JP3118056B2 - Transmitter position measuring system, transmitting method and receiving method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transmitter-position-measuring system, and more particularly, about the transmitter position measurement system for measuring the coordinates of the position of the object to be measured by receiving radio waves emanating from the object to be measured
And, for example, a local area wireless communication, in which factory automation, is applied to a home automation.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Application Publication No. Hei.
No. 5550 has "Transmitter position measurement system and transmitter". This is a transmitter position measurement system that can obtain accurate position coordinate information of the DUT within a limited area such as an indoor environment. Is a system for measuring a position of a synchronous circuit and a transmitter of a plurality of reference stations installed in a measurement area by holding a clock serving as a reference in a measurement object. Although this system can track the position in real time, since each reference station requires a synchronization circuit for the pseudo-noise signal,
The circuit configuration becomes complicated.

[0003] Further, the above-mentioned application discloses a position measuring system in which the movement of an object to be measured holding a transmitter is slow or the position does not need to be continuously tracked, such as when the movement is small. By using a matched filter for each pseudo-noise signal without using a synchronous circuit, the circuit configuration is simplified, and a system capable of performing position measurement at certain time intervals is being considered. However, since each reference station calculates the arrival time of the signal transmitted from the transmitter with reference to the clock connected to the computer for calculating the coordinates, the time differs between the reference stations due to delays in the connection cable between the computer and each reference station. If an error occurs, an error will occur in the calculation of coordinates.

[0004] Further, Japanese Patent Application No. 3-1139 previously proposed.
No. 27 “Transmitter position measurement system” is to solve the problem caused by different time difference at each reference station,
A reference transmitter is installed at known coordinates in the measurement area, and a pseudo noise signal different from the measured object is transmitted at the same transmission interval as the measured object and at a different time, and each reference station is set based on this signal. Has proposed a transmitter position measurement system that can calculate the arrival time and reduce the time error in the coordinate calculation of the measured object. However, this system required the installation of a reference transmitter in the measurement area.

[0005]

The present invention has been made in view of the above circumstances, and shows a time reference for a reference transmitter or a clock when a delay time in a connection cable between a computer and each reference station does not matter. A transmitter that calculates the coordinates of the DUT by measuring the delay time of the signal of the other station from the signal that first arrived at each reference station in order to configure the system with a simpler configuration without the need for equipment The purpose of the present invention is to realize a position measurement system, a transmission method, and a reception method.

[0006]

To achieve the above object, the present invention provides (1)
In a position measurement system that measures the position of a device under test in a specific area, the position measurement system holds a transmitter that periodically and intermittently transmits a pseudo noise code signal uniquely assigned to the device under test. DUT, comprising a plurality of reference stations installed in the same area, the reference station receives a pseudo-noise signal from the DUT, and a matched filter for the pseudo-noise signal assigned to the DUT A detector for obtaining a correlation pulse signal from an output from the matched filter;
Measuring means for measuring the arrival delay time of signals detected by other reference stations with reference to the detection time of the signal detected first among the correlation pulse signals obtained by the detector, outgoing machine position measuring system odor coordinates of transmitters you measure the position and the object to be measured of the body are held
The pseudo noise code uniquely assigned to the device under test
Transmitters that periodically and intermittently transmit signals are pseudo-noise
The code cycle time, the reference station installed in the measurement area, and the
The signal is longer than the difference between the longest distance and the minimum distance between the measuring objects.
When adding the guard time, which is the time required for propagation
Be originating interval between, furthermore, after after reaching the (2) before Ki擬 in similar transmitter position measuring system according to claim 1, wherein the noise signal is transmitted, the first signal is a reference station, It has a function of measuring a guard time specified by a transmitter, and ( 3 ) has a transmitter for periodically and continuously transmitting a signal of a pseudo-noise code uniquely assigned to the device under test. 3. The transmitter position measuring system according to claim 1, wherein the time is required for a signal to propagate over a distance equal to or greater than a difference between a longest distance and a minimum distance between a reference station installed in a measurement area and an object to be measured. the use of a pseudo-noise code having a period of more than twice the guard time to the outgoing signal, and further, (4) 1 to claim before Ki擬 similar noise signal is transmitted
3. In the transmitter position measuring system according to any one of (3) to (5), a delay time of a received signal of each reference station measured with reference to a signal that first reaches one of the reference stations, and a reference station-received signal installed in the measurement area. It has a function to compare the guard time, which is the time required for the signal to propagate over the distance of the difference between the longest distance and the shortest distance between the measurement objects, and measure the difference,
When the delay time is longer than the guard time, the delay time is calculated by subtracting the period of the pseudo noise signal from the measured delay time. Hereinafter, a description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an embodiment of a transmitter position measuring system according to the present invention.
1 to 1d are reference stations, 2a to 2d are reception systems, 3 is an object to be measured, 4 is a delay time measuring device, and 5 is a computer. The reference stations 1a to 1d are fixedly installed at, for example, four corners of an indoor ceiling, and the position coordinates of the receiving antennas 2a to 2d are known. In order to uniquely determine the coordinates of the device under test, the antennas of each station should not be on the same plane. The device under test 3, the reference transmitter, and the reference stations 1a to 1d are in line of sight with each other. Therefore, the carriers emitted from the device under test 3 and the reference transmitter propagate through the line of sight and reach the reference stations 1a to 1d. . The transmission carrier of the pseudo-noise signal may be any of radio waves, light, and sound waves. However, in the embodiment described here, radio waves are targeted. When the transmission carrier of the pseudo noise signal is implemented by light or sound waves, for example, a converter to an electric signal may be added.

