JPH10148499A - Angle of orientation detector for flying object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the error of the angle of orientation from being accumulated with time even for an object flying over a long distance. SOLUTION: A GPS receiver 24 being carried on a flying object comprises a GPS Doppler speed detecting section 44 for detecting the speed component of the flying object in the direction of a GPS satellite, i.e., the Doppler speed component, based on a data obtained from the CPS satellite and the position of the flying object. An inertial navigation equipment(INE) 22 for the flying object comprises a section 32d for detecting the direction of the GPS satellite viewed from the flying object, a section 32e for detecting the speed of the flying object in the direction of the GPS satellite, a velocity matching section 32f for estimating the error of angle of orientation using the speed of the flying object in the direction of the GPS satellite and a GPS Doppler speed, and a section 32c for correcting the angle of orientation depending on the error of angle of orientation thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying object which is launched in the air and travels a long distance, and a flying object attitude angle detection device suitable for a flying target aircraft.

[0002]

2. Description of the Related Art Generally, an inertial navigation device (INE) 12 having a configuration as shown in FIG. As shown in FIG. 8, the INE 12 mounted on the flying object has a gyro three axis 12a, an attitude angle calculator 12b,
Coordinate transformation matrix generation unit 12c, accelerometer 3-axis 12
d, NED coordinate system acceleration detector 12e, NED
Coordinate system speed detector 12f, velocity matching unit 1
2 g are provided. The NED coordinate system is
The coordinate system uses North-East-Down as a coordinate axis.

[0003] In the flying object INE12, gyro 3
An attitude angle is calculated by the attitude angle calculation unit 12b based on the angular velocity detected by the axis 12a, and a coordinate conversion matrix is generated by the coordinate conversion matrix generation unit 12c from the calculation result of the attitude angle.

The NED coordinate system acceleration detector 12e
The outputs (three-axis acceleration) from the three axes 12d of the accelerometer are converted based on the coordinate conversion matrix generated by the coordinate conversion matrix generation unit 12c, and the accelerations (A _X , A _Y ,
_AZ ) is calculated. Further, N-E-D coordinate system speed detecting section 12f the speed by integrating the converted acceleration by N-E-D coordinate system acceleration detector _{12e (V X, V Y,} V
_Z ) is calculated.

[0005] The velocity matching unit 12g has an N-
E-D coordinate system speed detector 12f speed calculated by _{(V X, V Y, V} Z) and, carried to that aircraft INS (inertial navigation system mounted on aircraft flying object (I
NS (Inertial navigation system)), the attitude angle error is estimated based on the velocities (V _Xt , V _Yt , V _Zt ) obtained from.

That is, the velocity matching unit 12
g is the attitude angle error of the INE 12 from the difference between the two velocities (V _Xt , V _Yt , V _Zt ) and (V _X , V _Y , V _Z ) based on the following equations (1) and (2). Ask.

[0007]

(Equation 1)

Here, g is a gravitational acceleration, and Δt is a matching time interval (an integrated time interval). Since the attitude angle error of the flying object causes a speed error, the attitude angle is corrected.

FIG. 9 is a diagram for explaining a factor that causes a speed error when there is an attitude angle error. When there is an attitude angle error, the component force (gx) of the gravitational acceleration g is measured as the acceleration of the horizontal component.

Therefore, the NEED coordinate system acceleration detector 1
Detected acceleration by _{2e (A X, A Y,} A Z) by integrating the determined velocity _{(V X, V Y, V} Z) , the rate at which the gravitational acceleration g force component (gx) is integrated An error occurs.

Conventionally, when a flying object is carried on an aircraft, the speeds (V _Xt , V _Yt , V _Zt ) are input from an aircraft INS (inertial navigation device) 10 mounted on the aircraft, and The speed (V
_X , _VY , and _VZ ) are subtracted from the values to determine the amount of speed error generated from the attitude angle error. The attitude angle error is calculated from the speed error amount, and the attitude angle is corrected to perform the attitude angle detection. On the other hand, after the flying object is separated from the aircraft, the flying object INE 12 calculates the attitude angle by integrating the output from the gyro three axes 12a.

