JP2003215229A - High accuracy gps phase measurement method under ground or in building structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high accuracy GPS phase measurement method having resolved instability of initial phase of positioning by phase distance with GPS method capable of positioning by receiving GPS wave in underground or building structure with the same capability as in ground surface. <P>SOLUTION: A measurement start point in a GPS receiver antenna is determined on a known point on coordinates, and instability of the initial phase there is determined to use the value in measurement after that time. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a GPS (Global P
ositioning System: Global Positioning System) In the underground or in the building structure where radio waves do not reach, GP is equivalent to the ground level
The present invention relates to a GPS method that receives S radio waves and enables positioning, and particularly to a phase measurement method that enables highly accurate positioning.

[0002]

2. Description of the Related Art Conventionally, positioning L1 charged waves (1575.42MHz) and L2 charged waves (1227.6MH) emitted from GPS satellites are used.
Since z) is a microwave, it cannot reach underground or inside a building structure, and cannot measure the position by receiving GPS radio waves. In order to solve the problem, in the Japanese Patent Application No. 2001-169834 by the inventor of the present application, in “GPS system usable in underground or in building structure”, independent positioning for measuring range between pseudo satellite and GPS receiver, so-called pseudo distance I proposed the method.

This method receives GPS signals on the ground where GPS radio waves from GPS satellites can be well received,
The signal is demodulated and the signal of each satellite channel is extracted. Next, the signals of each satellite channel are separately re-modulated and guided by coaxial cables or optical fiber cables to a re-radiator provided for each satellite channel underground or in the building structure, and the GPS signal is re-radiated there. To do. Then, when the distance between the re-radiator and the GPS receiver antenna is obtained, G
The position of the PS receiver antenna can be determined.

In the underground or the building structure, the range measured by the GPS receiver, that is, the distance between the GPS satellite antenna and the GPS receiver antenna in the underground or the building structure is the sum of the following items. Distance between GPS satellite antenna and terrestrial GPS receiver antenna Length of signal cable connecting terrestrial GPS receiver and reradiator Distance between reradiator and GPS receiver antenna in underground or building structure

The above can be measured by a terrestrial GPS receiver and is known. Therefore, can be obtained from the range measured by the GPS receiver in the underground or the building structure. Since the position of the GPS receiver antenna in the underground or building structure is known, it is possible to calculate the three-dimensional coordinates of the GPS receiver antenna in the underground or building structure if there are three or more re-radiators. it can. Single difference between satellites (difference between different GPS signals measured by one GPS receiver)
Therefore, four or more re-emitters are required to cancel the clock error of the GPS receiver underground or in the building structure.

When a reference GPS receiver is placed underground or in a building structure, the range of the GPS measured by the mobile GPS receiver and that of the reference GPS receiver are common to each GPS signal. Therefore, if the single-difference between GPS receivers (difference of the same GPS signals measured by different GPS receivers) is calculated, the single-difference between GPS receivers is obtained, as if GP
This is equivalent to the S satellite at the re-emitter position.

The above description will be described in detail using mathematical expressions. First, the observation equation shown in the following mathematical formula 1 holds for the pseudo distance or the phase distance (observation amount) between the satellite antenna i and the receiver antenna α.

[0008]

[Equation 1]

When the pseudorange is used, it is not necessary to consider the indeterminacy of the initial phase, and the following equation 2 is obtained.

[0010]

[Equation 2]

Here, the single-difference between satellites is expressed by the following equation 3, and the noise due to the receiver is eliminated by taking the single-difference between satellites.

[0012]

[Equation 3]

Further, if the single difference between the receivers is taken, the following formula 4 is obtained.

[0014]

[Equation 4]

Here, the single difference between the receivers is expressed by the following equation 5, and the noise due to the satellite is eliminated by taking the single difference between the receivers. When the mobile receiver and the reference receiver are close to each other, the third term on the right side of Expression 2 can be ignored.

[0016]

[Equation 5]

When the double difference between the satellite receivers is taken, the following formula 6 is obtained.

[0018]

[Equation 6]

Here, the double difference between the satellite receivers is expressed by the following equation 7
The noise due to the satellite and the noise due to the receiver are eliminated by taking the double difference between the satellite receivers.
When the mobile receiver and the reference receiver are close to each other, the second term on the right side of Expression 6 can be ignored.

[0020]

[Equation 7]

On the other hand, for the true value of the propagation distance between the satellite i and the ground receiver S, the observation equation shown in the following equation 8 holds.

[0022]

[Equation 8]

Therefore, the single difference between satellites of the true value of the propagation distance is represented by the following formula 9, the single difference between receivers is represented by formula 10, and the double difference between satellite receivers is represented by formula 11.

[0024]

[Equation 9]

[0025]

[Equation 10]

[0026]

[Equation 11]

From the above observation equations (2), (4), (6), (9), (10), and (11), the single difference between the re-radiators in the range between the re-radiator and the receiver is expressed by the following formula (12). The single difference between the re-radiator receivers and the double difference between the re-radiator receivers can be calculated by the mathematical expression 14. (Error omitted)

[0028]

[Equation 12]

[0029]

[Equation 13]

[0030]

[Equation 14]

The second term on the right side of Expression 12 can be calculated from the observed amount of the ground receiver, and the third term can be calculated from the length of the cable connecting the ground receiver and the re-radiator.

Since the following formula 15 is obtained from the coordinates of the re-radiator and the coordinates of the receiver, the single difference between the re-radiators in the range between the re-emitter and the receiver is represented by formula 16, and the single-difference between the receivers is Equation 17, the double difference between the re-radiator receivers is Equation 18.

