JPH07280917A - Method for retransmitting gps radio waves to gps-radio-wave unreceivable space - Google Patents

Abstract

PURPOSE:To obtain a retransmission method in which GPS radio waves can be received even in a radio-wave unreceivable space, in which own position can be confirmed quickly after they have gone out from the radio-wave unreceivable space and in which the maintenance, the inspection, the repair and the like of a GPS receiver can be performed indoors. CONSTITUTION:GPS radio waves which are sent out from GPS satellites 1 are received by an external antenna 2 which has been installed outdoors, and the received radio waves are retransmitted into a radio-wave unreceivable space 4 such as a building, a tunnel or the like from an internal antenna 5 installed inside the radio-wave unreceivable space 4 via a retransmitting device 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The method of retransmitting GPS radio waves into a GPS radio wave unreceivable space according to the present invention enables radio waves sent from GPS satellites to be received by a receiver in a place where radio waves do not reach, such as a building or a tunnel. For example, when a vehicle waiting in a garage or a vehicle traveling in a tunnel goes out to a place where GPS radio waves from GPS satellites can be directly received, the positioning state is promptly set. The present invention can be used to perform operations such as maintenance, inspection, and repair of GPS receivers even indoors where GPS radio waves do not normally reach.

[0002]

2. Description of the Related Art GPS (Global Positioning
The system is an artificial satellite (G
By using the PS satellite) and receiving the radio waves (1.575 GHz, 1.227 GHz) sent from this GPS satellite with the GPS receiver, the position of the self (position of the receiver)
This is a global positioning system that enables highly accurate positioning. In the completed GPS, as shown in FIG. 2, a total of 24 GPS satellites A are deployed in 6 circular orbits of about 20,000 km above the earth, and four GPS satellites A are always placed at any place on the earth. By being able to catch satellite A and receiving GPS radio waves from these several GPS satellites A at the same time, the receiver can confirm his or her exact position. However, at this stage, all 24 GPS satellites A have not been deployed, so satellite A that can be supplemented depending on the time of day.
In some cases, the number of is less than the number required for accurate positioning, and the positioning accuracy may drop.

The GPS radio waves transmitted from the GPS satellite A include satellite orbit information (ephemeris) and messages such as satellite calendar (almanac). The almanac is like a satellite timetable and serves as information for the GPS receiver B to determine a satellite that can be supplemented. Further, the ephemeris indicates the accurate position of the satellite A, and is important information for obtaining the distance between the GPS receiver B and the satellite A.

Further, the GPS receiver B uses the G from the satellite A.
Before starting positioning by receiving PS radio waves with the receiving antenna C, select the satellite A that can be received in that time zone based on the almanac received in the past, and then change the clock frequency of the receiver B subtly. A search operation for capturing the signal from the satellite A is performed (the frequency of the radio wave from the GPS satellite A flying at high speed increases or decreases due to the Doppler effect).
This search operation normally takes a few seconds to a few tens of seconds, but when the GPS receiver B has not been used for a long time, the received almanac is old, or if it has moved far from the previously located position. Requires a longer time because GPS receiver B automatically acquires all satellites (it takes 12 minutes and 30 seconds or more to receive all almanacs).

[0005]

The GPS is 1.2 GH
Due to the use of quasi-microwave radio waves in the z band and 1.5 GHz band and the fact that it takes a certain amount of time from when GPS receiver B receives the radio waves to when positioning is possible, There was a problem. ． Since the quasi-microwave radio waves in the 1.2 GHz band and the 1.5 GHz band have properties close to that of light, if there is an obstacle between the satellite A and the receiving antenna C of the receiver B, the electric wave can be easily received. It's gone. For this reason, even if the GPS receiver B is turned on, the receiver B and the receiving antenna C are in a building, a tunnel, or the like where radio waves do not reach or are hard to reach (hereinafter referred to as a radio wave unreceivable space). G while in
Not only can the position be confirmed by PS, but even if the user comes out of this radio wave unreceivable space to a place where radio waves can be received, the positioning state cannot be entered unless some time has passed for the reason described above. When using GPS in a patrol car, a fire engine, or an ambulance, it becomes possible to quickly confirm the position at least when the vehicle comes out of the radio wave incapable space and can receive the GPS radio wave from the GPS satellite A. Although it is desirable that this is not possible at present,
A method for achieving this has been strongly desired.