[0012]

As described above, conventionally,
The flying object INE 12 detects the attitude angle based on the speed information (V _Xt , V _Yt , V _Zt ) obtained from the aircraft INS 10. Therefore, after the flying object is separated from the aircraft, the speed information from the aircraft _{INS10 (V Xt, V Yt,} V Zt) for can not be obtained, the velocity information _{(V Xt, V Yt, V} Zt) Cannot be detected based on the position angle.

For this reason, while the flying object is flying, the attitude angle is calculated based on the output from the gyro three axes 12a, but the attitude angle errors accumulate over time due to gyro drift. On the other hand, when flying over a long distance, the value of the attitude angle error increases.

The present invention has been made in view of the above circumstances, and has a posture capable of avoiding a temporal accumulation of posture angle errors even with a flying object flying a long distance. An object of the present invention is to provide an angle detection device.

[0015]

SUMMARY OF THE INVENTION The present invention comprises a GPS (Global Positioning System) receiver and a flying object inertial navigation device (INE) mounted on a flying object. The GPS receiver determines the GPS satellite position and GP based on the data transmitted from the GPS satellite.
A GPS satellite transmission data receiving means for acquiring an S satellite speed, and a G based on a frequency displacement of a radio wave transmitted from the GPS satellite.
GPS Doppler frequency detecting means for detecting PS Doppler frequency, GPS satellite position and GPS satellite speed acquired by GPS satellite transmission data receiving means, GPS Doppler frequency detected by said GPS Doppler frequency detecting means, and self-propelled vehicle GPS Doppler speed detecting means for detecting a GPS Doppler speed, which is a speed component of the flying object in the direction of the GPS satellite, based on the position of the flying object, and the inertial navigation device of the flying object outputs an output from the gyro. Attitude angle calculation means for calculating the attitude angle of the flying object based on the attitude angle calculated by the attitude angle calculation means, and speed detection for detecting the speed of the flying object based on the output from the accelerometer Means for detecting the position of the flying object based on the initial position of the flying object and the speed detected by the speed detecting means. Detecting means, detecting the direction of the GPS satellite as viewed from the flying object based on the position of the flying object detected by the position detecting means and the GPS satellite position acquired by the GPS satellite transmission data receiving means. GPS satellite direction detecting means, and detecting the speed of the flying object in the GPS satellite direction based on the direction of the GPS satellite detected by the GPS satellite direction detecting means and the speed of the flying object detected by the speed detecting means Attitude angle error using the GPS satellite direction speed detecting means, the speed of the flying object in the GPS satellite direction detected by the GPS satellite direction speed detecting means, and the GPS Doppler speed detected by the GPS Doppler speed detecting means. Velocity matching means for estimating, wherein the attitude angle calculating means comprises: And performing correction of the attitude angle, depending on the obtained posture angle error by etching means.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a posture angle detection device according to the present embodiment. As shown in FIG. 1, the attitude angle detection device according to the present embodiment includes an aircraft INS (inertial navigation device) 20 mounted on an aircraft carrying a flying object for inputting initial information, and an attitude angle detection device mounted on the flying object. And an inertial navigation device (INE) 22 and a GPS receiver 24.

The INE 22 is provided with a sensor unit 30 and a computer 32. The sensor unit 30 includes an accelerometer three-axis 30a and a gyro three-axis 30b, and the computer 32 includes a flying object position detection unit 32a, N
-ED coordinate system speed detector 32b, attitude angle calculator 32
c, functions of a GPS satellite direction detection unit 32d, a GPS satellite direction speed detection unit 32e, and a velocity matching unit 32f are provided.

The GPS receiver 24 includes a GPS satellite transmission data receiving unit 40, a GPS Doppler frequency detecting unit 42,
A PS Doppler speed detector 44 is provided. In the attitude angle detection device shown in FIG.
G received by the GPS satellite transmission data receiving unit 40
From the transmission data from the PS satellite, the position of the GPS satellite (G
PS satellite position 40a) and the speed of the GPS satellite (GPS
Obtain the satellite speed 40b).

The GPS Doppler frequency detector 42 reads the frequency displacement (GPS Doppler frequency) of radio waves transmitted from GPS satellites. The GPS Doppler speed detector 44 detects the GPS Doppler frequency read by the GPS Doppler frequency detector 42 and
GP received by the PS satellite transmission data receiving unit 40
Based on the S satellite speed, the approach speed between the GPS satellite and the flying object is calculated, and the speed component of the flying object in the direction of the GPS satellite (by detecting the GPS Doppler speed, Output to INE22.

