JP2009281896A - Displacement measurement device and method by gps with rtk anomalous positioning data processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement measurement device for the sea surface by GPS capable of removing an anomalous value even if the anomalous value is generated in the measurement data by the RTK method. <P>SOLUTION: The displacement measurement device which inputs the sea surface positioning data calculated in the RTK calculation part 11 based on the measurement data from a standard station 1 and an observation station 2 into a data analysis part 17 via a data selection part 15, and extracts the wave, tidal height and tsunami, includes a PVD calculation part 12 for obtaining the wave components using a high precision displacement detection method for obtaining the displacement component based on the single positioning method from the measurement data of the observation station, a tidal height prediction part 13 for obtaining a predicted tidal height using a tidal height prediction formula determined based on the past data, and an anomalous determination part 16 for subtracting the wave components from the sea surface positioning data and determining whether an anomalous occurs or not in the sea surface positioning data based on the subtracted value. When it is determined that the anomalous occurred, the predicted tidal height without aberration predicted in the tidal height prediction part is inputted in the data selection part in place of the measured sea surface positioning data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a displacement measuring apparatus and displacement measuring method using GPS accompanied by RTK abnormality positioning data processing.

The RTK (Real Time kinematic) method is a positioning method that uses GPS (Global Positioning System) to determine the three-dimensional position of a measurement object (hereinafter referred to as a measurement point) in real time. Tsunami / wave observation using ocean observation buoys It is also used. This RTK method measures the carrier phase at the measurement point while referring to the measurement value based on the carrier phase from the GPS satellite at the reference point whose latitude, longitude and height are known in advance. In this method, the fluctuation component of the measurement point is obtained and the three-dimensional position of the measurement point is accurately measured. By using this RTK method, it is possible to observe tsunamis and waves in real time (see Non-Patent Document 1).
"Development of GPS Tsunami Meter-Ofunato City Practical Experiment" (The IEICE Transactions Vol.J84-B No.12 December pp2227-2235) (December 2001)

  By the way, the RTK method is a positioning method that can determine the three-dimensional position of an observation point (measurement target point) in real time, and the measurement error is usually extremely high, about several centimeters. However, when GPS data that is strongly influenced by the ionosphere or troposphere is used for RTK positioning, an integer ambiguity determination error may occur, and the measured value may jump beyond several centimeters. .

  That is, in general, in GPS positioning software incorporating the RTK method, a fixed solution (FIX solution), a float solution (FLOAT solution), a D-GPS solution or a single positioning is performed according to the acquisition status of GPS satellite data and correction data. One of the solutions is output. When data is output as a fixed solution, it is the most accurate and reliable. However, even when it is output as a fixed solution, a jump phenomenon, so-called jump, may occur in the operation result due to an integer value ambiguity determination error.

  In addition, since the result of positioning by the RTK method includes a short-period wave component, it is necessary to apply a low-pass filter to extract the tsunami component from this. However, if a low-pass filter is applied to data that contains jump values, that is, abnormal values, the waveform will appear as if a tsunami has arrived. .

  Therefore, the present invention relates to a sea level displacement measuring device and a sea level displacement measuring method by GPS that can remove an abnormal value even if an abnormal value occurs in the measured data by the RTK method, in other words, with RTK abnormal positioning data processing. An object of the present invention is to provide a displacement measuring device and a displacement measuring method using GPS.

In order to solve the above-mentioned problem, a displacement measuring apparatus using GPS according to claim 1 of the present invention provides measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground, and a predetermined sea area. A device for measuring sea surface displacement based on measurement data obtained by an observation GPS receiver (hereinafter referred to as an observation station) installed in a moored observation buoy,
A first calculation unit that inputs reference measurement data from the reference station and observation measurement data from the observation station and obtains sea level data of the observation station by a real-time kinematic method (RTK);
A second computing unit that obtains sea surface displacement as a wave component by a high-precision fluctuation detection method that inputs observation measurement data from an observation station and obtains a fluctuation component using a single positioning method;
A tide level prediction unit that inputs sea level position data obtained by the first calculation unit and predicts a tide level using a tide level prediction formula that is determined based on past sea level position data and updated over time;
An addition unit for obtaining predicted sea level position data by adding the sea level displacement obtained by the second calculation unit to the predicted tide level obtained by the tide level prediction unit;
A data selection unit that inputs the predicted sea surface position data obtained by the addition unit and the sea surface position data obtained by actual measurement obtained by the first calculation unit and outputs any one of the sea surface position data;
The actual sea level position data obtained by the first computing unit and the sea level displacement obtained by the second computing unit are input to obtain a subtraction value which is the difference between the two and the subtraction value or the differential of the subtraction value An abnormality determination unit that determines whether or not the sea level position data obtained by the first calculation unit based on the value is abnormal,
In addition, when the abnormality determination unit determines that the data is abnormal positioning data, the tide level prediction formula is not updated when the predicted tide level is calculated by the tide level prediction unit, and the determination result is used as the above data. It outputs to a selection part, and it is comprised so that the predicted sea surface position data obtained in the said addition part may be output.

The GPS displacement measurement method according to claim 2 is installed in measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation buoy moored in a predetermined sea area. A first calculation step for obtaining sea surface position data by a real time kinematic method (RTK) using measurement data obtained by an observation GPS receiver (hereinafter referred to as an observation station);
A second calculation step for obtaining sea level displacement as a wave component by a high-precision fluctuation detection method that inputs observation measurement data from an observation station and obtains a fluctuation component using a single positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is abnormal positioning data in this abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. This is a method for outputting the predicted sea surface position data obtained in (1).

