Aircraft-mounted weather radar, aircraft, and weather observation system

Abstract

To provide technique such as an airborne weather radar that can materialize both of a weather observation for a safe flight of an aircraft, and a weather observation for reinforcement of the weather observation and the like.SOLUTION: An airborne weather radar according to the present technique comprises: an antenna; and a control unit. The control unit implements first weather observation observing by the antenna, weather of a first area with directionality in an advance direction of an aircraft, and a second weather observation observing by the antenna, weather of a second area different from the first area.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to technologies such as aircraft-mounted weather radars.

Background Art

[0002] Since an aircraft is a vehicle that flies using the atmosphere, it is inevitable that weather has a great impact on its operation. Therefore, today's safe and secure aircraft operations are carried out under various flight supports based on weather observations and weather forecasts. Aircraft operations can be broadly classified into a cruise phase and a takeoff / landing phase. For the cruise phase, weather forecasts several hours ahead are heavily used, and for the takeoff / landing phase, weather observations (and short-term forecasts within one hour by extrapolating weather observations outside the observation time) are heavily used.

[0003] While enjoying the benefits of weather observations and weather forecasts in this way, aircraft also contribute to strengthening weather observations and improving weather forecasts. Aircraft perform on-site observations of atmospheric pressure and temperature in the sky during flight, and the observation results of the vertical distribution (accurately, the distribution on the flight route) of such physical quantities contribute to improving the accuracy of weather forecasts (see Non-Patent Document 1). Also, in 2019, due to the spread of Covid-19, the number of aircraft operations decreased sharply, and as a result, it was reported that the accuracy of weather forecasts decreased (see Non-Patent Document 2).

[0004] Due to its characteristics, a weather radar can obtain very detailed weather information in a short-distance area, and the detail is lost as the distance increases. As can also be seen in recent research on weather radar networks, by using a large number of short-distance radars for observation, the area that can be observed in detail expands, and the overall observation performance improves. Since aircraft used in civil air transportation are basically equipped with weather radars, many weather radars are in operation in terms of the entire aircraft operation, and it has the advantages shown by research on weather radar networks (see Non-Patent Document 3).

Prior Art Documents

Non-Patent Documents

[0005] [Non-Patent Document 1] James, E. P., and S. G. Benjamin, 2017: Observation system experiments with the hourly updating Rapid Refresh model using GSI hybrid ensemble-variational data assimilation. Mon. Wea. Rev., 145, 2897-2918, https: / / doi.org / 10.1175 / MWR-D-16-0398.1 [Non-Patent Document 2] James, Eric P., Stanley G. Benjamin, and Brian D. Jamison. " Commercial-Aircraft-Based Observations for NWP: Global Coverage, Data Impacts, and COVID-19", Journal of Applied Meteorology and Climatology 59, 11 (2020): 1809-1825, accessed Feb 2, 2021, https: / / doi.org / 10.1175 / JAMC-D-20-0010.1 [Non-Patent Document 3] D. J. McLaughlin, D. Pepyne, B. Philips, J. Kurose, M. Zink, D. Westbrook, et al., "Short-wavelength technology and the potential for distributed networks of small radar systems", Bull. Amer. Meteorol. Soc., vol. 90, no. 12, pp. 1797-1817, Dec. 2009. [Non-Patent Document 4] E. Yoshikawa et al., "MMSE Beam Forming on Fast-Scanning Phased Array Weather Radar," in IEEE Transactions on Geoscience and Remote Sensing, vol. 51, no. 5, pp. 3077-3088, May 2013, doi: 10.1109 / TGRS.2012.2211607. [Non-Patent Document 5] E. Yoshikawa, T. Ushio and H. Kikuchi, "A Study of Comb Beam Transmission on Phased Array Weather Radars," in IEEE Transactions on Geoscience and Remote Sensing, doi: 10.1109 / TGRS.2020.3029875. [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, current aircraft-mounted weather radars are specialized for the purpose of ensuring the safety of the aircraft on which they are mounted. Therefore, they can observe the weather only in a limited area in front of the aircraft, and in principle, the observed weather information is displayed on the in-flight screen and discarded at the same time.

