JPH0815405A - Aircraft-position evaluating system in landing guidance - Google Patents

Abstract

PURPOSE:To provide an aircraft-position evaluating system in landing control which is not dependent on a GPS. CONSTITUTION:Three ground stations 2 to 4, which are arranged at the different positions around a runway, 1 and a geostationally satellite 5 are four signal sources when the three-dimensional position of an aircraft 7 is evaluated. The geostationally satellite transmits the pseudo-GPS signal under the control of a ground control facility 6. Three ground stations also transmits the pseudo-GPS signals. In the pseudo-GPS signal, the code, which is not used in the actual GPS signal, is used among the codes contained in the GPS. Each transmitting station transmits the mutually different pseudo-GPS signal in the time synchronized pattern with the GPS signal. The aircraft can receive both signals. A ground monitoring station 8 monitors the pseudo-GPS signals, stops the transmission when the signal deviated from the specified accuracy is detected and stops the use of the pseudo-GPS signal of the aircraft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aircraft position locating system for landing guidance.

[0002]

As is well known, a global positioning system (GP) using satellites is known.
S) is a system under the control of the US military,
Since some of the codes held as are open to the private sector, various landing guidance systems using this GPS have been conventionally proposed (for example, Japanese Patent Laid-Open No. 2-6).
No. 0897, JP-A-2-287900, etc.).

The aircraft position locating system for landing guidance that has been conventionally proposed is, for example, as shown in FIG.
As shown in, a GPS receiver that receives GPS signals from a plurality of GPS satellites 21 belonging to GPS is mounted on the aircraft 22, and the three-dimensional position of the aircraft is obtained from the received GPS signals in the aircraft 22, and based on that, It is a system that enters the runway 23.

[0004]

By the way, in the aircraft position evaluation system in the landing guidance, when the accuracy of the navigation system deteriorates to the extent of exceeding the allowable value, a function of immediately notifying the user of the navigation system ( This function is called "integrity") and this function is required to be less than 1 second. However, since the GPS is under the control of the US military and the private users are in a position of silently accepting its use, the US military has no obligation to notify the private users of the deterioration in accuracy. Therefore, in the past, if there was a deterioration in accuracy, civilian users would contact the US military, and as a result, the time from accuracy deterioration to notification would be 1
Since it takes about 0 minutes to several hours, incomplete integrity is a problem.

Further, recently, intentional deterioration of accuracy has come to be performed due to political reasons, which is a problem. This is called SA (Selective Availability), but it interferes with the use of GPS signals for military purposes by unfriendly countries, so the users of civil codes that are open to the public deteriorated from the original accuracy of GPS. It is intended to be used only with positioning accuracy. Specifically, GP
The operation to add an error to the S signal is performed.

Further, when GPS is used, accuracy deterioration due to radio wave propagation delay in the ionosphere and the atmosphere, GPS
There is a problem that there is a deterioration in accuracy due to errors in the satellite orbit information.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide an aircraft position locating system in landing guidance which does not require use of GPS or is a secondary use if used. To do.

[0008]

In order to achieve the above object, the aircraft position evaluation system for landing guidance according to the present invention has the following configuration. That is, the aircraft position evaluation system for landing guidance according to the first aspect of the present invention includes at least three ground stations that are located at different positions around the runway and that transmit positioning signals to the space around the runway; one geostationary satellite; An operation ground facility for transmitting positioning signals from geostationary satellites; and the aircraft receives different positioning signals transmitted by the at least three ground stations and the one geostationary satellite to evaluate a three-dimensional position; It is characterized by that.

The aircraft position evaluation system for landing guidance according to the second aspect of the invention comprises at least four ground stations arranged at different positions around the runway and transmitting positioning signals to the space around the runway; , And receive different positioning signals transmitted by the at least four ground stations to evaluate the three-dimensional position.

Here, the positioning signal may be a pseudo GPS signal using a code held by the GPS and not used for the GPS signal actually transmitted by the GPS satellite. In this case, the transmitting station transmits the pseudo GPS signal in a time-synchronized manner with the GPS signal or including data to be time-synchronized, and the aircraft uses the GPS signal.
A receiver capable of receiving both the signal and the pseudo GPS signal should be provided. Then, in the case of using the GPS as a subsidiary, as a precaution, the pseudo GPS signal is received, the signal content is monitored, and if the reception of the pseudo GPS signal deviating from the specified accuracy is detected, all Pseudo GPS for transmitting station
A ground monitor station may be installed that outputs a signal to stop the transmission of signals and outputs a signal to the aircraft to stop using pseudo GPS signals.

[0011]

Next, the operation of the aircraft position evaluation system in the landing guidance of the present invention constructed as described above will be explained. According to the present invention, the three-dimensional position of the own aircraft on the aircraft is determined by the positioning signals transmitted by one geostationary satellite and at least three ground stations (first invention) or by the positioning signals transmitted by at least four ground stations (second invention). Let's evaluate.

Therefore, since the landing guidance of the aircraft can be performed without using GPS, the integrity is assured and the influence of SA can be avoided as compared with the case of using GPS.
In addition, the accuracy of the signal is improved as a whole because there is no problem of accuracy deterioration due to the ionosphere or the atmosphere, or accuracy deterioration due to satellite orbit information errors, depending on the ground station transmission signal.

