JP2957506B2 - Event measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an event measuring apparatus mounted on a geosynchronous satellite and for measuring occurrence and location of a ground event such as lightning with high accuracy.

[0002]

2. Description of the Related Art As a typical prior art of a method for detecting a lightning occurrence position, for example, a technique of observing electromagnetic waves at which lightning occurs at a plurality of ground observing stations and measuring the occurrence position from a difference in observation time, and There is a technology for observing the position of occurrence using a television camera type sensor on an artificial satellite. These two
Of the three lightning observation technologies, the former technology is disclosed in Japanese Patent Laid-Open No. 7-434.
No. 75 publication. This is done by observing the discharge of lightning at three or more ground observation stations, specifying the time of lightning occurrence from the image synchronization signals of broadcast satellites received simultaneously,
The lightning position is measured from the time difference.

[0003] As the latter of the lightning observation techniques, a lightning mapper system (Lightning M) mounted on the US Meteorological Satellite GOES-8 is known.
apper System). This system is
The location of the lightning is monitored by a TV camera type two-dimensional CCD sensor for 24 hours from the geosynchronous orbit of the satellite.

[0004]

However, in the lightning observation technology described in Japanese Patent Application Laid-Open No. 7-43475, it is necessary to determine the distance from lightning from at least three stations in order to determine the lightning occurrence position. Because the observation range of electromagnetic waves generated from lightning is limited, only local observations can be supported, and therefore, for global lightning observations, countless observation stations are required and realized. Was difficult.

[0005] In the conventional lightning observation from artificial satellites by the lightning mapper system, observation by a TV camera type sensor from a geosynchronous orbit is necessary in order to constantly monitor the occurrence of lightning over a wide area on the ground. Due to the limitations of the number of CCD elements of the system and the two-dimensional CCD sensor, there is a problem that a resolution of only about 10 km can be obtained at the maximum. Furthermore, in order to constantly monitor lightning with an accuracy of about 1 km on the ground surface, a huge telescope and multiple
There is a problem that it is necessary to combine the two-dimensional CCD elements, and it is impossible to realize the two-dimensional CCD elements due to the limitation of the satellite weight and the technical problems of the current two-dimensional CCD elements.

Further, even when lightning does not occur, since data is always transmitted, the lightning observation operation rate is low, and there is much waste in transmission of observation data.

SUMMARY OF THE INVENTION The present invention solves the above-described problems. The observation from a geostationary satellite increases the observation area as compared with the case of observation by a ground station, and an event such as lightning occurs. To provide an event measurement device capable of realizing both 24-hour constant observation and high accuracy, and improving the operation rate and transmission efficiency by usually performing observations of weather / earth. With the goal.

[0008]

In order to achieve the above-mentioned object, an event measuring apparatus according to the first aspect of the present invention is mounted on a geosynchronous artificial satellite and monitors the occurrence and location of an event on the ground in a predetermined field of view. An event sensor, a fine event sensor that adjusts the visual field direction in accordance with the event occurrence position obtained based on the output of the coarse event sensor, and monitors an event in the visual field direction, based on the output of the fine event sensor identify the event occurrence position, and an image signal processing unit for outputting to the communication system by embedding the image data, the seminal event sensor, Sukyanmi
Scanning the ground in both directions east / west / south / north
A ground-based imager for ground-based observations
It is characterized by the following.

Further, event measurement apparatus according to the invention of claim 2 is the seminal event sensor, the mining lease event Se
Suspends ground observation when the sensor detects an event
The location of this event is automatically monitored with high resolution.
After a certain period of time,
Observation was restarted.

[0010]

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing the configuration of an event measuring device according to the present invention. Here, the event measuring device will be described as a lightning measuring device. In FIG. 1, reference numeral 1 denotes a fine lightning sensor as a fine event sensor which forms a part of an imager for performing normal ground observation and detects a lightning occurrence position with high accuracy.

The lightning sensor 1 includes two torque motors 5a and 5b driven by control signals, and front and rear and left and right (East / West) by these torque motors 5a and 5b.
A scan mirror 6 whose direction is changed in the north-south direction, and a reflected light from the scan mirror 6 are received, and a secondary reflector 21 provided at the center of the scan mirror 6 is sent to the scan mirror 6.
Further, it has a main reflecting mirror 22 for reflecting and inputting.

