JP5604756B2 - Data collection system by geostationary satellite - Google Patents

Description

  The present invention relates to a satellite data collection system.

  Up to now, environmental observation data from mountains, oceans, etc. has been collected from signals sent from various sensors installed on large buoys in the ocean. As an existing system for realizing such data collection, there is a data collection system using a satellite (Patent Document 1). In this data collection system, a transmission signal from a sensor installed in a buoy is relayed by a satellite and transmitted to a ground station. The ground station receives data from satellites, collects data, and analyzes / analyzes the collected data.

  However, the conventional data collection by satellites has the disadvantage that only the signal from the area covered by the satellite antenna can be detected, and the position of the buoy equipped with the sensor cannot be specified. In addition, the reception capability of the satellite is insufficient, and a large transmission power is required on the buoy side, which becomes an obstacle to system construction and increases in cost due to the increase in size of the buoy.

  For these reasons, conventional data collection systems using satellites have problems to be improved.

JP2004-21778

  An object of the present invention is to improve the shortcomings of conventional data collection systems by using a signal transmitted from a sensor having a small, lightweight and small terminal function of a mobile phone class with GPS, which has been widely disseminated. It intends to provide a data collection system.

  The present invention is a sensor information collection system using a satellite communication line, which is equipped with a large reflector antenna having high reception sensitivity on a satellite and has a size and transmission capability of a GPS mobile phone (GPS mobile terminal) class. The sensor signal can be received from a sensor having the function of a small terminal, and the feasibility, convenience, and cost reduction of the construction of the sensor network are greatly improved, and includes the following configurations and functions.

a. The large reflector antenna mounted on the satellite is capable of receiving sensor signals from a sensor having a function (transmission / reception function) of a small cellular phone-class terminal with GPS and a function of observing predetermined environmental data such as temperature and pressure.
b. The sensor signal should include sensor position information obtained by the GPS function.
c. The sensor signal shall include the GPS time of the sensor obtained by the GPS function.
d. Including a reverse communication line to the sensor to notify the status of sensor signal acceptance.
e. The backward communication to the sensor should include transmission timing information that specifies intermittent transmission from the sensor.

  According to the present invention, the burden on the manufacture and installation of a sensor is achieved by transmission from a small and lightweight sensor that functions as a terminal having the same size and transmission / reception function as a GPS mobile phone class and a predetermined environmental data observation function. It is possible to provide a data collection system using satellites quickly and reliably by using highly accurate position information of sensors while greatly reducing the number of sensors.

It is a figure for demonstrating the structure of the data collection system by embodiment of this invention. It is the figure which showed an example of the large sized reflector antenna by embodiment of this invention mounted in the geostationary satellite of FIG. It is the figure which showed embodiment of the earth environment observation sensor which has a function as a small terminal which has the magnitude | size of a mobile telephone class with GPS, and a transmission / reception capability. It is the figure which showed an example of schematic structure of the global environment observation sensor shown by FIG. It is the figure which showed the example of the data structure of the sensor signal and sensor signal acquisition signal exchanged between a global environment observation sensor and a geostationary satellite in embodiment of this invention. It is a figure for demonstrating the case where a service provider develops the service which provides the observation data obtained by the data collection system by embodiment of this invention to a user.

  The data collection system according to the present invention receives sensor signals from global environment observation sensors deployed in the ocean, mountains, etc. by a large reflector antenna with excellent reception performance mounted on a satellite. The satellite transmits the received sensor signal to the ground station. The ground station collects highly useful and efficient observation data based on the global environment observation data included in the received signal, information on the position of the global environment observation sensor by GPS positioning, acquired GPS time, and the like. That is, environmental observation data is acquired as data corresponding to position information and acquisition time information where the global environmental observation sensor is deployed.

  For example, it is not essential to use a conventional 406 MHz band signal as the sensor signal, and it is possible to use a frequency band assigned to satellite mobile communication. Since the sensor signal can be transmitted intermittently at the timing instructed to the global environment observation sensor by the sensor signal acquisition signal transmitted from the satellite to the global environment observation sensor, a large number of global environment observation sensors Control is performed so that information does not become congested (collision) even in the presence of. Such control is executed by relaying an instruction from the control unit of the ground station via a satellite and transmitting it as a sensor acquisition signal to the earth observation sensor.

  The present invention is based on a global environment observation sensor having a function as a small GPS terminal (mobile terminal) having a GPS mobile phone (mobile terminal) class size, transmission power, and reception function, which is deployed in the ocean, mountains and the like. In order to receive a sensor signal (observation signal), this is a data collection system in which a large reflector antenna is mounted on a satellite and has the following configuration requirements.