[0006] Further, in order to carry out maintenance, inspection, and repair of the GPS receiver B indoors, it is necessary to separately install an external antenna outdoors and connect the external antenna and the GPS receiver B. This is a few GPS receivers B
It is not a big problem to maintain, inspect, and repair, but in the case where a lot of GPS receivers B before shipment have to be inspected at a manufacturing plant, it is a great effort to connect an external antenna. Therefore, a more efficient method has been desired.

The object of the present invention is to achieve G
GPS that can receive PS radio waves so that you can quickly check your position after leaving the space where radio waves cannot be received, or that you can perform maintenance, inspection, repair, etc. of GPS receivers indoors. GP to a space where radio waves cannot be received
It is to provide an S radio wave retransmission method.

[0008]

As shown in FIG. 1, a method of retransmitting GPS radio waves to a GPS radio wave unreceivable space according to the present invention uses an external antenna 2 installed outdoors to transmit GPS radio waves transmitted from a GPS satellite 1. The received radio wave is received through the re-transmitting device 3 from the internal antenna 5 provided in the radio wave unreceivable space 4 in the building, the tunnel, etc.
It is characterized in that it is retransmitted within.

[0009]

According to the method of retransmitting the GPS radio wave to the GPS radio wave unreceivable space of the present invention, the GPS transmitted from the GPS satellite 1 is used.
The electric wave is received by the external antenna 2 installed outdoors, and the received electric wave is transmitted through the retransmitting device 3 from the internal antenna 5 provided in the electric wave unreceivable space 4 inside the building, the tunnel, etc. Therefore, the GPS radio wave can be received even in the same radio wave unreceivable space 4. As a result, the GPS receiver 6 in the radio wave unreceivable space 4 can also continuously acquire the frequency of the GPS radio wave and the almanac included in the GPS radio wave. The GPS satellite 1 can be promptly supplemented when the user comes to a place where the GPS radio wave of 1 can be directly received. That is, the position can be immediately entered. However, since the position of the external antenna 2 is shown as the position of the GPS receiver 6 in the radio wave unreceivable space 4, it is not possible to confirm its own exact position in the radio wave unreachable space 4.

[0010]

Embodiment 1 FIG. 1 shows an embodiment of a method for retransmitting GPS radio waves to a GPS radio wave unreceivable space according to the present invention. In FIG. 1, 1 is a GPS satellite orbiting the earth, 2 Is an external antenna capable of receiving GPS radio waves from the GPS satellite 1, and 3 is GPS received by the external antenna 2.
Retransmitting device for amplifying and outputting the signal, 4 is a radio wave unreceivable space where the radio wave from the satellite 1 in the building 10 does not reach directly, 5
Is an internal antenna that radiates the GPS signal output by the retransmitting device 3, and 6 is a GPS receiver in the radio wave unreceivable space 4.

The external antenna 2 is installed on the roof of the building 10 so as to easily receive the 1.2 GHz band radio waves transmitted from the GPS satellite 1 and the 1.5 GHz band radio waves.

The re-transmitting device 3 uses the G band of 1.5 GHz band.
A filter 11 for extracting the PS signal and the GPS signal in the 1.2 GHz band, and an amplifier 12 capable of amplifying the signals in both bands are provided, and the signal received by the external antenna 2 is filtered by the filter 1.
A GPS signal in the 1.5 GHz band and a GPS signal in the 1.2 GHz band are generated by 1 and these two GPS signals are amplified to a desired level by the amplifier 12 in the subsequent stage and output to the internal antenna 5. However, 1.5GHz GPS signal, 1.2G
Since the frequency of the GPS signal in the Hz band slightly changes due to the Doppler effect, it is preferable that the band width of the filter 11 has some margin.

The internal antenna 5 is an antenna capable of radiating radio waves in the 1.2 GHz band and radio waves in the 1.5 GHz band, and is installed in the radio wave unreceivable space 4 in the building 10. When the GPS signal is output from the retransmission device 3, the internal antenna 5 radiates the GPS signal toward the radio wave unreceivable space 4.