[0033]

[Equation 15]

[0034]

[Equation 16]

[0035]

[Equation 17]

[0036]

[Equation 18]

By using any one of the equations 12 and 16, the equations 13 and 17, and the equations 14 and 18, the antenna position coordinates of the mobile receiver can be obtained.

[0038]

However, there are multiple unspecified obstacles, wall surfaces, etc. in the underground or in the building structure, which causes multiple reflections. Therefore, the positioning based on the phase distance is far more effective than the positioning based on the pseudo-range described above, and the positioning on the order of centimeters is possible. There is a problem.

The present invention has been proposed to solve the above-mentioned problems, and relates to a GPS system that can receive GPS radio waves and perform positioning in the underground or in a building structure in the same manner as on the ground. An object of the present invention is to provide a high-accuracy GPS phase measurement method that solves the indeterminacy of the initial phase in positioning.

[0040]

In order to solve the above-mentioned problems, the high-accuracy GP in the underground or the building structure of the present invention
In the S-phase measurement method, the measurement starting point in the GPS receiver antenna is taken as the known point of the coordinates, the indeterminacy of the initial phase there is determined, and that value is used for subsequent measurements.

[0041]

Embodiments of the present invention will be described with reference to the drawings.

1. When using two re-radiators Fig. 1 is a layout plan of measuring devices when two re-radiators are used underground or in a building structure. Two re-radiators installed in the basement or near the ceiling 2 in the building structure 4,
4 ', their coordinates are x = -3m and x = + 3m
And The height is z = 2.5 m. It is assumed that the position of the reference GPS receiver antenna 5 is x = −3 m, and the mobile GPS receiver antenna 5 ′ moves from x = −3 m to x = + 3 m. The height from the floor 3 is z = 0.1 m. Signal generators 8 and 8 ′ generate GPS radio waves from GPS satellites received by the terrestrial GPS receiver antenna 6 and the terrestrial GPS receiver 7.
And re-radiate from the re-radiators 4 and 4'provided separately for each satellite channel. This is received by the GPS receiver antennas 5 and 5'and the GPS receivers 9 and 9 '. The double difference between the satellite receivers at this time is geometrically calculated by the monitor personal computer 10 and the fractional part thereof is shown in FIG. As shown in the figure, there are a plurality of coordinate candidates for a given double difference. Therefore, in this case, the position of the mobile GPS receiver antenna 5'cannot be uniquely determined from the double difference.

2. When three re-radiators are used FIG. 2 is a layout plan of measuring instruments when three re-radiators are used underground or in a building structure. Three re-radiators installed in the basement or near the ceiling 2 in the building structure 4,
4 ′, 4 ″ are used, and their coordinates are x = −3 m, x = 0
m and x = + 3 m. The height is z = 2.5 m.
The position of the reference GPS receiver antenna 5 is x = -3 m,
The mobile GPS receiver antenna 5'is from x = -3m to x =-
It shall move to 3m. The height from the floor 3 is z = 0.
It is 1m. Ground GPS receiver antenna 6 and ground GP
GPS radio waves from GPS satellites received by the S receiver 7 are distributed to the signal generators 8, 8 ', 8 ", and re-radiated from the re-radiators 4, 4', 4" provided separately for each satellite channel. To do. This is received by the GPS receiver antennas 5 and 5'and the GPS receivers 9 and 9 '. At this time, two double differences between independent satellite receivers can be obtained. Two re-radiators 4, 4'on the left
And the two re-radiators 4 ', 4 "on the right side, geometrically calculate the double difference between two independent satellite receivers with the monitor personal computer 10, and take the fractional part. As shown in the figure, there is one coordinate candidate for a given set of double differences, so in this case 1
The position of the mobile GPS receiver antenna 5'can be uniquely determined from the double difference of the set.

[0044]

As described above, by using the high-accuracy GPS phase measurement method in the underground or the building structure of the present invention, the normal GPS reception can be performed even in the underground or the building structure where GPS radio waves cannot reach at all. It is possible to obtain the enormous effect of enabling high-precision positioning on the order of centimeters using a machine.

[Brief description of drawings]

FIG. 1 is a layout plan of measuring instruments when two re-radiators are used underground or in a building structure.

FIG. 2 is a layout plan of measuring instruments when three re-radiators are used underground or in a building structure.

FIG. 3 is a graph showing a fractional part of a double difference between satellite receivers in FIG.

FIG. 4 is a graph showing a fractional part of a double difference between satellite receivers in FIG.

[Explanation of symbols]

1 Underground or building structure 2 ceiling 3 floors 4 Reradiator 5 GPS receiver antenna 6 GPS receiver antenna 7 GPS receiver 8 signal generator 9 GPS receiver PC for 10 monitors

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Isshiki             3 Pegasus at 8 Miyuki-cho, Shizuoka City, Shizuoka Prefecture             Inside the net corporation (72) Inventor Hideo Yasuda             3 Pegasus at 8 Miyuki-cho, Shizuoka City, Shizuoka Prefecture             Inside the net corporation (72) Inventor Akira Uchiyama             3 Pegasus at 8 Miyuki-cho, Shizuoka City, Shizuoka Prefecture             Inside the net corporation F-term (reference) 5J062 BB08 CC07 EE05

Claims (2)

[Claims] 1. A basement characterized by taking a measurement starting point in a GPS receiver antenna as a known point of coordinates, determining an indefiniteness of an initial phase there, and using that value for subsequent measurements. High-accuracy GPS phase measurement method in building structures. 2. The high-accuracy GPS phase measuring method in the underground or in the building structure according to claim 1, wherein three or more re-radiators are used.