The GPS displacement measuring device according to claim 3 is installed in measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation buoy moored in a predetermined sea area. A device for measuring sea surface displacement based on measurement data obtained by an observation GPS receiver (hereinafter referred to as an observation station),
A first calculation unit that inputs reference measurement data from the reference station and observation measurement data from the observation station and obtains sea level data of the observation station by a real-time kinematic method (RTK);
A second calculation unit that inputs the reference measurement data from the reference station and the observation measurement data from the observation station, and obtains the sea surface displacement that is a wave component by a precise fluctuation detection method that obtains the fluctuation component using a relative positioning method;
A tide level prediction unit that inputs sea level position data obtained by the first calculation unit and predicts a tide level using a tide level prediction formula that is determined based on past sea level position data and updated over time;
An addition unit for obtaining predicted sea level position data by adding the sea level displacement obtained by the second calculation unit to the predicted tide level obtained by the tide level prediction unit;
A data selection unit that inputs the predicted sea surface position data obtained by the addition unit and the sea surface position data obtained by actual measurement obtained by the first calculation unit and outputs any one of the sea surface position data;
The actual sea level position data obtained by the first computing unit and the sea level displacement obtained by the second computing unit are input to obtain a subtraction value which is the difference between the two and the subtraction value or the differential of the subtraction value An abnormality determination unit that determines whether or not the sea level position data obtained by the first calculation unit based on the value is abnormal,
In addition, when the abnormality determination unit determines that the data is abnormal positioning data, the tide level prediction formula is not updated when the predicted tide level is calculated by the tide level prediction unit, and the determination result is used as the above data. It outputs to a selection part, and it is comprised so that the predicted sea surface position data obtained in the said addition part may be output.

Further, the GPS displacement measurement method according to claim 4 is installed in measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation buoy moored in a predetermined sea area. A first calculation step for obtaining sea surface position data by a real time kinematic method (RTK) using measurement data obtained by an observation GPS receiver (hereinafter referred to as an observation station);
A second calculation step for obtaining sea level displacement, which is a wave component, by inputting a reference measurement data from a reference station and an observation measurement data from an observation station and obtaining a fluctuation component using a relative positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is abnormal positioning data in this abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. This is a method for outputting the predicted sea surface position data obtained in (1).

  According to the displacement measuring apparatus and displacement measuring method described above, the sea wave position data obtained by the real-time kinematic method is subtracted from the wave component obtained by the high-precision fluctuation detection method using single positioning or the precise fluctuation measuring method using relative positioning. At the same time, based on this subtraction value or the time change rate of the subtraction value, it is determined whether or not an abnormality such as a jump has occurred in the sea surface position data, and if it is determined that there is an abnormality, Since normal sea level position data obtained by adding wave components to the tide level obtained from the prediction unit is used, no abnormality is detected in the data. Therefore, when the tsunami is monitored, the abnormal data is not erroneously detected as a tsunami, so that the tsunami warning can be prevented from being erroneously issued.

[Embodiment 1]
Hereinafter, a displacement measurement device and displacement measurement method using GPS with RTK abnormality positioning data processing according to Embodiment 1 of the present invention [In short, a sea surface displacement measurement device (also referred to as a sea surface displacement measurement system) using GPS and sea surface displacement] Measurement method] will be described with reference to FIGS.

  This sea level displacement measuring device and sea level displacement measuring method uses GPS (Global Positioning System) to measure sea level displacement, specifically, wave, tide level and tsunami with high accuracy. Specifically, a real-time kinematic [hereinafter referred to as RTK (Real Time kinematic)] method, that is, a relative positioning method using a carrier phase (also referred to as an interference positioning method) is adopted, and a single precise fluctuation detection method called a PVD method [ Hereinafter, it is referred to as a PVD (Point Precise Variance Detection) method and also referred to as a high-precision variation detection method (see JP 2001-147263 A)].

  If this PVD method is explained briefly (details will be described later), it is a method for obtaining fluctuation components using a single positioning method by inputting observation data from an observation station. In this method, the displacement can be measured with the same accuracy as the RTK method.

First, a schematic configuration of the sea level displacement measuring apparatus will be described with reference to FIG.
This sea level displacement measuring device is composed of a reference GPS receiver (hereinafter referred to as a reference station) 1 installed on the ground and an observation GPS receiver (hereinafter referred to as an observation station) 2 installed in an observation buoy moored in a predetermined sea area. Based on the obtained measurement data (also referred to as positioning data), the sea level displacement in the predetermined sea area is measured.