The GPS receiver 6 is a commercially available receiver and indirectly receives GPS radio waves output from the GPS satellite 1 via the external antenna 2, the retransmitting device 3 and the internal antenna 5. . Therefore, the receiver 6 uses the GPS
The transmission frequency of the satellite 1 is detected, and the almanac (satellite history) is continuously updated.
Therefore, even if the receiver 6 is taken out of the building 10, the exact position of the receiver is displayed immediately. When the GPS receiver 6 is inside the building 10, the installation position of the external antenna 2 is displayed on the receiver 6 as its own position.

[0015]

[Embodiment 2] Although the embodiment described above is a basic example, for example, the external antenna 2 is installed in a police station building, and the retransmission device 3 and the internal antenna 5 are installed in a garage of a patrol car (a space where radio waves cannot be received). ), And if the GPS receiver 6 is installed in the patrol car, the GPS receiver 6 can be positioned while the patrol car is waiting in the garage (however, the GPS receiver 6 is powered on). It can be kept in the state, and the position can be confirmed quickly by the GPS when dispatched.

[0016]

[Third Embodiment] In addition, if the external antenna 2 is installed outside the tunnel and the retransmitting device 3 and the internal antenna 5 are installed inside the tunnel (radio wave non-receiving space 4), the tunnel travels. Among them, the car with the GPS receiver 6 is G
Since the frequency and the almanac from the PS satellite 1 can be continuously acquired, even if the position of the user cannot be grasped, the position of the user can be immediately confirmed when leaving the tunnel.
Note that the 1 GHz band signal can be transmitted only about 50 m even with a low-loss coaxial cable, so the external antenna 2
When it is necessary to transmit the signal received in step 5 or more for 50 m or more, it is necessary to convert the 1 GHz band signal to a low intermediate frequency once and restore it to the original 1 GHz band signal near the internal antenna 5. .

[0017]

[Fourth Embodiment] Furthermore, if the external antenna 2 is installed on the roof of the GPS receiver manufacturing plant, and the retransmitting device 3 and the internal antenna 5 are installed in the plant (radio wave unreceivable space 4). Since the maintenance, inspection, repair, etc. of the GPS receiver 6 can be performed in the factory, the work efficiency can be greatly improved unlike the conventional method of connecting the external antenna.

[0018]

[Effects of the Invention] The GPS in the GPS radio wave unreceivable space of the present invention
The PS radio wave retransmission method has the following effects. ． By retransmitting GPS radio waves to the vehicle waiting in the garage, the position can be confirmed by GPS immediately when the vehicle leaves the garage. This is especially effective for patrol cars, fire trucks, ambulances, etc. that require quick dispatch. ． By retransmitting GPS radio waves to a place where radio waves cannot be received, such as in a tunnel or under an elevated road, the position can be confirmed by GPS immediately when the vehicle exits from under the tunnel or elevated road. ． The GPS system of the aircraft can be checked in the hangar by retransmitting GPS radio waves to the hangar of the aircraft. ． At a manufacturing plant of GPS-related equipment, G
If PS radio waves are retransmitted, the performance of the receiver and various adjustments can be easily performed in the factory without connecting an external antenna. This is especially convenient for factories handling a large amount of products because the work efficiency is improved. ． GPS in the paddock at car repair centers, etc.
If radio waves are retransmitted, adjustment, repair, and inspection of car navigation by GPS can be performed in the paddock. ． It is effective for indoor training in a surveying instrument using GPS and a satellite orbit history calculation system. ． Adjustment and inspection of GPS for ships can be easily done without connecting an external antenna. ． Adjustment of GPS clocks and pulse clocks using GPS can be performed easily without connecting an external antenna.

[Brief description of drawings]

FIG. 1A is a schematic view showing an embodiment of a method of retransmitting a GPS radio wave into a GPS radio wave unreceivable space according to the present invention;
FIG. 3B is a block diagram of a retransmission device used in the method in FIG.

FIG. 2 is a schematic diagram showing an outline of GPS.

[Explanation of symbols]

 1 GPS satellite 2 External antenna 3 Retransmission device 4 Radio wave unreceivable space 5 Internal antenna

Claims (1)

[Claims] 1. GPS transmitted from a GPS satellite (1)
An internal antenna (5) is provided which receives radio waves with an external antenna (2) installed outdoors and which receives the radio waves through a retransmitting device (3) in a radio wave unreceivable space (4) such as inside a building or tunnel. From the same radio wave unreceivable space (4) to a GPS radio wave unreceivable space.