The INE 22 uses the output of the three-axis accelerometer 30a of the sensor unit 30 provided in the INE 22 to perform N-E-D
The speed of the flying object is detected by the coordinate system speed detection unit 32b, and the flight is performed based on the speed of the flying object detected by the NED coordinate system speed detection unit 32b and the initial position obtained from the aircraft INS20. The position of the flying object is detected by the body position detector 32a. However, when the flying object is carried on an aircraft, the aircraft INS position obtained from the aircraft INS20 is defined as the flying object position.

Further, based on the GPS satellite position 40a received by the GPS satellite transmission data receiving unit 40 and the position of the projectile detected by the projectile position detecting unit 32a, a GPS satellite direction detecting unit 32d uses The direction (elevation angle, azimuth angle) of the GPS satellite as viewed from the flying object is detected.

Further, an NED coordinate system speed detector 32
The GPS based on the speed of the flying object detected by b and the direction (elevation angle, azimuth) of the GPS satellite viewed from the flying object detected by the GPS satellite direction detection unit 32d.
The satellite direction speed detector 32e detects the speed of the flying object in the GPS satellite direction.

Since the speed in the GPS satellite direction detected by the GPS satellite direction speed detection unit 32e includes a speed error generated by the attitude angle error, the GPS satellite detected by the GPS satellite direction speed detection unit 32e. The attitude angle error is calculated (velocity matching) from the speed difference between the direction speed and the GPS Doppler speed obtained by the GPS Doppler speed detector 44 of the GPS receiver 24, and the value is returned to the attitude angle calculator 32c. Have the attitude angle corrected.

The GPS Doppler velocity obtained by the INE 22 from the GPS Doppler velocity detector 44 of the GPS receiver 24 can be obtained regardless of the separation of the flying object from the aircraft, so that the velocity matching is performed even after the separation. As a result, the attitude angle can be detected, and no temporal accumulation of the attitude angle error occurs.

Next, a specific operation of the attitude angle detecting device according to the present embodiment will be described with reference to FIG.
FIG. 2 shows data handled in each unit constituting the attitude angle detecting device. Here, as shown in FIG. 3, a case where data transmitted from two GPS satellites A and B are used will be described as an example. FIG. 3 shows the GPS Doppler velocities (V _dA , V _dB ) in the directions of the GPS satellites A and B and IN.
Rate of N-E-D coordinate system having the _{E22 (V X, V Y,} V
_Z ) is a coordinate system representing the relationship, and indicates the role of symbols used in the following description in the coordinate system. Also, FIG.
FIG. 4 is a diagram for explaining a flow of processing by each unit of the posture angle detection device.

In the GPS receiver 24, the GPS Doppler frequency detector 42 detects the GPS Doppler frequencies (f _dA , f _dB ) in the directions of the GPS satellites A and B from the frequency displacement of the radio wave transmitted from the GPS satellites (FIG. 2). 4 (A1
3)).

Further, based on the transmission data from the GPS satellites received by the GPS satellite transmission data receiving unit 40, G
The GPS satellite positions 40 (longitude λ _A , latitude Λ _A , altitude h _A ) (longitude λ _B , latitude Λ _B , altitude h _B ) of the PS satellites A and B, and the GPS satellite speed 40 _b (V _GPS-A ) (V
_GPS-B ) is obtained.

The GPS Doppler speed detector 44 detects the GP
GPS satellite speed 40 from S satellite transmission data receiving unit 40
b (V _GPS-A ) (V _GPS-B ) and GPS satellite position 40
(Longitude λ _A , latitude Λ _A , altitude h _A ) (longitude λ _B , latitude Λ
_B , altitude h _B ) and the position of the flying object ((X, Y, Z) or (λ _C , Λ _C , h
_C )), the velocity component of the GPS satellites A and B in the spacecraft direction is calculated, and this velocity is used as the GPS Doppler frequency (f _dA ,
f _dB ) is subtracted from the approaching speed of the GPS satellite and the flying object, and the Doppler velocity (V _dA , V _dB ), which is the moving component of the flying object in the directions of the GPS satellites A and B, is measured (FIG. 4 (A14)). The GPS Doppler velocity (V _dA ) is calculated based on the following equation (3). G
The PS Doppler velocity (V _dB ) is calculated by the same formula.