  This sea level displacement measuring device inputs the reference measurement data from the reference station 1 and the observation measurement data from the observation station 2 and obtains the sea surface position data of the observation station by the RTK method. RTK calculation unit (first calculation unit) 11 A PVD calculation unit (second calculation unit) 12 that inputs observation measurement data from the observation station 2 and obtains a sea surface displacement amount that is a wave component (also a short period component) by the PVD method, and the RTK calculation unit 11 The sea level position data (this includes each component of tide level, waves, and tsunami) entered in step 1, and the sea level for the past predetermined time [for example, about several tens of minutes (about 20 to 30 minutes)] A tide level prediction formula determined based on the position data, for example, a quadratic polynomial with time as a variable (of course, it may be first order or third order, but the second order polynomial is optimal), at the time of the previous (future) time [ example A tide level prediction unit 13 that predicts a tide level in a few seconds with an interval of 1 second (also a sampling interval), and a wave component obtained by the PVD calculation unit 12 to the predicted tide level obtained by the tide level prediction unit 13 In addition unit 14 for obtaining predicted sea level position data (including tide level and wave components) by adding (sea surface displacement), predicted sea level position data obtained by this addition unit 14 and the above RTK calculation unit 11 The data selection unit 15 that inputs the obtained actual sea level position data (hereinafter also referred to as actual sea level position data) and outputs either one of the sea level position data, and the sea level position obtained by the RTK calculation unit 11 The data and the wave component obtained by the PVD calculation unit 12 are inputted to obtain a subtraction value (corresponding to the tide level) which is the difference between the two and the subtraction value is inputted. From the data selection unit 15, an abnormality determination unit (also referred to as an abnormality detection unit) 16 that determines (detects) whether or not the sea surface position data obtained by the RTK calculation unit 11 based on this subtraction value is abnormal. The data analysis unit 17 that inputs the output sea level position data and analyzes the sea level displacement to extract each component of wave, tide level, and tsunami, and the data extracted by the data analysis unit 17 are displayed on a screen, for example. And a display device 18 (specifically, it may be a monitor and may be a printer).

  In the tide level prediction unit 13, as described above, a coefficient of a quadratic polynomial having a time as a tide level prediction expression as a variable is determined by using sea surface position data for a past predetermined time (for example, about several tens of minutes). At the same time, by substituting the previous time into this tide level prediction formula, for example, the tide level up to several seconds ahead is predicted at intervals of 1 second.

  The abnormality determination unit 16 inputs the sea surface position data obtained by the RTK calculation unit 11 and the wave component obtained by the PVD calculation unit 12, and a subtraction value (corresponding to a tide level) that is the difference between the two. And a determination unit 22 that inputs the subtraction value obtained by the subtraction unit 21 and determines whether or not the sea surface position data is abnormal (abnormal positioning data). .

  In this determination unit 22, a subtraction value approximation formula (also referred to as a regression equation or a tide level approximation formula) representing a trend of subtraction values in the past several tens of minutes (tens before the current time), that is, a tide level in the tide level prediction unit 13. Similar to the prediction formula, a second-order polynomial (of course, may be first-order, third-order or higher, but the second-order polynomial is optimal) is determined by a large number (a plurality of) subtraction values, and the subtraction value that is the second-order polynomial When the difference (deviation) between the predicted subtraction value predicted using the approximate expression and the current subtraction value exceeds a predetermined set value (threshold value), it is determined that an abnormality (abnormal value) has occurred. . In other words, when the set value is exceeded, the sea level position data causes an error in determining the integer ambiguity in the RTK calculation due to some cause, for example, ionospheric delay, tropospheric delay, etc., and jumps to the data (jumping phenomenon) Has occurred and is determined to be abnormal.

  Also, instead of the above determination method, the time change rate (differential value) of the subtraction value is obtained, and when this time change rate is larger than a predetermined set value (threshold value), it is determined that an abnormality has occurred. May be.

  Therefore, the determination unit 22 receives a plurality of subtraction values for a predetermined time and determines an approximate expression approximate expression (more precisely, a coefficient of a quadratic polynomial), and this approximate expression determination section. The subtraction value prediction unit 32 that predicts the previous subtraction value using the subtraction value approximation formula determined in 31, the predicted subtraction value obtained by the subtraction value prediction unit 32, and the actual value obtained from the current measurement data A deviation calculating unit 33 for obtaining a difference (deviation) from the subtracted value and a difference obtained by the deviation calculating unit 33 are input and compared with a predetermined set value (threshold value), and the sea surface position data is an abnormal value. And a comparison unit 34 for determining whether or not.

  When the abnormality determination unit 16 determines that there is an abnormality, the tide level prediction formula used in the tide level prediction unit 13 is not updated. That is, the predicted tide level is obtained without updating the coefficient of the second order polynomial. If it is determined that there is an abnormality, the abnormality determination unit 16 outputs the determination result to the data selection unit 15, and the data selection unit 15 predicts the prediction obtained by the addition unit 14. The sea level position data is output to the data analysis unit 17.

  On the other hand, when the abnormality determination unit 16 determines that the abnormality is not abnormal, that is, is normal, the determination result is not output. Therefore, even in this case, the tide level prediction unit 13 obtains the predicted tide level and sends it to the data selection unit 15, but in the data selection unit 15, the actual sea level position data obtained by the RTK calculation unit 11 is the data. The data is output to the analysis unit 17.

Here, the PVD calculation unit 12 will be described.
The PVD calculation unit 12 performs GPS reception based on the amount of variation applied by applying an appropriate bandpass filter to carrier phase distance data from three or more GPS satellites, and the azimuth and elevation angles of each GPS satellite. Fluctuation in 3D coordinates of GPS receiver (corresponding to observation station) by creating three or more linear equations with unknown 3D coordinates of the aircraft and solving this ternary linear simultaneous equation A component amount (displacement), that is, a sea surface displacement (X, Y, Z) which is a wave component is obtained.

