difference should be counted as. However, if the path difference between the fixed receiver and the mobile receiver is within 1/2 wavelength at the start of positioning, the integer wavenumber difference can be determined to be 0, that is, the integer ambiguity can be determined to be 0. In the present invention, the integer ambiguity is automatically determined by setting the distance between the antennas of both receivers to ½ wavelength or less as described above.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining the operation principle of the present invention. In the figure, 1 is a GPS satellite, and 2 is a GP fixed to a reference value point A whose position is known in advance.
S fixed (Fix) receiver, 3 is a move receiver placed at an adjacent point B adjacent to the reference point A, and 20 is a GP of the receiver 2.
The S receiving antenna, 30 is a GPS receiving antenna of the receiver 3, and the distance m between the antenna 20 and the antenna 30 is m.
Is set to m <(1/2) · λ, where λ is one wavelength of the carrier frequency from the GPS satellite.

Next, the principle of the present invention will be described. In the conventional device, it is necessary to determine the so-called integer ambiguity as described in FIG.
Since the path difference between the GPS mobile receiver 3 and the GPS receiver 3 is usually 1/2 wavelength or more, it is necessary to first determine which wavelength the path difference is on. However, GP
If the path difference between the S fixed receiver 2 and the GPS mobile receiver 3 is within 1/2 wavelength, the integerized wavelength difference (difference in the number of wavelengths) is automatically 0, that is, the integer ambiguity. Can be determined to be 0. The present invention utilizes this principle.

The distance m between the antennas of both receivers is
Needless to say, unlike the known point method, the adjacent point B where m <(1/2) · λ does not need to be accurately positioned, and it is also necessary to replace the antenna like the antenna swapping method. Absent. In addition, a recent GPS receiver has a size of 50 × 5 when equipped with an antenna.
Those with a size of 2 × 19 (mm) have been developed (for example, H.Hojo et al ,: GPS Sensor for a Variety of Appl.
ication, ION GPS-94 Proceedings, PP1087 ~ 1095, Sep
t.1994, Salt Lake City, USA), and as described above, the carrier frequency from the GPS satellite has a wavelength of 19 in the L1 band.
Since the wavelengths in the cm and L2 bands are 24 cm, it is easy to reduce the inter-antenna distance m to 1 / 2λ or less. Note that when both GPS receivers are adjacent to each other, a multipath preventing reflection plate, that is, a reflection plate (ground plane) having a diameter of about 30 cm that can obtain high positioning accuracy in millimeter units cannot be attached. Since the positioning accuracy in centimeters can be obtained without installing it,
Sufficient for general surveying applications.

FIG. 2 is a block diagram showing an outline of an apparatus configuration in one embodiment of the invention of the present invention.
The same reference numerals denote the same or corresponding parts, 21 and 31 are display control devices, 22 is a reference point information transmitter, and 32 is a reference point information transmitter.
Is a reference point information receiver. The interferometric positioning device according to the present embodiment includes a display control device 21 for displaying the positioning information on the GPS fixed receiver 2 as shown in the schematic view of FIG.
A reference point information transmitter 22 for transmitting the positioning information of the reference point (A) to the GPS mobile receiver is provided, and the GPS mobile receiver 3 has a display control device 31 for displaying the positioning information.
And a reference point information receiver 32 that receives the reference point information sent from the transmitter 22.

Then, as shown in FIG. 1, the mobile receiver 3 is first placed at the adjacent point B, and the antenna distance m is 1 / 2λ.
It is set to a smaller value and the integer ambiguity is automatically determined to be 0. While both GPS receivers continue to receive the carrier frequency from the GPS satellite 1, as shown in FIG. Take to E and integer wavenumber difference and phase difference of carrier phase received by both GPS receivers,
From the position information of the GPS satellite 1 and the position information of the reference point A, the relative position information of the positioning point E is output to the display control device 31. Regarding the relative positioning, the above-mentioned "GP
The detailed description is given in "Guide for S-Survey and Baseline Analysis", and the same description can be applied in the present embodiment as well, and thus detailed description thereof is omitted here.

In the above embodiment, the interferometric positioning method and apparatus using GPS are explained.
Needless to say, it is not limited to PS and may use another system such as GLONASS.

[0020]

As described above, the interference positioning method and the apparatus thereof according to the present invention can determine the integer ambiguity extremely easily, can greatly improve the operability, and can cause erroneous measurement. Sex can be significantly reduced. Therefore, general users can perform relative positioning in units of centimeters, which was conventionally thought to be handled only by a surveying engineer. In addition, the price of GPS receivers has been decreasing year by year, as seen in car navigation systems, for example.
As the size and size of transmitters and receivers are becoming lower / smaller as seen in PHS telephones, it is considered that such an interferometric positioning device will be further lower in price / smaller. Can be used in place of a tape measure to provide new applications.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a block diagram showing an outline of a device configuration according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining a conventional known point method.

FIG. 4 is a diagram for explaining a conventional antenna swapping method.

[Explanation of symbols]

 1 GPS Satellite 2 GPS Fixed Receiver 3 GPS Mobile Receiver 20 GPS Receiver Antenna of Receiver 2 21 Display Control Device 22 Reference Point Information Transmitter 30 GPS Receiver Antenna of Receiver 3 31 Display Control Device 32 Reference Point Information Receiver A Reference point B Adjacent point C Known point D Temporary point E Positioning point

Claims (2)

[Claims] 1. A fixed receiver is fixed to a reference point whose position is known in advance, a mobile receiver is moved to a positioning point, and a carrier phase from a satellite is received by each receiver,
In the interferometric positioning method that calculates the path difference from the satellite of each receiver based on the received carrier phase difference (integer wave number difference and phase difference) and uses this path difference to perform relative positioning of the positioning point from the reference point , The wavelength between the receiving antenna of the fixed receiver and the receiving antenna of the mobile receiver is equal to or less than 1/2 wavelength of the carrier frequency, the carrier phase received by the fixed receiver and the carrier received by the mobile receiver. An interferometric positioning method comprising means for automatically positioning the integer wave number difference of the phases and then moving the mobile receiver to the positioning point to perform positioning. 2. A fixed receiver is fixed to a reference point whose position is known in advance, a mobile receiver is moved to a positioning point, and a carrier phase from a satellite is received by each receiver,
In the interferometric positioning device that calculates the path difference from the satellite of each receiver based on the received carrier phase difference (integer wave number difference and phase difference), and performs relative positioning of the positioning point from the reference point by this path difference, the fixed reception Of the reception antenna of the fixed receiver and the reception antenna of the mobile receiver so that the integer wave number difference between the carrier phase received by the receiver and the carrier phase received by the mobile receiver is automatically set to 0 at the start of measurement. The interferometric positioning device is characterized in that it has a configuration in which the distance can be set to ½ wavelength or less of the carrier frequency.