[0029]

(Equation 2)

Α in Equation (3) (see FIG. 3) is the GPS satellite position 40 (longitude λ _A , latitude Λ _A , altitude h _A ) and the position of the flying object ((X, Y, Z) or (λ _{C, Λ C,} h
_C )). The details of the method of calculating α will be described later.

On the other hand, in the INE 22, the attitude angle calculator 32c
Thus, the posture angles (φ, θ, ψ) are calculated using the outputs (p, q, r) of the gyro three axes 30b (FIG. 4 (A1, A3)).

The NED coordinate system speed detector 32b
Generates a coordinate transformation matrix using the attitude angles (φ, θ, ψ) calculated by the gyro three axes 30b (FIG. 4 (A4)), and based on the generated coordinate transformation matrix, an accelerometer the output of the triaxial _{30a (n X, n Y,} n
_Z ) is converted to the acceleration (A _X ,
_AY , _AZ ) are calculated (FIG. 4 (A5)). Then, the calculated accelerations (A _X , A _Y , A _Z ) are integrated to obtain N−
E-D coordinate system speed of _{(V X, V Y, V} Z) is calculated (FIG. 4 (A6)).

At the same time, the flying object position detection unit 32a sets the position (λ _C , Λ _C , h _C ) of the aircraft INS 20 as an initial value (FIG. 4 (A9)) and sets the speeds (V _X , V _Y , V V).
_Z ), the position (X,
Y, Z) is obtained (FIG. 4 (A10)).

The GPS satellite direction detecting unit 32d receives the position (X, Y, Z) of the flying object calculated by the flying object position detecting unit 32a and receives the position by the GPS satellite transmission data receiving unit 40 of the GPS receiver 24. (FIG. 4 (A8)) GPS satellite position 40 (longitude λ _A , latitude Λ _A , altitude h
_A ) Using (longitude λ _B , latitude Λ _B , altitude h _B ), the GPS satellite direction viewed from the flying object, that is, the elevation angle (a,
b) and azimuths (c, d) are obtained (FIG. 4 (A1)
2)).

The elevation angle (a) and the azimuth angle (c) of the GPS satellite A are calculated based on the following equations (4) and (5). In equation (4), R is the earth radius. GP
The calculation of the elevation angle (b) and the azimuth angle (d) for the S satellite B is performed in the same manner.

[0036]

(Equation 3)

In the GPS satellite direction speed detection unit 32e, G
PS satellite direction detecting unit GPS satellite direction (elevation, azimuth) calculated by 32d by utilizing, N-E-D coordinate system speed speed of _{(V X, V Y, V} Z) from, GPS satellites A,
B direction of the flying object velocity (V _A, V _B) obtaining the (4
(A7)). The flying object speed (V _A ) is calculated based on the following equation (6). Flying object speed (V _B )
Is similarly calculated.

[0038]

(Equation 4)

The satellite's GPS satellite velocity (V _A , V _A ) calculated by the GPS satellite velocity detector 32e.
V _B ) includes a velocity error caused by an attitude angle error. The velocity matching unit 32f calculates the velocity of the flying object in the direction of the GPS satellites (V _A , V _B ) and the GP
The attitude angle error is obtained from the speed difference from the GPS Doppler speed (V _dA , V _dB ) calculated by the S Doppler speed detection unit 44 (FIG. 4 (A15)).

That is, the velocity matching section 32
f is calculated on the basis of the vertical axis (R _A, R _B) angular error (r _A, r _B) the following equation (7) around (8) to the satellite azimuth in the horizontal plane from the speed difference (FIG. 4 (A1
6)).

[0041]

(Equation 5)

Next, from these two angle errors, the following equation (9), (10), (11), and (12) show the attitude angle error (Δ
φ, Δθ), and the obtained attitude angle error (Δφ, Δ
θ) is fed back to the attitude angle calculator 32c (FIG. 4).
(A17)).