More specifically, the fluctuation amount P _n obtained from the carrier wave from the GPS satellite with the number _n is represented by the following equation (1) using the three-dimensional coordinate components (x, y, z). Is done.
P _n = a _n x + b _n y + c _n z (1)
In the above formula (1),

であり、Ａｚ_ｎおよびＥｌ_ｎは、ｎ番目のＧＰＳ衛星の方位角および仰角である。したがって、３個以上のＧＰＳ衛星（ｎ＝１，２，３，・・・）により、下記（２）式に示す三元１次連立方程式が得られ、この連立方程式を解くことにより、観測局の変位（Ｘ，Ｙ，Ｚ）を求めることができる。

Az _n and El _n are the azimuth and elevation angles of the nth GPS satellite. Therefore, the ternary linear simultaneous equation shown in the following equation (2) is obtained by three or more GPS satellites (n = 1, 2, 3,...), And by solving these simultaneous equations, the observation station Displacement (X, Y, Z) can be obtained.

ところで、上記フィルタ適用済みの変動量は、ＧＰＳ受信機により計測された搬送波位相距離データに対して、風波の周波数帯域分のみを通過させるバンドパスフィルタを適用することにより得られる。

By the way, the fluctuation amount after the filter application is obtained by applying a band-pass filter that passes only the frequency band of the wind wave to the carrier phase distance data measured by the GPS receiver.

Next, the data analysis unit 17 will be described.
The data analysis unit 17 receives the sea surface position data selected by the data selection unit 15 and extracts a wave extraction unit 41 for extracting waves, a tide level extraction unit 42 for extracting tide levels, and a tsunami extraction for extracting tsunamis. Part 43.

In the wave extraction unit 41, the sea surface position data is subjected to a high-pass filter (for example, an FIR filter is used), and only the wave component that is a short period component is extracted.
Further, in the tide level extraction unit 42, low-pass filter processing is performed on the sea surface position data, and short-period components such as wave components are removed to extract tide levels that are long-period components (the tsunami component remains). ). As this low-pass filter, an FIR type is used (the calculation method corresponds to a weighted moving average), and short-period components can be removed without distorting the waveform. 3A and 3B show the impulse response and amplitude response of the low-pass filter used.

  Further, as shown in FIG. 4, the tsunami extraction unit 43 performs FIR-type low-pass filter processing on the sea surface position data, removes short-period components such as wave components, and the actual tide level (hereinafter actually measured). The measured tide level detecting unit 51 for obtaining the tide level), the tide level estimating unit 52 for estimating the tide level using the tide level estimation formula, and the estimated tide level obtained by the measured tide level detecting unit 51 and the estimation obtained by the tide level estimating unit 52 A tsunami detection unit 53 is provided for detecting a tsunami by inputting a tide level and subtracting the estimated tide level from the measured tide level. That is, by subtracting the estimated tide level from the measured tide level, it is possible to extract a tsunami component having a longer period than the wave.

Here, the tide level estimation formula provided in the tide level estimation unit 52 will be described.
The tide height η at a certain point (λ, ψ) on the earth is generally expressed by the following equation (3).

但し、（３）式中、ｉは分潮の番号（実用上の分潮個数を示す、例えば４〜１６が用いられる）、Ａ_ｉ（λ，ψ）は振幅、ω_ｉは角周波数（２π／Ｔ_ｉ：Ｔ_ｉは分潮の周期）、θ_ｉ（λ，ψ）は位相（遅角）を示す。

However, in the formula (3), i is a tide number (indicating a practical tide number, for example, 4 to 16 is used), A _i (λ, ψ) is an amplitude, ω _i is an angular frequency (2π / T _i : T _i is the period of the tidal current) and θ _i (λ, ψ) is the phase (retard angle).

When a _i = A _i (λ, φ) · cos θ _i (λ, φ) and b _i = A _i (λ, φ) · sin θ _i (λ, φ), the above equation (3) is expressed by the following equation (4): It is expressed as an equation.

ところで、分潮の周波数ω_ｉは既知であり、したがって上記（４）式の左辺に過去の実測海面位置データを代入し最小二乗法を用いることにより、ａ_ｉおよびｂ_ｉを求めれば、下記（５）式により振幅および位相を求めることができる。

By the way, the frequency ω _i of the tide is already known. Therefore, if a _i and b _i are obtained by substituting the past measured sea surface position data into the left side of the above equation (4) and using the least square method, the following ( 5) The amplitude and phase can be obtained from the equation.

この（５）式で求められたＡ_ｉ（λ，ψ）およびθ_ｉ（λ，ψ）を用いれば、任意の観測時刻における潮位を推定することができる。つまり、波浪成分および津波成分が除去された潮位を求めることができる。したがって、実測海面位置データから推定潮位を減算すれば、津波成分を求めることができる。

By using A _i (λ, ψ) and θ _i (λ, ψ) obtained by the equation (5), the tide level at an arbitrary observation time can be estimated. That is, the tide level from which the wave component and the tsunami component are removed can be obtained. Therefore, the tsunami component can be obtained by subtracting the estimated tide level from the measured sea level position data.

Hereinafter, the sea level displacement measuring method in the sea level displacement measuring apparatus mentioned above is demonstrated.
The measurement data is acquired from the reference station 1 and the observation station 2, and the sea surface position data is obtained by the RTK operation unit 11, and the sea surface displacement amount, that is, the wave component, is obtained by the PVD operation unit 12, respectively.