Reference numeral 23 denotes a through hole provided in the center of the main reflecting mirror 22, and the light reflected by the secondary reflecting mirror 21 passes through the through hole 23 to the visible two-dimensional CCD sensor 4. It is possible to enter. Reference numeral 2 denotes a coarse lightning sensor as a coarse event sensor attached to the fine lightning sensor 1.
Reference numeral 3 denotes a signal processing device including a signal processing unit and an image signal processing unit described later.

FIG. 2 is a block diagram mainly showing a signal system of the lightning measuring device. In FIG.
Consists of a condenser lens 12 for observing lightning as an event facing the earth, and a visible two-dimensional CCD sensor 7 for receiving an image of lightning. Reference numeral 24 denotes an amplifier for amplifying the output signal of the visible two-dimensional CCD sensor 7, and reference numeral 3A receives a response signal from the visible two-dimensional CCD sensor 7 via the amplifier 24, performs an operation, and outputs the result as lightning position information 9. It is a signal processing unit.

Reference numeral 8 denotes a scan mirror control unit which receives the lightning position information 9 and outputs an east-west direction control signal 10 and a north-south direction control signal 11 to each of the torque motors 5a and 5b. Each control signal 1
Two torque motors 5a, 5 driven by 0, 11
By b, the direction of the scan mirror 6 can be adjusted in each of the east-west direction and the north-south direction.

Reference numeral 18 denotes an amplifier for amplifying a light reception signal of light incident on the visible two-dimensional CCD sensor 4 via the scan mirror 6, the main reflection mirror 22, and the secondary reflection mirror 21, and reference numeral 3B denotes this amplifier 18 Signal processing unit for processing the lightning position signal and earth image signal obtained through
Is an artificial satellite communication system for modulating the data 14 including the lightning position signal and the earth image signal and transmitting the modulated data 14 to the ground.

Next, the operation will be described. First, the operation before the occurrence of lightning will be described with reference to FIGS. The visible two-dimensional CCD sensor 7 of the coarse lightning sensor 2 has a visual field range 16 in which the entire earth can be observed, and one pixel 7a of the visible two-dimensional CCD sensor 7 is the minimum observation range. The visible two-dimensional CCD sensor 7 has a configuration of about 500 × 500 pixels and has a ground surface resolution of about 25 km.

On the other hand, the visible two-dimensional CC of the lightning sensor 1
The D sensor 4 has an entire visual field range 17 corresponding to the size of one pixel 7 a of the visible two-dimensional CCD sensor 7 of the coarse lightning sensor 2. By scanning 19 and north-south scanning 20, the entire earth is observed, an image of the entire earth is obtained, and earth observation such as weather is performed. The lightning sensor 1 has a visible two-dimensional CC.
The number of pixels 4a of the D sensor 4 is about 20 × 20, and the ground surface resolution is about 1.25 Km.

Next, the operation after the lightning observation will be described with reference to FIGS. 5 and 6 according to the time chart of FIG. When a lightning strike occurs at a lightning strike point 25, the lightning is observed on a specific pixel 7b on the visible two-dimensional CCD sensor 7 in the coarse lightning sensor 2 (observation point 26). Therefore, a lightning response signal as observation data observed by the visible two-dimensional CCD sensor 7 is input to the signal processing unit 3A via the amplifier 24.

When there is an output from the rough lightning sensor 2, the signal processing unit 3A performs a comparison process with a preset signal level and a rising / falling waveform reference to determine whether or not lightning has occurred. At the same time, the detection pixel position is extracted (lightning identification and detection pixel position extraction time 28).
If it is determined that lightning has occurred, the lightning occurrence pixel position is output to the scan mirror control unit 8 as lightning position information.
The scan mirror control unit 8 moves the view direction of the fine lightning sensor 1 to one specific pixel 7b of the visible two-dimensional CCD sensor 7, which is the lightning occurrence area, at the time point 30 of the mirror drive control to the lightning position. Then, a mirror drive signal as a drive signal is output to the torque motors 5a and 5b to operate the scan mirror 6.

In this manner, the scan mirror 6 is moved to the position shown in FIG.
Operate in the direction of the arrow shown in Fig.
Is rotated, and after the scan mirror 6 moves from a portion where the pixel 4b is located to the pixel 4c corresponding to the lightning occurrence position (motor stop time 32), the lightning sensor 1 moves the gaze direction to the same place for a preset time. While fixed, the occurrence of lightning is monitored at the pixel 4c, and the image processing unit processes / transmits the lightning image data. Then, when lightning is regenerated in the same lightning occurrence area, the visible two-dimensional CC
The D sensor 4 detects lightning occurrence (lightning occurrence detection time point 36),
The response signal is output to the image signal processing unit 3B.