[0043]

(Equation 6)

The attitude angle calculation section 32c corrects the attitude angle based on the attitude angle error fed back from the velocity matching section 32f, and detects the attitude angle. Next, in FIG. 5, the movement vector of the GPS satellite speed required for the calculation of the GPS Doppler speed shown in FIG. 4 (FIG. 4 (A14)) and the position vector between the GPS satellite position A and the flying object position (The angle β is calculated in the same manner). First, GP
Based on the received data, the S-satellite transmission data receiving unit 40 detects the GPS satellite position based on the following equations (13) and (14) (FIG. 5 (B1)).

[0045]

(Equation 7)

The point Q is obtained immediately before (λ _A , Λ
_A , h _A ) is calculated as (λ _A0 , Λ _A0 , h _A0 ).
Further, the flying object position detection unit 32a calculates the following equation (1)
5) to detect the position of the flying object (see FIG.
2)).

[0047]

(Equation 8)

The GPS Doppler speed detection unit 44
The position vector n between the satellite movement vector m and the GPS receiver 24 (flying vehicle) is calculated from the GPS satellite position and the flying vehicle position based on the following equations (16) and (17) (FIG. 5). (B3)).

[0049]

(Equation 9)

The GPS Doppler speed detector 44
Is the angle α formed by the position vector n between the GPS satellite movement vector m and the GPS receiver 24 from the position vector n between the GPS satellite movement vector m and the GPS receiver 24 (flying object), It is calculated based on the following equations (18) and (19) (FIG. 5 (B4)).

[0051]

(Equation 10)

Next, FIG. 6 shows a procedure for calculating the attitude angle, the speed and the position of the NED coordinate system from the outputs of the accelerometer three axes 30a and the gyro three axes 30b shown in FIG. ing.

First, based on the output (gyro three-axis output (p, q, r)) from the gyro three-axis 30b (FIG. 6C
1)), the attitude angle calculation unit 32c calculates the following equation (20).
The posture angle is calculated based on (FIG. 6 (C2)).

[0054]

[Equation 11]

Using the attitude angles (φ, θ, ψ) obtained by the attitude angle calculation section 32c, the NED coordinate system speed detection section 32b uses coordinates such as the following equation (21). A conversion matrix is generated (FIG. 6 (C2)).

[0056]

(Equation 12)

The NED coordinate system speed detector 32b uses the coordinate transformation matrix obtained in FIG. 6C2 to output from the accelerometer three axes 30a (acceleration three axes (n
_X , n _Y , n _Z )) (FIG. 6 (C4)) is converted as shown in the following equation (22), and the accelerations (A _X , A _Y , A) in the NED coordinate system are converted. _Z ) (FIG. 6 (C
5)).

[0058]

(Equation 13)

The NED coordinate system speed detector 32b integrates the calculated accelerations (A _X , A _Y , A _Z ) as shown in the following equation (23), and performs NE integration. rate of -D coordinate system _{(V X, V Y, V} Z) is calculated (FIG. 6 (C
6)).

[0060]

[Equation 14]

The flying object position detecting section 32a is provided with an NE-
The speed (V) calculated by the D coordinate system speed detection unit 32b
_X , V _Y , V _Z ) are integrated as shown in the following equation (24) to determine the position (X, Y, Z) of the flying object in the NED coordinate system (FIG. 6 (C7)).

[0062]

(Equation 15)

Next, with reference to FIG. 7, the accumulation of the attitude angle error using the attitude angle detecting device according to the present invention will be described in comparison with the prior art. In the prior art, as shown in FIG. 7, when a flying object is carried on an aircraft, it is possible to reduce the attitude angle error to 0.25 deg using highly accurate speed information obtained from the aircraft INS. it can.

(Even if accurate velocity information is obtained from the aircraft, velocity matching cannot be performed accurately due to the influence of the wing vibration. Therefore, the attitude error generated regardless of the velocity error of the aircraft is set to, for example, 0.24 deg. The attitude angle error of the aircraft substantially included is set to 0.06 deg.
Therefore, (0.24 ² +0.06 ^{2) 1/2} = 0.25. After the flying object is separated from the aircraft, the attitude angle cannot be corrected because speed information from the aircraft cannot be obtained, as shown in FIG. For this reason, in the case of a flying object flying over a long distance, after being separated from the aircraft, attitude angle errors accumulate temporally due to gyro drift. As shown in FIG. 7 (b), when flying for 20 minutes, 1 °
If a gyro having an accuracy of / h is used, the attitude angle error is added by 0.33 deg.