  Then, the sea surface position data and the wave component are input to the abnormality determination unit 16, and it is determined whether or not the sea surface position data is an abnormal value. That is, the sea surface position data and the wave component are input to the subtraction unit 21 to obtain a subtraction value that is a difference, and the approximate expression determination unit 31 of the determination unit 22 predicts a subtraction value based on the past sub-tenth subtraction value. After the equation is determined (that is, the coefficient of the second-order polynomial is determined), the subtraction value prediction unit 32 obtains the predicted subtraction value based on the subtraction value prediction formula, and then the deviation calculation unit 33 predicts the subtraction value. And a difference (deviation) from the actual subtraction value obtained from the actual measurement data is obtained, and this difference is input to the comparison unit 34 and compared with a predetermined set value.

  For example, when the difference between the subtraction values is less than or equal to the set value, it is determined that no jump has occurred in the sea surface position data and is normal. In this case, no special instruction is sent to the data selection unit 15, and therefore the actual sea level position data obtained by the RTK calculation unit 11 is output to the data analysis unit 17 as it is.

  On the other hand, if the difference between the subtraction values exceeds the set value, a jump has occurred in the sea surface position data due to some cause, for example, ionospheric delay, tropospheric delay, etc., and it is determined to be abnormal.

  Then, if it is determined that the sea level position data is abnormal, the determination result is input to the tide level prediction unit 13 and the tide level prediction formula is not updated, that is, the predicted tide level based on the tide level prediction formula used so far. Is required. The update is not performed until there is no abnormality.

  The predicted sea level position data obtained by adding the wave component obtained by the predicted tide level and the PVD calculation unit 12 by the adding unit 14 is sent to the data selection unit 15, and the predicted sea level position data is converted into the data analysis unit. 17 is output.

  In the data analysis unit 17, waves and tide levels are extracted in each extraction unit. Of course, the tsunami is also extracted by the tsunami extraction unit 43. However, when it is determined that the tsunami is abnormal, the tsunami component that is a long-period component is removed when the wave component is extracted by the PVD method. Tsunamis are not extracted because the predicted tide level is used as position data (however, tsunamis cannot be detected when the sea surface position data is abnormal, but the tsunami cycle is longer than the duration of the abnormal state of the data) In some cases, the tsunami can be detected after recovery from the abnormal state).

The wave, tide level, and tsunami data extracted by the data analysis unit 17 are sent to the display device 18 and displayed on a screen or the like.
FIG. 5 shows a waveform diagram of data. (A) shows sea surface position data (GPS positioning altitude), (b) shows wave data, (c) shows tide level data, and (d) shows tsunami data (tsunami does not appear in this waveform).

  In this way, when there is an abnormality such as a jump in the sea surface position data due to disturbances such as ionospheric delay or tropospheric delay, the presence / absence of abnormality is determined using the sea surface position data by the RTK method and the wave component by the PVD method. In addition, since the predicted sea level position data is used instead of the actually measured sea level position data as the data to be input to the data analysis unit when it is determined to be abnormal, the data extracted by the data analysis unit has an abnormality. Not detected. That is, it is possible to prevent an abnormal jump from being erroneously detected as a tsunami.

  More specifically, the PVD method is a GPS positioning method that can measure the displacement of a measurement object with the same accuracy as the RTK method, although it is a single positioning. For example, when a high-pass filter is used, the cutoff frequency is increased. The long-period components affected by the ionospheric delay, the tropospheric delay, and the like are removed, and only the wave component that is a short-period component is extracted.

  Therefore, if the wave component by the PVD method is subtracted from the sea surface position data measured by the RTK method, an integer value ambiguity determination error occurs during the RTK method calculation, and a jump (jumping phenomenon) occurs in the sea surface position data. In this case, since the sea surface position data predicted based on the past sea surface position data is output to the data analysis unit, it is prevented from erroneously reporting that it is a tsunami. can do.

  In the RTK method, the main cause of the jump in data is that a long-cycle error component due to ionospheric delay or tropospheric delay is superimposed on the carrier phase. On the other hand, in the PVD method, since these long-period error components are removed by filtering (for example, high-pass filtering), no jump occurs in the measurement data by the PVD method.

  By the way, since the sea level position data of the reference station obtained by the RTK method includes a wave component, it is impossible to detect an abnormal value without performing any signal processing. However, by removing a wave component by applying a general low-pass filter to the RTK raw data, the presence or absence of fluctuation can be confirmed, but the fluctuation component (subtraction value) itself is smoothed. If a certain amount of time has not passed, it cannot be determined as an abnormal value. To make it easier to understand, even if there is an instant jump, if the front and back of this part are smoothed (averaged), the change curve will have a certain inclination angle. Cannot determine the presence or absence of. Therefore, the abnormal value cannot be detected in real time.

  On the other hand, in the first embodiment, the deviation of data by two real-time observation methods (RTK method and PVD method) is taken, and the fluctuation component (the source calculation value) is not smoothed. Therefore, the abnormal value can be detected instantaneously without time delay. In addition, when an abnormality occurs in the measurement data by the RTK method, the measurement data by the PVD method can be supplemented by using the measurement data, so that an improvement in the measurement rate of the observation data is expected.