[0007] In view of the above circumstances, an object of the present technology is to provide a technology such as an aircraft-mounted weather radar that can realize both weather observation for the safe flight of an aircraft and weather observation for reinforcement of weather observation and the like. [Means for Solving the Problems]

[0008] To achieve the above object, an aircraft-mounted weather radar according to the present technology includes an antenna and a control unit. The control unit performs a first weather observation of observing the weather in a first area having directivity in the traveling direction of the aircraft by the antenna, and a second weather observation of observing the weather in a second area different from the first area by the antenna.

[0009] In this way, in the aircraft-mounted weather radar, by performing the first weather observation and the second weather observation, it is possible to achieve both the weather observation for the safe flight of the aircraft and the weather observation for reinforcing the weather observation, etc.

[0010] In the aircraft-mounted weather radar, the antenna may be a phased array antenna.

[0011] In the aircraft-mounted weather radar, the control unit may perform the first weather observation and the second weather observation in a time-division manner.

[0012] In the aircraft-mounted weather radar, in the second weather observation, the control unit may control the phased array antenna to perform an adaptive scan, thereby skipping a non-specific area and scanning a specific area in the second area.

[0013] In the aircraft-mounted weather radar, in the second weather observation, the control unit may identify the specific area and the non-specific area in the second area before the adaptive scan.

[0014] In the aircraft-mounted weather radar, the control unit may identify the specific area and the non-specific area by scanning the entire second area with the phased antenna.

[0015] The aircraft-mounted weather radar may further include an imaging device for imaging the entire second area. In this case, the control unit may identify the specific area and the non-specific area based on the image information from the imaging device.

[0016] In the aircraft-mounted weather radar, the specific area may be a precipitation area, and the non-specific area may be a non-precipitation area.

[0017] In the aircraft-mounted weather radar, the control unit may execute the first weather observation and the second weather observation simultaneously and in parallel.

[0018] In the aircraft-mounted weather radar, the control unit may perform simultaneous observation of the first area and the second area by controlling the phased array antenna to execute angle imaging.

[0019] In the aircraft-mounted weather radar, the second area may be wider than the first area.

[0020] The aircraft-mounted weather radar may further include a weather information processing unit that estimates the weather situation based on the information obtained from the first weather observation and the second weather observation.

[0021] In the aircraft-mounted weather radar, a communication unit that transmits the relevant information to an external device that receives and collects the relevant information related to at least the information obtained from the second weather observation among the first weather observation or the second weather observation from each aircraft may be further provided.

[0022] In the aircraft-mounted weather radar, the external device may estimate the overall weather situation on the ground based on the relevant information from each aircraft.

[0023] The aircraft according to the present technology includes an aircraft-mounted weather radar. The aircraft-mounted weather radar has an antenna and a control unit. The control unit performs a first weather observation of observing the weather in a first area having directivity in the traveling direction of the aircraft with the antenna, and a second weather observation of observing the weather in a second area different from the first area with the antenna.

[0024] The external device according to the present technology is an external device that receives and collects related information related to at least the information obtained by the second weather observation among the first weather observation or the second weather observation from each aircraft equipped with an aircraft-mounted weather radar having an antenna, a first weather observation for observing the weather in a first area having directivity in the traveling direction of the aircraft with the antenna, and a control unit that executes a second weather observation for observing the weather in a second area different from the first area with the antenna.

Effects of the Invention

[0025] As described above, according to the present technology, it is possible to provide a technology such as an aircraft-mounted weather radar that can realize both weather observation for safe flight of an aircraft and weather observation for reinforcement of weather observation.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0028] ≪First Embodiment≫ <Overall Configuration of Weather Observation System> FIG. 1 is a diagram showing a weather observation system 100 according to a first embodiment of the present technology. As shown in FIG. 1, the weather observation system 100 includes an aircraft-mounted weather radar 10, an external device 20, and a weather observation device 30.

[0029] The aircraft-mounted weather radar 10 is mounted on each aircraft 1 and used. The external device 20 is installed and used, for example, in an operating company of the aircraft 1, a company providing weather information services, a government agency (Japan Meteorological Agency), etc. The external device 20 receives and collects the observation information of the weather observed by each aircraft 1, and infers the overall weather situation on the ground. The weather observation device 30 is, for example, a ground-mounted weather radar, a wind profiler, a radiosonde, etc. Note that the weather observation device 30 can be omitted.