Each of the reference stations 1a to 1d receives a signal continuously or intermittently transmitted from the DUT 3 and the reference transmitter, obtains a correlated wave output pulse, and transfers it to the delay time measuring device 4. . The delay time measuring device 4 measures the delay time of the correlation pulse from each station with reference to the initially input correlation pulse, and transfers the result to the computer 5.
With the computer 5, the transferred delay time has information and coordinate the reception position of the reference station _{1a~1d (X 1, Y 1,} Z 1) ~
From (X ₄ , Y ₄ , Z ₄ ), the position coordinates (X,
Y, Z) is measured.

FIG. 2 is a block diagram of the transmitter held by the DUT and the receivers of the respective reference stations in the transmitter position measuring system. In FIG. 2, reference numeral 10 denotes a trigger signal generator, and 11 denotes a pseudo noise (PN) signal. Generator, 12 is a frequency converter, 13 is an amplifier, 14 is a transmitting antenna, 15 is a receiving antenna, 16 is an amplifier, 17 is a frequency converter, 18 is a matched filter,
9 is a detector. The device under test has a pseudo noise (PNm) signal generator 11 of a sequence unique to the device under test, and converts the signal into a radio frequency (RF) band (eg, 800 MHz, 1 GHz).
Upconvert to and transmit. The transmission is controlled by the trigger signal generator 10 and is transmitted every T time. At the reference station, the received RF band signal is down-converted, passed through a matched filter 18 that matches the PN code unique to the device under test in the intermediate frequency (1F) band, and then passed through an envelope detector 19 to output the autocorrelation peak output. Get. The matching filter 18 can be generally realized by a SAW device or a CCD. Further, the autocorrelation may be obtained by a convolver instead of the matched filter 18.

FIG. 3 is a diagram showing the correlation detection pulse output of each PN signal obtained by the receiver of each station. The period of the pseudo-noise signal and the timing of the trigger signal generation can be arbitrarily selected. However, since a multipath signal is generated depending on the measurement environment, the signal generation time interval is required only for the time when the multipath signal is sufficiently attenuated. In period 1 in FIG. 3, a received signal is first obtained at the reference station 1a, and subsequently received in the order of the reference stations 1b, 1d, and 1c. At this time, if the delay times t ₂ , t ₃ , and t ₄ of the other station signals from the signal received by the reference station 1a are measured, the coordinates (x, y, z) of the measured object and the coordinates of each reference station (X _1, Y _1, Z ₁₎ relationship between _{~ (X 4, Y 4,} Z 4) is given by the following equation.

[0011]

(Equation 1)

Where c is the speed of light. By solving the above equation for (x, y, z), the coordinates of the measured object are calculated. In period 2 in FIG. 3, since the measured object has moved,
A received signal is first obtained at the reference station 1b, and subsequently received in the order of the reference stations 1c, 1a, and 1d. At this time, the delay time t of the signal of the other station from the signal received by the reference station 1b.
_{When 3} , t ₁ and t ₄ are measured, the coordinates (x, y,
z) and each base station coordinate (X ₁ , Y ₁ , Z ₁ ) to (X ₄ , Y ₄ ,
The relation with Z ₄ ) is given by the following equation.

[0013]

(Equation 2)

By solving the above equation for (x, y, z),
The coordinates of the moving target object are calculated.