Here, the sea level displacement measuring method according to the first embodiment is described in the step format as follows.
In other words, this sea level displacement measurement method includes measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver installed on an observation buoy moored in a predetermined sea area. A first calculation step for obtaining sea surface position data by a real-time kinematic method using measurement data obtained by (hereinafter referred to as an observation station);
A second calculation step for obtaining sea level displacement as a wave component by a high-precision fluctuation detection method that inputs observation measurement data from an observation station and obtains a fluctuation component using a single positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is an abnormality in the abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. This is a method for outputting the predicted sea level position data.
[Embodiment 2]
Next, a GPS displacement measurement device and displacement measurement method [sea surface displacement measurement device (sea surface displacement measurement system) and sea surface displacement measurement method using GPS] with RTK abnormality positioning data processing according to Embodiment 2 of the present invention are shown in FIG. 6 will be described.

  In the first embodiment described above, it has been described that whether or not an abnormality has occurred in the sea surface position data using the wave component of the sea surface position data obtained by the PVD method, but the present second embodiment. In the method, a wave component (wave data) is obtained by using a precise fluctuation measuring method [hereinafter referred to as KVD (Kinematics for precise Variance Detection) method (see JP 2001-281323 A)].

  The difference between the configuration of the second embodiment and the configuration of the first embodiment is that the KVD calculation unit is used in place of the PVD calculation unit, and therefore the other structural members are almost the same. Since they are the same, the same constituent members will be described using the member numbers given in the first embodiment while paying attention to the different portions.

Hereinafter, this sea level displacement measuring apparatus will be schematically described.
That is, this sea level displacement measuring device receives the reference measurement data from the reference station 1 and the observation measurement data from the observation station, and obtains the sea level position data of the observation station by the real-time kinematic method (first calculation unit). ) 11 and the reference measurement data from the reference station 1 and the observation measurement data from the observation station 2 are input, and the fluctuation component, that is, the wave component (short-period component) is obtained by the precise fluctuation detection method that obtains the fluctuation component using the relative positioning method. The KVD calculation unit (second calculation unit) 12 ′ for obtaining the sea level displacement amount and the sea level position data obtained by the RTK calculation unit 11 are input and determined based on the past sea level position data and the passage of time. The tide level prediction unit 13 that predicts the tide level using the tide level prediction formula that is updated together with the predicted tide level obtained by the tide level prediction unit 13 includes the KVD The addition unit 14 for adding the sea level displacement obtained by the calculation unit 12 ′, the predicted sea level position data obtained by the addition unit 14, and the actual sea level position data obtained by the RTK calculation unit 11 are input. At the same time, the data selection unit 15 for outputting either one of the sea level position data, the actual sea level position data obtained by the RTK calculation unit 11 and the sea level displacement obtained by the KVD calculation unit 12 ′ are input. In addition, the subtraction value which is the difference between the two is obtained, and whether or not the sea surface position data obtained by the RTK calculation unit 11 based on these many (plural) subtraction values [or the rate of change of time (differential value)] is abnormal. The tide level prediction formula used in the tide level prediction unit 13 is updated when the abnormality determination unit 16 determines that there is an abnormality. It has been in strange. That is, when the predicted tide level is obtained without updating the coefficient of the quadratic polynomial, and when it is determined to be abnormal, the determination result is output from the abnormality determination unit 16 to the data selection unit 15 and the addition is performed. The predicted sea surface position data obtained by the unit 14 is output.

Here, the KVD method will be generally described.
In this KVD method, a relative vector (relative displacement) between a reference GPS receiver (which is a reference station) and an observation GPS receiver (which is an observation station) placed on an object is a long-period fluctuation component which does not depend on the fluctuation of the object. And the short-period fluctuation component depending on the fluctuation of the object, and the short-period fluctuation component is represented by each x, y, z-axis component of the unit vector from the reference GPS receiver to the GPS satellite, and at least three The carrier phase between each GPS satellite and each GPS receiver is measured, and this measurement data is passed through a bandpass filter to extract a short-period phase component corresponding to a short-period fluctuation component of the relative vector. Regarding the periodic phase component, at least three single differences between the receivers between each GPS receiver and each GPS satellite are obtained, and based on the at least three single differences between the receivers. A method for measuring the displacement of the object each axis component of the short-period fluctuation component of the relative vector obtained by calculation.

Hereinafter, a detailed description will be given.
First, the relative vector (also referred to as relative position vector or relative displacement vector) Δ * r shown in the following equation (6) between the reference GPS receiver and the observation GPS receiver: * (However, in the formula, it is shown in bold. The same applies hereinafter.) As shown in the following formulas (7) and (8): Long-period fluctuation component Δ * rL that does not depend on fluctuations (indicated by a symbol of L for a long period, and in the formulas, it is indicated by a symbol of a hat. The same shall apply hereinafter) and short-period fluctuations that depend on the fluctuation of an object It is divided into components Δ * rS (indicated by a symbol of S for a short period, and in the formulas are represented by symbols of waves of ˜. The same shall apply hereinafter.) When each component is displayed, the following formula (9) is obtained. Become. In the equations, x, y, and z indicate the x, y, and z coordinates in the geodetic coordinate system, the subscript number 1 indicates the observation GPS receiver, and the number 0 indicates the reference GPS receiver.

上記（９）式を距離ρについての受信機間一重差を求める下記（１０）式に代入すると、下記（１１）式が得られる。

Substituting the above equation (9) into the following equation (10) for obtaining the single difference between the receivers for the distance ρ, the following equation (11) is obtained.