On the other hand, when the attitude angle detecting device according to the present embodiment is used, the GPS receiver 24 (GP) can be used regardless of the separation of the flying object from the aircraft as shown in FIG.
Since the velocity matching can be continuously performed by using the GPS Doppler speed obtained from the S-Doppler speed detector 44) to correct the attitude angle, FIG.
As shown in (1), the attitude angle error does not accumulate. Therefore, even if the flying object travels a long distance, it is possible to avoid the temporal accumulation of the attitude angle error.

[0066]

As described in detail above, according to the present invention, G
Using the GPS Doppler velocity obtained using the radio waves transmitted from the PS satellites, the attitude angle (roll angle,
Since the attitude angle is calculated by detecting the (pitch angle), it is possible to avoid temporal accumulation of the attitude angle error even for a flying object flying a long distance.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a posture angle detection device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a specific operation of the posture angle detection device according to the embodiment.

FIG. 3 is a diagram illustrating a coordinate system and symbols used in the embodiment.

FIG. 4 is an exemplary view for explaining the flow of processing by each unit of the posture angle detection device according to the embodiment.

FIG. 5 is a view for explaining a procedure for calculating an angle between a movement vector of a GPS satellite and a vector in a flying object direction viewed from the GPS satellite in the embodiment.

FIG. 6 is a view for explaining a procedure for calculating a speed and a position in the INE 22 of the embodiment.

FIG. 7 is a diagram for explaining accumulation of attitude angle errors using the attitude angle detection device according to the present embodiment, in comparison with the related art.

FIG. 8 is a diagram for explaining a conventional technique.

FIG. 9 is a diagram for explaining a factor that causes a speed error when there is an attitude angle error.

[Explanation of symbols]

 Reference Signs List 20 aircraft INS (aircraft inertial navigation device) 22 INE (flying object inertial navigation device) 24 GPS receiver 30 sensor unit 30a accelerometer 3 axis 30b gyro 3 axis 32 computer 32a projectile position detection unit 32b NE- D coordinate system speed detector 32c attitude angle calculator 32d GPS satellite direction detector 32e GPS satellite direction speed detector 32f velocity matching unit 40 GPS satellite transmission data receiver 42 GPS Doppler frequency detector 44 GPS Doppler speed detector

Claims (1)

[Claims] 1. A GPS (Glob) mounted on a flying object
al Positioning System) which comprises a receiver and an inertial navigation device (INE) for a flying object, wherein the GPS receiver determines a GPS satellite position based on data transmitted from the GPS satellite. GPS satellite transmission data receiving means for acquiring a GPS satellite speed; GPS from a frequency displacement of a radio wave transmitted from the GPS satellite;
GPS Doppler frequency detecting means for detecting Doppler frequency, and GP obtained by GPS satellite transmission data receiving means
S satellite position and GPS satellite speed, GPS Doppler frequency detected by the GPS Doppler frequency detecting means,
And the GPS of the flying object based on the position of the flying object
GPS Doppler velocity detecting means for detecting a GPS Doppler velocity which is a velocity component in a satellite direction, wherein the inertial navigation device of the flying object calculates an attitude angle of the flying object based on an output from a gyro. Attitude angle calculating means; speed detecting means for detecting the speed of the flying object based on the attitude angle calculated by the attitude angle calculating means and the output from the accelerometer; initial position of the flying object and the speed Position detecting means for detecting the position of the flying object based on the speed detected by the detecting means; position of the flying object detected by the position detecting means; and GPS obtained by the GPS satellite transmission data receiving means. GPS satellite direction detecting means for detecting the direction of the GPS satellite as viewed from the flying object based on the satellite position; The GPS
GPS satellite direction speed detecting means for detecting the speed of the flying object in the GPS satellite direction based on the direction of the satellite and the speed of the flying object detected by the speed detecting means, and detecting by the GPS satellite direction speed detecting means Done G
A velocity matching means for estimating an attitude angle error using the velocity of the flying object in the direction of the PS satellite and the GPS Doppler velocity detected by the GPS Doppler velocity detection means; An attitude angle detecting device for correcting an attitude angle in accordance with an attitude angle error obtained by velocity matching means.