[0030] [Aircraft-Mounted Weather Radar 10] The aircraft-mounted weather radar 10 has a radar unit 13, a weather information processing unit 14, a current weather display unit 15, a predicted weather display unit 16, and a communication unit 17.

[0031] (Radar Unit 13) The radar unit 13 includes a phased array antenna 11 and a control unit 12 that controls the phased array antenna 11.

[0032] The control unit 12 is realized by hardware or a combination of hardware and software. The hardware is configured as part or all of the control unit 12, and examples of such hardware include a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a combination of two or more of these. Note that the same applies to the weather information processing unit 14 in the aircraft-mounted weather radar 10 and the weather information processing unit 24 in the external device 20.

[0033] In the present embodiment, the control unit 12 performs the first weather observation and the second weather observation by controlling the phased array antenna 11. The first weather observation is a weather observation for the safe flight of the aircraft 1. The second weather observation is a weather observation for enhancing weather observations, improving weather forecasts, etc. Note that the second weather observation is typically an overall weather observation within about 12 km where weather phenomena exist.

[0034] Note that the observation quantities obtained by the first weather observation and the second weather observation are typically radar reflectivity factors. Further, this observation quantity may include Doppler velocity, Doppler velocity width, reflectivity difference, cross-polar correlation coefficient, cross-polar phase difference, and specific cross-polar phase difference.

[0035] FIG. 2 and FIG. 3 are a top view and a side view showing the first region R1 observed by the first weather observation and the second region R2 observed by the second weather observation, respectively.

[0036] As shown in FIGS. 2 and 3, the first region R1 observed in the first meteorological observation is a fixed region having directivity in the traveling direction of the aircraft 1. Further, as shown in FIGS. 2 and 3, the second region R2 observed in the second meteorological observation is a region different from the first region R1 (a region having directivity in a direction different from the first region R1), and is a region wider than the second region R2. That is, in the second meteorological observation, in order to reinforce meteorological observation, improve meteorological prediction, etc., meteorological observation is performed over as wide a range as possible, such as the entire lower side of the aircraft 1, rather than a narrow range only in front of the aircraft 1.

[0037] The first region R1 and the second region spread radially from the vicinity of the tip of the aircraft 1 (the attachment position of the phased array antenna 11). The angle θ1 around the vertical axis in the first region R1 (see FIG. 2) is, for example, about ±50° to ±60° with respect to the front direction of the aircraft 1. Also, the angle φ1 around the horizontal axis (axis in the left-right direction) in the first region R1 (see FIG. 3) is, for example, about ±5° to ±10° with respect to the front direction of the aircraft 1.

[0038] Also, the angle θ2 around the vertical axis in the second region R2 (see FIG. 2) is, for example, about ±75° to ±90° with respect to the front direction of the aircraft 1. Also, the angle φ2 around the horizontal axis (axis in the left-right direction) in the second region R2 (see FIG. 3) is, for example, about ±20° to ±30° with respect to the direction of the depression angle of 40° to 60°.

[0039] In the examples shown in FIGS. 2 and 3, the second region R2 is the lower side of the aircraft 1, but the second region R2 may be the upper side, right side, left side, or rear side of the aircraft 1. Typically, the second region R2 may be any region as long as it is a region different from the first region R1 (and as long as it is a region wider than the second region R2).

[0040] Here, if only the first weather observation and the second weather observation are to be performed, the radar unit 13 for the first weather observation and the radar unit 13 for the second weather observation may be provided separately. However, in such a configuration where two separate radar units 13 are provided, costs, weight, size, etc. will increase, making it difficult to mount on the aircraft 1. Therefore, in the present embodiment, the first weather observation and the second weather observation are realized by a single radar unit 13.

[0041] Also, in the present embodiment, the control unit 12 alternately repeats the first weather observation and the second weather observation in a time-division manner. FIG. 4 is a time-series diagram of the first weather observation and the second weather observation.

[0042] The period t1 in the first weather observation is typically on the order of several seconds to several tens of seconds. Also, the period t2 in the second weather observation is typically on the order of several seconds (a period that does not impair the flight safety of the aircraft 1). Also, the cycle T from the previous second weather observation to the current second weather observation is typically on the order of several seconds to several tens of seconds.