（Δρ）_０１ ^ｉの短周期変動成分を（ΔρＳ）_０１ ^ｉ（ｔ）とすると下記（１２）式が求められる。

If the short period fluctuation component of (Δρ) ₀₁ ⁱ is (ΔρS) ₀₁ ⁱ (t), the following equation (12) is obtained.

ところで、衛星に起因する誤差が少ない場合には，搬送波位相の受信機間一重差（Δφ）_０１ ^ｉの短周期変動成分である短周期位相成分を（ΔφＳ）_０１ ^ｉ（ｔ）とすると、（ΔＮ）_０１ ^ｉは時間的に変動しない（Ｎは整数値アンビギュイティを示す）、すなわち物体の変動に依存しない長周期変動成分であるので、下記（１３）式が成立する。

By the way, when the error due to the satellite is small, if the short-period phase component that is the short-period fluctuation component of the single phase difference (Δφ) ₀₁ ⁱ between the carrier phases is (ΔφS) ₀₁ ⁱ (t), ΔN) ₀₁ ⁱ does not vary with time (N represents an integer value ambiguity), that is, is a long-period variation component that does not depend on the variation of the object, so the following equation (13) is established.

したがって、３個以上の衛星情報から３個以上の短周期位相成分（ΔφＳ）_０１ ^ｉ（ｔ）が得られれば，３個の（１２）式を得ることができ、従って相対ベクトルの短周期変動成分ΔｒＳ（ｔ）＝（ΔｘＳ_０１ ^ｉ（ｔ），ΔｙＳ_０１ ^ｉ（ｔ），ΔｚＳ_０１ ^ｉ（ｔ））を決定することができる。

Therefore, if three or more short-period phase components (ΔφS) ₀₁ ⁱ (t) are obtained from three or more satellite information, three (12) equations can be obtained, and accordingly, the short-period fluctuation of the relative vector The components ΔrS (t) = (ΔxS ₀₁ ⁱ (t), ΔyS ₀₁ ⁱ (t), ΔzS ₀₁ ⁱ (t)) can be determined.

The time-varying component of the carrier wave phase φ, that is, the short-period phase component φS _α ⁱ (t); (α = 0, 1) that depends on the fluctuation of the object is given to the raw observation value φ _α ⁱ by a predetermined value. It can be obtained by applying a band pass filter.

That is, the displacement of the object provided with the observation receiver can be measured based on the short-period phase component φS that is the time-varying component of the carrier wave phase that has passed through the bandpass filter.
Since the sea surface displacement measuring method is the same as that described in the first embodiment, the description thereof is omitted.

  The difference from the first embodiment described above is that only the KVD calculation unit is used instead of the PVD calculation unit, and the data obtained by both calculation units is the same wave component data. The same effects as those according to the first embodiment can be obtained.

  In other words, according to the sea level displacement measuring apparatus and the sea level displacement measuring method according to the second embodiment, the waves obtained by the PVD method by the single positioning method or the KVD method by the relative positioning method with respect to the sea surface position data obtained by the RTK method. When subtracting the component, it is determined whether there is an abnormality (abnormal positioning data) such as a jump in the sea surface position data based on the subtraction value or the time change rate (differential value) of the subtraction value. Since the data output when it is determined to be normal predicted sea surface position data obtained by adding a wave component to the tide level obtained from the tide level prediction unit, no abnormality is detected in the data. Therefore, when the tsunami is monitored, the abnormal data is not erroneously detected as a tsunami, so that the tsunami warning can be prevented from being erroneously issued.

Here, when the sea level displacement measuring method according to the second embodiment is described in a step format, it is as follows.
In other words, this sea level displacement measurement method includes measurement data obtained by a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver installed on an observation buoy moored in a predetermined sea area. A first calculation step for obtaining sea surface position data by a real-time kinematic method using measurement data obtained by (hereinafter referred to as an observation station);
A second calculation step for obtaining sea level displacement, which is a wave component, by inputting a reference measurement data from a reference station and an observation measurement data from an observation station and obtaining a fluctuation component using a relative positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is an abnormality in the abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. This is a method for outputting the predicted sea level position data.

It is a block diagram which shows schematic structure of the displacement measuring device which concerns on Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the judgment part in the abnormality judgment part of the displacement measuring device. It is a characteristic view of the low pass filter used in the tide level extraction part of the same displacement measuring device, (a) shows an impulse response, (b) shows an amplitude response. It is a block diagram which shows schematic structure of the tsunami extraction part in the data analysis part of the displacement measuring device. It is a figure of the waveform data measured or extracted by the same displacement measuring device, (a) is the sea surface position data obtained by the RTK method, (b) is the wave, (c) is the tide level, (d) is the tsunami . It is a block diagram which shows schematic structure of the displacement measuring device which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reference GPS receiver 2 Observation GPS receiver 11 RTK calculating part 12 PVD calculating part 12 'KVD calculating part 13 Tidal level prediction part 14 Adder part 15 Data selection part 16 Abnormality judgment part 17 Data selection part 21 Subtraction part 22 Determination part 41 Tsunami Extraction unit 42 Tidal level extraction unit 43 Tsunami extraction unit 51 Measured tide level detection unit 52 Tidal level estimation unit 53 Tsunami detection unit

Claims (4)