Then, the image signal processing unit 3B identifies and determines whether or not lightning has occurred based on the response signal in the same manner as when the rough lightning sensor 2 performs the lightning. An accurate lightning occurrence position is specified from the pixel 4c in the two-dimensional CCD sensor 4, the position data is embedded in image data, and output to the communication system 15 (position information output time 38). In this way, the fine lightning sensor 1 performs lightning observation for a certain time thereafter, and then returns to the imager mode, which is a normal image acquisition. At this time, the scan mirror control unit 8 starts rescanning from the pixel 22 at the position on the scanning line where the previous observation was interrupted, and restarts earth observation and the like.

In the above-described embodiment, the description has been given of a method for detecting a lightning occurrence position. However, by changing or adding the lightning identification processing algorithm part of the signal processing unit, the other events, For example, the present invention can be applied to an optical measurement device that performs an emergency monitor at the time of a disaster such as a volcanic eruption, a large fire, or an earthquake.

[0024]

As described above, according to the first aspect of the present invention, a coarse event sensor mounted on a geosynchronous satellite and monitoring the occurrence and location of an event on the ground in a predetermined visual field range; The visual field direction is adjusted according to the event occurrence position obtained based on the output of the event sensor, and a fine event sensor that monitors the event in the visual field direction, and the event occurrence position is specified based on the output of the fine event sensor. , and an image signal processing unit for outputting to the communication system by embedding the image data, the seminal event Se
East / west / north / north
For ground observation, which performs ground observation by scanning in the direction
Because it has a major function, observations from geostationary satellites can be used to expand the observation area compared to observations made by ground stations. It is possible to improve both the operating rate and the transmission efficiency by making observations of weather and the earth, etc. possible. The effect that it can be realized is obtained. Furthermore, thunder
Measurement of any unexpected events can be performed in normal ground observations.
And increase the operating rate of the measuring device.
The effect is obtained.

According to the second aspect of the present invention, the fine event sensor includes an event
When the occurrence of an event is detected, ground observation is suspended and this event
Automatically observes the location of the event at high resolution, and after a certain period of time
And resume ground observation from the point where it was interrupted
Event measurement and normal image
Continuous and effective ground-based observations
The effect is that it can be performed efficiently and accurately.
You.

[0026]

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an entire event measuring device according to an embodiment of the present invention.

FIG. 2 is a block diagram mainly showing a signal processing circuit of the event measuring device shown in FIG. 1;

FIG. 3 is an explanatory diagram showing pixels on the coarse lightning sensor in FIG. 1;

FIG. 4 is an explanatory view showing pixels on the fine lightning sensor in FIG. 1;

FIG. 5 is an explanatory diagram showing pixels on a coarse lightning sensor when a lightning position is detected.

FIG. 6 is an explanatory diagram showing pixels on a fine lightning sensor when a lightning position is detected.

FIG. 7 is a time chart showing an operation state of each part of the circuit in FIG. 2 when a lightning strike occurs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fine lightning sensor (fine event sensor) 2 Fine lightning sensor (coarse event sensor) 3B Image signal processing part 6 Scan mirror 15 Communication system

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01W 1/08 G01S 13/95 G01W 1/16 G01V 1/00

Claims (2)

(57) [Claims] 1. A coarse event sensor mounted on a geosynchronous satellite for monitoring the occurrence and occurrence position of an event on the ground in a predetermined visual field range, and a visual field according to an event generation position obtained based on an output of the coarse event sensor. A fine event sensor whose direction is adjusted to monitor the event in the direction of the visual field; and an image signal processing unit that identifies the event occurrence position based on the output of the fine event sensor, embeds the image in the image data, and outputs it to the communication system. has the fine event sensor is ground by the scanning mirror
Scanning in both east / west / north / south directions
An event measurement device comprising an imager for ground observation to be performed . 2. The system according to claim 1, wherein the fine event sensor is provided with
Ground observation when the sensor detects an event
And automatically observe the location of this event with high resolution
After a certain period of time,
2. The event according to claim 1, wherein the observation is restarted.
Measurement device.