[0015] Figure 4 is a block diagram of the delay time measuring circuit for performing a measurement of t ₁ ~t _4, in the figure, 20a to 20d is a waveform shaper, 21,25,27 is OR circuit, 22 denotes a flip-flop ( FF ₀ ), 23 a to 23 d are flip-flops (FF _{1 to} FF ₄ ), 24 is a NOR circuit, 26 a to 26 d
Is a counter, and 28 is a clock signal generator. The waveform of the correlation detection pulse signal from each station is shaped. Signal S
₁ (t) to S ₄ (t), the signal that arrives first is FF ₀₂
2 is set, and counters 26a to 26
The CLR terminal of d becomes low, and clock counting is started. Then the FF ₁ 23a~FF ₄ 23d is reset for each channel at the time when the signal of each channel arrives, next ENABLE signal is low, each of the counter is stopped, the count number C ₁ of the clock pulses at that time, C ₂ , C ₃ and C ₄ are output to the computer. When all the signals of the four channels arrive, the FF ₀ 22 is reset, the respective counters are cleared, and the system is ready for the next measurement. Depending on the measurement environment, multipath fading may occur, and a case may occur where a signal of a level sufficient for measurement does not arrive at all the reference stations. At this time, a carry signal (CRY) indicating the delay time is taken out from the counter, and the FF ₀ 22 can be reset with this signal.

In the counter of the channel where the signal first arrives, the count is 0 because the counter is not activated. In the computer, the number of clocks and the number of counts C ₁ ,
The delay time is calculated from C ₂ , C ₃ , and C ₄ . The channel in which the signal first arrives can be determined by examining the channel whose count number is 0. In the case of period 1 in FIG. 3, since S ₁ (t) arrives first, C ₁ = 0, and t _{2 to} t ₄ are C _{2 to} C _4.
Determined from ₄ . In this case, the measurement accuracy depends on the speed and stability of the clock and the measurement environment. From the delay time and the coordinates of each reference station, the coordinates of the measured object are measured using the above-described formula.

FIG. 5 is a diagram showing another configuration of the transmitter held by the DUT and the receivers of the respective reference stations in the transmitter position measuring system. In FIG. 5, reference numeral 30 denotes a pseudo noise (PN) signal generator.
1 is a frequency converter, 32 is an amplifier, 33 is a transmitting antenna, 34 is a receiving antenna, 35 is an amplifier, 36 is a frequency converter, 37 is a matched filter, and 38 is a detector. In the embodiment shown in FIG. 2, the signal from the device under test is generated intermittently, and a trigger generator is required in the transmitter. However, in the embodiment shown in FIG. Does not require equipment. Other operations are the same as those in FIG.

FIG. 6 is a diagram showing still another configuration of the transmitter held by the DUT and the receivers of the respective reference stations in the transmitter position measuring system. In FIG. 6, reference numeral 39 denotes a delay lock loop, and reference numeral 40 denotes a signal sequence determiner. In addition, the portions having the same functions as those in FIG. 5 are denoted by the same reference numerals. This system is the ash replace a portion of the matched filter and the detector in the delay locked loop 39 and a signal sequence determiner 40. Delay lock loop 3
Reference numeral 9 denotes a synchronization circuit for performing phase tracking of the received PN signal. The signal sequence determiner 40 outputs a signal when a specific signal sequence of the following PN signal is input. The delay lock loop 39 and the signal sequence judging device 40 can be realized by a configuration as shown in FIG.

FIG. 7 is a diagram showing a delay locked loop and a signal sequence judging unit. In FIG.
2 is a loop filter, 43 is a voltage control clock, 44 is a seven-stage feedback shift register, 45 is an EXOR (exclusive OR) circuit, and 46 is an AND circuit. 127 chips of P
It is composed of a 1 △ -type delay locked loop that follows the N signal and a signal sequence determiner realized by inputting the output from each stage of the 7-stage feedback shift register 44 that generates the reference PN signal to the AND gate 46. This is a reception timing output circuit. In this case, since there is only one set of the signal sequence "1111111" in the 127-chip PN signal, the reception timing output is generated when this signal sequence enters, so that the delay time difference between the reference stations is measured. Will be. The calculation of the coordinates of the measured object can be performed in the same manner as the other two systems.

As described above , according to the above system , intermittent position tracking of the object to be measured can be realized by a simple system that does not require a reference transmitter. Further, the measurement error due to the delay time at the time of transmitting the reception timing output signal from each base station is small, which is effective for a system using sound waves. Up
Serial The system object to be measured was one, but using the PN code of different multiple sequences, the reference station by preparing a plurality of matched filters or DLL corresponding to them,
Position tracking of a plurality of objects to be measured is possible.