  (1) The satellite has a large reflector antenna for improving the reception performance of sensor signals.

  The large reflector antenna is not of the several meter class, but has a large reflector of 10 m or more, preferably 10 to 30 m. Such a large reflector is launched by a rocket together with a satellite, and when stored in the rocket, it is folded and stored so that it fits within the fairing together with the satellite. After reaching a predetermined orbit in outer space, a desired orbit is obtained on the orbit. Expanded into a shape (parabolic). After deployment, the large reflector antenna is directed to a desired region on the earth where the earth environment observation sensor exists.

  (2) The global environment observation sensor deployed in the ocean and mountains does not require a large buoy for mounting it, and is as large as a small mobile phone class terminal with GPS and transmission. It has a function for observing predetermined environmental data such as electric power, temperature and pressure.

  (3) The global environment observation sensor has a GPS reception function, a positioning function, and a GPS reinforcement signal reception function in addition to a communication function similar to that of a small terminal.

  (4) The sensor signal transmitted from the earth environment observation sensor is received by the large reflector antenna through the uplink line, and is received and collected by the ground station via the satellite on which it is mounted. In communication between the satellite and the earth environment observation sensor, a signal including sensor signal acquisition information indicating that the sensor signal has been received is transmitted to the earth environment observation sensor via a reverse line (downlink line). Includes functionality. This sensor signal acquisition information includes transmission timing instruction information for the global environment observation sensor, in addition to information for notifying completion of sensor signal reception in the satellite.

  The theoretical and actual aspects of the embodiment of the present invention will be described below.

[Theoretical explanation]
A signal level S at which a sensor signal from a global environment observation sensor deployed in the ocean or mountains is received by a satellite can be expressed by the following equation (1).

S = P · G · Gs · {(λ / 4) · π · L} ² (1)
In Equation (1), P is the transmission power of the earth environment observation sensor, and G is the antenna gain on the earth environment observation sensor side. L is the propagation distance of the sensor signal, λ is the transmission signal wavelength of the sensor signal, and Gs is the antenna gain of the satellite.

  If the transmission power P and the antenna gain G are reduced in order to reduce the weight of the earth environment observation sensor side, the satellite side antenna gain Gs needs to be significantly improved in order to obtain the same reception power. The antenna gain of a general satellite is proportional to the square of the antenna aperture diameter, and it is necessary to mount a large antenna in order to increase the antenna gain.

  When launching a satellite, a large reflector antenna is generally in a form in which the reflector is folded and stored in the fairing of the rocket, and the folded reflector is deployed on the satellite orbit. A mesh type suitable for deployment is used for the reflecting mirror. In previous data collection systems, the feasibility of a large reflector mounted on a satellite was not established at the time of construction, and the antenna gain Gs in equation (1) was small, so transmission of the earth environment observation sensor The system had to be enlarged.

  In order to increase the certainty of information collection using sensor signals, it is important to locate the global environment observation sensor. In the data collection system according to the present embodiment, the sensor signal transmitted from the global environment observation sensor includes GPS positioning information (position information of the global environment observation sensor), time information (data acquisition time), and the like. Thereby, the position measurement of the global environment observation sensor can be performed on the order of about 1 to 5 m, and the global environment monitoring information and the geographical information in the ground station can be associated with each other.

  Conventional data collection methods have no positioning information by GPS, and there is a large error in the measured position, making it difficult to analyze / analyze the collected data. On the other hand, it is known that a GPS reinforcement signal is used to improve positioning accuracy based on information from a GPS monitor station whose location is known. Therefore, the global environment observation sensor in the data collection system according to the present embodiment can obtain highly accurate positioning information using the GPS reinforcement signal.

  Further, by using a sensor signal acquisition signal, which will be described later, on which a GPS reinforcement signal can be superimposed, the reception confirmation of the sensor signal from the satellite is transmitted to the earth environment observation sensor side, or the sensor is sent to the earth environment observation sensor side. Since the timing of signal transmission can be specified, an efficient and highly reliable data collection network can be constructed.

[Practical explanation]
FIG. 1 shows a schematic configuration of a data collection system according to an embodiment of the present invention. The data collection system includes a global environment observation sensor 11, a geostationary satellite 12, a large reflector antenna 13 (FIG. 2) mounted on the geostationary satellite 12, a global environment observation ground station 14, and a GPS control station 15. Although only one global environment observation sensor 11 is shown in FIG. 1, one or more global environment observation sensors are provided in the ocean or mountains. When deployed in the ocean, it is installed on a buoy or the like, but it does not require a large buoy.