When GPS is used as a subordinate, the measurement accuracy of the aircraft can be further improved by using GPS together, and a monitor ground station can be installed in case of emergency.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an aircraft position evaluation system for landing guidance according to an embodiment of the present invention. The system of the present invention comprises at least three ground stations (2-4) arranged at different positions around the runway 1 and transmitting positioning signals to the space around the runway, one geostationary satellite 5, and this geostationary satellite. Basically includes a geostationary satellite operation ground facility 6 for transmitting a positioning signal from the aircraft 7, and the aircraft 7 has at least three ground stations (2 to
This is a system that receives different positioning signals transmitted by 4) and one geostationary satellite, evaluates the three-dimensional position of the own aircraft, and enters the runway 1.

That is, the present invention has a system configuration equivalent to the case where GPS signals from four or more GPS satellites are received to obtain a three-dimensional position, and positioning can be performed without using GPS. is there. 1 shows four signal sources consisting of three ground stations and one geostationary satellite,
A ground station can be used instead of the geostationary satellite.

However, the measurement accuracy of the three-dimensional position has an inverse correlation with the volume of the tetrahedron having four signal sources as vertices, and therefore the volume of the tetrahedron becomes small in the case of all four ground stations. Therefore, the accuracy is inferior to the case of including one geostationary satellite, but it can be said that there is no problem because the accuracy required for the landing guidance system has various levels.

Each transmitting station including the geostationary satellite operation ground facility 6 controls the frequency of the positioning signal to be transmitted, and obtains its own position information (orbit information for a geostationary satellite), transmission time information, clock drift correction information, and the like. Send the positioning signal including
As in the case where the positioning signal is a pseudo GPS signal in FIG. 1, the system of this embodiment is a system that secondarily uses GPS.

Here, the pseudo GPS signal is a code held by the GPS and is the GPS actually transmitted by the GPS satellite.
The signal is a signal using a code that is not used. Then, each transmitting station including the geostationary satellite operation ground facility 6 has a GPS
The pseudo GPS signal is transmitted in a form that is time-synchronized with the signal or including data that is time-synchronized with the GPS signal.

In this way, the aircraft 7 is equipped with a receiver capable of receiving both GPS signals and pseudo GPS signals, but a pseudo GPS receiver is constructed by making a slight design change to the GPS receiver. There is an advantage that can also be GPS
The positioning accuracy can be improved by using the signals together.

Further, as shown in FIG. 1, the ground monitor station 8
Is installed. This ground monitor station 8 is for each pseudo GPS
When a signal is received, the signal content is monitored, and when the reception of a pseudo GPS signal that deviates from the specified accuracy is detected, a signal for stopping the transmission of the pseudo GPS signal is output to all transmitting stations, and a pseudo signal is sent to the aircraft. It outputs a signal to stop using the GPS signal. If there is a difference in the transmission time,
When an abnormality occurs in the signal strength due to transmission stop or the like, the GPS signal is promptly switched to ensure that the navigation accuracy of this system is always at a level that can be used as a landing guidance system.

[0021]

As described above, the aircraft position locating system for landing guidance of the present invention uses the positioning signals transmitted by one geostationary satellite and at least three ground stations (first invention) or at least four ground stations. (2nd invention) The aircraft is made to evaluate the three-dimensional position of the aircraft by the positioning signal transmitted by the vehicle. Therefore, it is possible to guide the landing of the aircraft without using GPS. Therefore, according to the present invention, there is an effect that the integrity is assured and the influence of SA is not necessary as compared with the case of using GPS. In addition, there is no problem of accuracy deterioration due to the ionosphere or the atmosphere, or accuracy deterioration due to satellite orbit information errors, depending on the signal transmitted by the ground station, so there is also an effect of improving accuracy as a whole. When GPS is used as a subordinate, there is an effect that the measurement accuracy can be further improved by using the GPS together with the aircraft, and a monitor ground station can be installed in case of emergency.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an aircraft position evaluation system in landing guidance according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of an aircraft position evaluation system in conventional landing guidance using GPS.

[Explanation of symbols]

 1 Runway 2 Ground station 3 Ground station 4 Ground station 5 Geostationary satellite 6 Geostationary satellite operation ground facility 7 Aircraft 8 Ground monitor station

Claims (7)

[Claims] 1. At least 3 which are arranged at different positions around the runway and which transmit a positioning signal to a space around the runway.
Two ground stations; one geostationary satellite; and an operational ground facility that transmits positioning signals from this geostationary satellite; and the aircraft has different positionings transmitted by the at least three ground stations and the one geostationary satellite. Receiving a signal to evaluate a three-dimensional position; an aircraft position evaluation system for landing guidance. 2. At least 4 which are arranged at different positions around the runway and which transmit positioning signals to the space around the runway.
Three ground stations; and the aircraft receives three different positioning signals transmitted by the at least four ground stations.
Assessing dimensional position; An aircraft position assessment system in landing guidance, characterized by: 3. The positioning signal is a pseudo GPS signal using a code held by GPS and not used for a GPS signal actually transmitted by a GPS satellite. Alternatively, the aircraft position evaluation system for landing guidance according to claim 2. 4. The aircraft position locating system for landing guidance according to claim 3, wherein the transmitting station transmits the pseudo GPS signal in a form time-synchronized with the GPS signal. 5. The aircraft position locating system for landing guidance according to claim 3, wherein the transmitting station transmits a pseudo GPS signal including data for time synchronization with the GPS signal. 6. The aircraft positioning system for landing guidance according to claim 4, wherein the aircraft comprises a receiver capable of receiving both GPS signals and pseudo GPS signals. 7. A pseudo GPS signal is received, the content of the signal is monitored, and when the reception of the pseudo GPS signal deviating from the specified accuracy is detected, a signal for stopping the transmission of the pseudo GPS signal is output to all transmitting stations. The aircraft position locating system for landing guidance according to claim 6, further comprising: a ground monitor station that outputs a signal to the aircraft to stop using the pseudo GPS signal.