In the above system , when the delay time in the connection cable between the computer and each reference station does not matter, a device having a time reference such as a reference transmitter or a clock is not required, and a simpler configuration can be achieved. In order to compose a system, a transmitter position measuring system that calculates the coordinates of the measured object by measuring the delay time of the signal of another station from the signal that first arrives at each reference station has been proposed. When this transmitter position measuring system is used in an actual environment, a carrier of a signal transmitted from the measured object such as radio waves, light (such as infrared rays), and sound waves may be blocked by an obstacle. In this case, it is not clear how long to wait for the reception signal to arrive. Further, when a continuous transmission signal is used, for example, when a signal to be received first which is a reference for measuring a delay time of each received signal is lost due to the above-described reason, a signal arriving second is used. Since the delay time is measured based on the reference, the delay time of the signal to arrive first may be incorrectly measured, which may cause a large error in position estimation. In such a case, the following embodiment may be used. That is , a method of transmitting a pseudo-noise signal emitted from the device under test ,
And receiving how of the emitted signal by the transmission method.

FIG. 8 shows a transmission signal waveform for explaining a transmission method applied to the system of the present invention . After transmitting a pseudo noise signal having a period T unique to the device under test, a guard time T
g is provided. Here, the guard time Tg is Tg = (Lmax-Lmin) / c, where Lmax is the maximum distance between the reference station and the measured object in the area to be measured, and Lmin is the minimum distance.
(C: carrier propagation speed). Lmax and Lm
In varies depending on the environment to be measured. For example, when reference stations 52a to 52d are installed in a cubic indoor 51 as shown in FIG. 9 and the measured object 53 is on the bottom surface, a diagonal line as shown in FIG. May be selected as Lmax and the minimum distance between the base and the reference station as Lmin. In order to generate the signal of FIG. 8, the trigger signal generator shown in the embodiment (FIG. 2) of the transmitter of the transmitter position measurement system described above may be designed for the measurement area targeted. An example is shown in FIG.

In FIG. 10, a 127-bit M-sequence code generator having a feedback tap (3, 7) is controlled by a trigger circuit including a counter and a flip-flop using a 7-bit feedback shift register. In the figure, 61 is an OR circuit, 6
2 is a flip-flop (FF1), 63 is a counter,
64 is a flip-flop (FF2), 65 is a clock signal generator, 66 is an OR circuit, 67 and 68 are AND circuits, 69 is a shift register, and 70 is an EX-OR circuit.

At the same time that the FF1 and FF2 are reset by the reset signal, the shift register 69 is loaded with an initial value (1111111). F when reset signal is input
Since the output of F2 is Low, no clock signal is input to the shift register 69, and the value of the shift register 69 is kept at (1111111). Therefore, the output of FF1 becomes Hi, and the counter 63 starts counting clocks. When the count number Cg corresponding to the guard time Tg occurs as a carry, the output of the FF2 becomes Hi and the generation of the pseudo noise signal is started. When the signal is generated for one cycle, the signal sequence in the register returns to the initial value (1111111) again, and the AND gate output becomes Hi again. Therefore, the generation of the pseudo noise signal is stopped, and the process proceeds to the measurement of the guard time. It is clear that the signal of FIG. 8 can be generated in this way.

Since the guard time Tg of the signal is larger than the maximum value of the delay time that can be measured by the delay time measuring device, the signal of FIG. 8 is used to measure the time after the first signal is received by the receiver. If no signal is received at some reference stations, even if the time exceeds Tg, then the signal to be received at those stations is deemed to be lost,
The delay time measuring device can be reset and the signal measurement of the next cycle can be started. Receiving method that meets such a function is realized by using a delay time measuring device shown in the embodiment of FIG. 11.