Measurement data obtained with a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver (hereinafter referred to as an observation station) installed on an observation buoy moored in a predetermined sea area A device for measuring sea surface displacement based on the obtained measurement data,
A first calculation unit that inputs reference measurement data from the reference station and observation measurement data from the observation station and obtains sea level data of the observation station by a real-time kinematic method (RTK);
A second computing unit that obtains sea surface displacement as a wave component by a high-precision fluctuation detection method that inputs observation measurement data from an observation station and obtains a fluctuation component using a single positioning method;
A tide level prediction unit that inputs sea level position data obtained by the first calculation unit and predicts a tide level using a tide level prediction formula that is determined based on past sea level position data and updated over time;
An addition unit for obtaining predicted sea level position data by adding the sea level displacement obtained by the second calculation unit to the predicted tide level obtained by the tide level prediction unit;
A data selection unit that inputs the predicted sea surface position data obtained by the addition unit and the sea surface position data obtained by actual measurement obtained by the first calculation unit and outputs any one of the sea surface position data;
The actual sea level position data obtained by the first computing unit and the sea level displacement obtained by the second computing unit are input to obtain a subtraction value which is the difference between the two and the subtraction value or the differential of the subtraction value An abnormality determination unit that determines whether or not the sea level position data obtained by the first calculation unit based on the value is abnormal,
In addition, when the abnormality determination unit determines that the data is abnormal positioning data, the tide level prediction formula is not updated when the predicted tide level is calculated by the tide level prediction unit, and the determination result is used as the above data. A displacement measuring device using GPS, which is configured to output the predicted sea surface position data obtained by the adding unit to the selecting unit. Measurement data obtained with a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver (hereinafter referred to as an observation station) installed on an observation buoy moored in a predetermined sea area A first calculation step for obtaining sea surface position data by real-time kinematic method (RTK) using the obtained measurement data;
A second calculation step for obtaining sea level displacement as a wave component by a high-precision fluctuation detection method that inputs observation measurement data from an observation station and obtains a fluctuation component using a single positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is abnormal positioning data in this abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. A displacement measurement method using GPS, wherein the predicted sea surface position data obtained in step 1 is output. Measurement data obtained with a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver (hereinafter referred to as an observation station) installed on an observation buoy moored in a predetermined sea area A device for measuring sea surface displacement based on the obtained measurement data,
A first calculation unit that inputs reference measurement data from the reference station and observation measurement data from the observation station and obtains sea level data of the observation station by a real-time kinematic method (RTK);
A second calculation unit that inputs the reference measurement data from the reference station and the observation measurement data from the observation station, and obtains the sea surface displacement that is a wave component by a precise fluctuation detection method that obtains the fluctuation component using a relative positioning method;
A tide level prediction unit that inputs sea level position data obtained by the first calculation unit and predicts a tide level using a tide level prediction formula that is determined based on past sea level position data and updated over time;
An addition unit for obtaining predicted sea level position data by adding the sea level displacement obtained by the second calculation unit to the predicted tide level obtained by the tide level prediction unit;
A data selection unit that inputs the predicted sea surface position data obtained by the addition unit and the sea surface position data obtained by actual measurement obtained by the first calculation unit and outputs any one of the sea surface position data;
The actual sea level position data obtained by the first computing unit and the sea level displacement obtained by the second computing unit are input to obtain a subtraction value which is the difference between the two and the subtraction value or the differential of the subtraction value An abnormality determination unit that determines whether or not the sea level position data obtained by the first calculation unit based on the value is abnormal,
In addition, when the abnormality determination unit determines that the data is abnormal positioning data, the tide level prediction formula is not updated when the predicted tide level is calculated by the tide level prediction unit, and the determination result is used as the above data. A displacement measuring device using GPS, which is configured to output the predicted sea surface position data obtained by the adding unit to the selecting unit. Measurement data obtained with a reference GPS receiver (hereinafter referred to as a reference station) installed on the ground and an observation GPS receiver (hereinafter referred to as an observation station) installed on an observation buoy moored in a predetermined sea area A first calculation step for obtaining sea surface position data by real-time kinematic method (RTK) using the obtained measurement data;
A second calculation step for obtaining sea level displacement, which is a wave component, by inputting a reference measurement data from a reference station and an observation measurement data from an observation station and obtaining a fluctuation component using a relative positioning method;
A tide level prediction step of inputting the sea level position data obtained in the first calculation step and predicting a tide level using a tide level prediction formula determined based on past sea level position data and updated over time;
An addition step for obtaining predicted sea level position data by adding the sea level displacement obtained in the second calculation step to the predicted tide level obtained in the tide level prediction step;
A data selection step for inputting the predicted sea surface position data obtained in the addition step and the actually measured sea surface position data obtained in the first calculation step and outputting any one of the sea surface position data;
The actual sea level position data obtained in the first computation step and the sea surface displacement obtained in the second computation step are input to obtain a subtraction value which is the difference between them, and the subtraction value or the differential value of the subtraction value is obtained. An abnormality determination step for determining whether or not the sea surface position data obtained in the first calculation step is abnormal,
In addition, when it is determined that there is abnormal positioning data in this abnormality determination step, the tide level prediction formula is not updated when the predicted tide level is obtained in the tide level prediction step, and the addition step is performed in the data selection step. A displacement measurement method using GPS, wherein the predicted sea surface position data obtained in step 1 is output.

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