  Sensor signals including temperature and other measurement information measured and transmitted by the global environment observation sensor 11 and sensor signals from other global environment observation sensors are sequentially received by the large reflector antenna 13 mounted on the geostationary satellite 12. Then, they are collectively transmitted to the earth environment observation ground station 14 via the geostationary satellite 12. The earth environment observation ground station 14 processes the received sensor signal and creates observation data. This observation data is used for providing weather forecasts, disaster predictions, and other various services. The GPS control station 15 transmits a GPS signal.

  FIG. 3 shows an embodiment of a global environment observation sensor having a function as a small terminal having a size of a cellular phone class with GPS and a transmission / reception capability. The global environment observation sensor 20 can be realized by a device similar to that provided as a mobile phone. Therefore, the sensor signal and the sensor signal acquisition signal exchanged between the earth environment observation sensor 20 and the geostationary satellite 26 have a data structure shown in FIG.

  As shown in FIG. 5A, the sensor signal has a data structure including a preamble, a terminal ID (Identification Data), position information and time information by GPS, temperature, other measurement information, and a postamble. have.

  On the other hand, as shown in FIG. 5 (b), the sensor signal acquisition signal includes a preamble, a terminal ID, a GPS reinforcement signal for improving positioning accuracy, encrypted sensor signal acquisition information, and a postamble. And has a data structure consisting of As described above, the sensor signal acquisition information includes not only the reception of the sensor signal on the satellite but also the transmission timing instruction information for the global environment observation sensor. Needless to say, not only the sensor signal acquisition information but also the information in FIGS. 5A and 5B may be encrypted as necessary.

  FIG. 4 shows an example of a schematic configuration of the global environment observation sensor 20 shown in FIG. The global environment observation sensor 20 incorporates a battery (not shown) in addition to the sensor unit 21, the transmission / reception unit 22, the antenna unit 23, and the branching unit 24. The transmission / reception unit 22 includes a GPS signal reception unit 22-1, a sensor signal transmission unit 22-2, and an advance signal reception unit 22-3. The sensor unit 21 has not only a measurement function, but also a GPS signal and an accuracy signal decoding function, a function for converting and configuring measurement information into a format necessary for transmission, a function for controlling the transmission / reception unit 22, a battery saving function, and the like. .

  FIG. 6 is a diagram for explaining a case where a service provider develops a service that provides observation data obtained by the data collection system to a user.

  The infrastructure provider 31 provides infrastructure for ordering, maintaining, and operating satellites, and the service provider 32 collects sensor information based on this infrastructure. The GPS reinforcement signal generator 33 generates, transmits, and manages GPS reinforcement signals to the service provider 32. In order to receive the service for providing the global environment observation data from the service provider 32, the user 34 registers his / her ID having this function and pays a service fee to the service provider 32. The service provider 32 manages this.

DESCRIPTION OF SYMBOLS 11, 20 Earth environment observation sensor 12 Geostationary satellite 14 Earth environment observation ground station 15 GPS control station 21 Sensor part 22 Transmission / reception part 23 Antenna part 24 Branch part 31 Infrastructure provider 32 Service provider 33 GPS reinforcement signal generator 34 User

Claims (4)

It has a GPS signal receiver and a sensor signal acquisition signal receiver, has the same size and transmission capability as a GPS mobile phone terminal, has a GPS function and a predetermined environmental data observation function, An environmental observation sensor having a sensor signal transmission unit for transmitting a signal including the observed environmental data as a sensor signal ;
A geostationary satellite having a transmission / reception function by a reflector antenna exceeding 10 m and communicating between the environmental observation sensor and the earth station;
See containing and a earth station for collecting environmental data from one or more of the environmental monitoring sensors transmitted via the geostationary satellite,
Information transmitted from the geostationary satellite to the environmental observation sensor and informing completion of reception of the sensor signal from the environmental observation sensor, and the sensor signal acquisition signal including a GPS reinforcement signal for improving positioning accuracy, A data acquisition system using a geostationary satellite , which is received by the sensor signal acquisition signal receiver .   The data collection system using a geostationary satellite according to claim 1, wherein the reflector antenna is a foldable type.   3. The data collection system using a geostationary satellite according to claim 1, wherein positioning information based on GPS reception and GPS time are placed on the sensor signal. 2. The data collection system using a geostationary satellite according to claim 1 , wherein the sensor signal acquisition signal further includes information indicating a transmission timing of the sensor signal in the environmental observation sensor.

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