FIG. 11 shows a system suitable for the system according to the second aspect of the present invention.
FIG. 3 is a diagram showing an embodiment of a delay time measuring device for realizing a receiving method used . In the figure, reference numerals 71a to 71d denote waveform shapers, 7
2 is an OR circuit, 73a to 73d and 74 are flip-flops, 75a to 75e are counters, and 76 is a clock signal generator. The roles of the counters 1 to 4 and FFs 1 to 4 are the same as in FIG.
The difference is the addition of. Of the signals arriving at the reference station, the output of the FF5 becomes Hi at the earliest signal, and all counters start time measurement. The counter 5 counts the number of clocks corresponding to the guard time and generates a carry signal. The output of the FF 5 becomes Low, each counter stops counting, and each count number at that time is used as a delay time for position measurement of the measured object. If periodic and to continuously generate the oscillation signal as described above in the receiver position measurement system does not perform the generation control of the pseudo-noise signal by the trigger circuit, the period of the pseudo-noise signal as claimed in claim 3, wherein It must be selected according to the target measurement environment. Assuming that the period of the pseudo noise signal to be selected is T, T
Select so that ≧ 2 · Tg. As an example, considering the case where a sound wave is used as a carrier (the sound speed is 300 m / s), the chip rate of the pseudo noise signal is 6 kHz, and (Lmax-Lmin) = 20 m, the number of chips N of the required pseudo noise signal is N
N ≧ (20/30) · 6000 = 400 When an M-sequence code is used as a pseudo-noise code, for example,
Codes of 511 chips can be used. A pseudo-noise signal generator that generates this code can be realized using, for example, a feedback shift register as shown in FIG. In the figure, 81
Is an EX-OR circuit, and 82a to 82i are flip-flops.

FIG. 13 shows that the period T of the pseudo noise signal is 2 · T
An example of a detection signal from each reference station when g is set is shown. Each pulse signal is a signal whose waveform has been shaped by a delay time measuring device. In this example, an example is shown in which a signal to be received is lost in the reference station 1 closest to the measured object after the signal transmission from the measured object. At this time, the first signal detected is
Since the signal is from the reference station 2, the signal detection delay time of another station is measured based on this signal. Claim 1
In the measurement method described above, since the delay time at the reference station 1 is measured as t ₁ , the delay time at the reference station 1 closest to the measured object is measured to be the longest, and a large error occurs in the calculation of the position of the measured object.

Here, when the time difference t ₀ between the missing signal (indicated by a dotted line) that should have been detected by the reference station 1 and the detection pulse signal of the reference station 2 that has become the time reference for the delay time measurement is Tg at the maximum. Can be considered. Further, since the signal of the next cycle detected by the reference station ₁ must be measured as t ₁ > Tg, the maximum value of (t ₀ + t ₁ ) is 2 · Tg. Therefore, the period of the pseudo noise signal is set to T ≧ 2 · Tg, the measured delay time is compared with Tg, and if t ≧ Tg, the signal is lost by setting (t−T) to the delay time. In this case, the correct delay time is measured (claim 4 ).

FIG. 14 is a diagram showing a delay time measuring device which is an embodiment of the receiving method according to the fourth aspect . In the figure, 91a
91d is a waveform shaper, 92 is an OR circuit, 93a to 93
d and 94 are flip-flops, 95a to 95e are counters, 96a to 96d are count number comparing and correcting units, and 97 is a clock signal generator. The operation principle of the circuit is the same as that of FIG. 11 except for the counter 5 and the count number comparison / correction unit. In FIG. 14, the counter 5 counts the number of clocks corresponding to the period of the pseudo noise signal and generates a carry signal. Therefore, the counters 1 to 4 for measuring the delay time for each period of the pseudo noise signal are reset. The count number comparison and correction unit compares the counter output value Ci (C _{1 to} C ₄ ) at each station with the count number Cmax of the clock corresponding to the maximum delay time Tg. As shown in FIG. 15, when Ci is smaller than Cmax, Ci is used for position calculation as it is.
i- _CT ). Here, C _T is the number of clocks corresponding to the period T of a pseudo-noise signal, in the example of FIG. 13 C _T =
2 · Cmax. The clock frequency is constant and Cm
Since ax is fixed in the target area and C _T is also fixed in the system, the function of the count number comparison and correction unit can be realized on software of a computer (see FIG. 1) that actually performs position calculation.

[0030]

As apparent from the above description, the present invention has the following effects . The DUT holds the transmitter of the pseudo-noise signal, transmits the pseudo-noise signal intermittently, receives the signal at a plurality of reference stations, and uses a matched filter corresponding to the pseudo-noise signal sequence to generate a correlation pulse. to obtain a signal, by obtaining the relative arrival time delay of each received signal, a simple system that does not use a reference source station and synchronization circuit to track the position coordinates of intermittent object to be measured becomes possible shea
In the system, (1) when a received signal is lost in some reference stations, a signal to be received by the reference station can be received and a signal can be generated. (2) Even if a received signal is lost in some reference stations, measurement of the delay time of the next emitted signal can be started accurately. (3) In a system for measuring the position of a transmitter that continuously transmits a pseudo-noise signal, it is possible to generate a signal that can determine the presence or absence of a signal loss at the time of reception at a reference station. (4) When the received signal is lost at some reference stations, the delay time of the transmitted signal can be measured without causing an error due to the loss.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a transmitter position measuring system according to the present invention.

FIG. 2 is a configuration diagram of a transmitter held by an object to be measured and a receiver of each reference station in the transmitter position measuring system.

FIG. 3 is a diagram showing a correlation detection pulse output of each PN signal obtained by a receiver of each station.

FIG. 4 is a diagram illustrating a delay time measurement circuit.

FIG. 5 is another configuration diagram of the transmitter held by the DUT and the receiver of each reference station in the transmitter position measuring system.

FIG. 6 is a diagram showing still another configuration of the transmitter held by the measured object and the receivers of the respective reference stations in the transmitter position measuring system.

FIG. 7 is a diagram illustrating a delay locked loop and a signal sequence determiner.

FIG. 8 is a diagram showing a transmission signal waveform.

FIG. 9 is a diagram illustrating a reference station and a device under test (a transceiver) installed indoors.

FIG. 10 is a diagram showing a trigger signal generator.

FIG. 11 is a diagram showing a delay time meter measuring device.

FIG. 12 is a diagram illustrating a feedback shift register.

FIG. 13 is a diagram illustrating an example of a detection signal from each reference station.

FIG. 14 is a diagram showing another delay time measuring device.

FIG. 15 is a diagram showing a flowchart of position calculation based on the count output.

[Explanation of symbols]

1a-1d: Reference station, 2a-2d: Receiving system, 3 ...
Object to be measured, 4 ... delay time measuring instrument, 5 ... computer.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01S 5/00-5/14 G01S ⁷ /00-7/42 G01S 7/52-7/66 G01S 13/00-13 / 95 G01S 15/00-15/96 H04B 7/00-7/26 H04Q 7/00-7/04

Claims (4)

(57) [Claims] 1. A position measurement system for measuring a position of an object to be measured in a specific area, wherein the position measurement system periodically and intermittently transmits a pseudo noise code signal uniquely assigned to the object to be measured. A test object that holds a transmitter to perform the test, and a plurality of reference stations installed in the same area, the reference station receives a pseudo noise signal from the test object, and the pseudo noise assigned to the test object. A matched filter for the signal, a detector for obtaining a correlation pulse signal from an output from the matched filter, and among the correlation pulse signals obtained by the detector, a detection time of a signal detected first, and and a measuring means for measuring the arrival time delay of the signal detected by the reference station, outgoing machine position measuring <br/> system you measure the coordinates of the transmitter position and the object to be measured of the object to be measured is held Smell , Assigned to specific said the object to be measured
Transmitting pseudo-noise code signals periodically and intermittently
Machine is installed in the measurement area with the period time of the pseudo-noise code.
Distance between the longest distance and the minimum distance between the reference station and the DUT
Guard time, which is the time required for the signal to propagate beyond the separation
A transmission characterized by setting the transmission interval to be the time obtained by adding
Transmitter position measurement system. 2. A method according to claim 1 which before Ki擬 similar noise signal is transmitted
In the transmitter position measuring system described above, after the first signal reaches one reference station, the transmitter has a function of measuring a guard time specified by the transmitter.
Machine position measurement system. Wherein the at transmitter position measuring system according to claim 1 or 2, wherein having a transmitter for transmitting cyclically and continuously the signal of the pseudo-noise code assigned uniquely to the measured sample, the measurement region A pseudo-noise code having a period of at least twice as long as the guard time, which is the time required for the signal to propagate over the distance between the longest distance and the minimum distance between the reference station and the DUT installed at Dispatch characterized by using
Machine position measurement system. 4. The method of claim 1, before Ki擬 similar noise signal is transmitted
In the transmitter position measuring system according to any one of the first to third aspects, a delay time of a reception signal of each reference station measured based on a signal that first reaches one of the reference stations, and a reference station installed in the measurement area. It has a function of comparing a guard time which is a time required for a signal to propagate over a distance equal to or longer than the difference between the longest distance and the shortest distance between the measured objects, and has a function of measuring the difference. If it is larger than the measured delay time, the transmitter has a function to correct it by subtracting the period of the pseudo noise signal from the measured delay time.
Fixed system.