[0043] Here, when the first weather observation and the second weather observation are alternately repeated in a time-division manner as in the present embodiment, there are the following problems. That is, while the weather in the second area R2 is being observed in the second weather observation, the weather in the first area R1 cannot be observed, which reduces the flight safety of the aircraft 1.

[0044] Therefore, in the present embodiment, in order to complete the second weather observation in a short period of time at high speed, the control unit 12 controls the phased array antenna 11 to perform an adaptive scan.

[0045] The adaptive scan will be described. The adaptive scan is a technique of scanning only a specific area and skipping areas other than the specific area (non-specific areas). This adaptive scan utilizes the advantage that the antenna directivity can be instantaneously changed by electronic scanning using the phased array antenna 11.

[0046] The adaptive scan by this phased array antenna 11 can perform the scan at a higher speed than the mechanical scan by a mechanical movable antenna. In the case of the mechanical scan of the mechanical movable antenna, it is impossible to skip an unspecified area because of inertia.

[0047] In the present embodiment, in the second weather observation, the control unit 12 executes processing such as skipping a non-precipitation area (an area other than the precipitation area) and scanning only the precipitation area (an area where rain, snow, sleet, hail, etc. are falling) by adaptive scanning.

[0048] FIG. 5 is a diagram showing a state where a non-precipitation area is skipped and only the precipitation area is scanned by adaptive scanning.

[0049] Here, in order to skip the non-precipitation area and scan only the precipitation area, it is necessary to know in which direction the precipitation area exists (the angular distribution of the presence or absence of precipitation). That is, it is necessary to specify the precipitation area and the non-precipitation area before the adaptive scan.

[0050] Two methods can be cited for this method. The first method is a method in which the control unit 12 controls the phased array antenna 11 to scan the entire second area R2 in the second weather observation and specifies the precipitation area and the non-precipitation area. Since the determination of the presence or absence of precipitation can be performed in a very short period compared to the case of observing the intensity of precipitation, etc., it does not go against the purpose of completing the second weather observation in as short a period as possible.

[0051] On the premise that it is known in which direction the precipitation area exists (the angular distribution of the presence or absence of precipitation), by scanning only the precipitation area by adaptive scanning, detailed weather observation (second weather observation) such as the intensity of precipitation in the precipitation area can be performed. In this case, in the second weather observation, it is also possible to focus on observing the periphery of a region with significant changes, or to determine the precipitation area to be observed later based on a short-term prediction of the precipitation area.

[0052] The second method is a method in which the control unit 12 identifies the precipitation area and the non-precipitation area based on the image information from an imaging device (optical camera) that images the entire second area R2 in the second weather observation. In this case, an imaging device is further added to the aircraft-mounted weather radar 10.

[0053] The discrimination of the precipitation area and the non-precipitation area based on the image information is not so easy, but it is considered that the accuracy of the discrimination can be improved by a discrimination algorithm using machine learning. Note that the imaging device may be a camera that can image not only visible light but also infrared rays and ultraviolet rays. Further, the imaging device may be a multispectral camera or a hyperspectral camera that can image light of a plurality of wavelengths.

[0054] FIG. 6 is a flowchart showing an example of the processing of the control unit 12 in the second weather observation. FIG. 7 is a flowchart showing another example of the processing of the control unit 12 in the second weather observation. The flowchart shown in FIG. 6 corresponds to the first method described above, and the flowchart shown in FIG. 7 corresponds to the second method described above.

[0055] Referring to FIG. 6, in the second weather observation, the control unit 12 controls the phased array antenna 11 to scan the entire second area R2 at high speed, thereby identifying the precipitation area and the non-precipitation area (step 101). Next, the control unit 12 controls the phased array antenna 11 to perform adaptive scanning, skipping the non-precipitation area and scanning the precipitation area. Note that, in one second weather observation (period t2), steps 101 to 102 may be repeatedly executed a plurality of times. In this case, in the second and subsequent rounds, the control unit 12 may predict the short-term movement of the cloud and identify the precipitation area and the non-precipitation area instead of step 101.

[0056] Referring to FIG. 7, in the second weather observation, the control unit 12 acquires an image of the entire second area R2 from the imaging device (step 201). Next, the control unit 12 identifies the precipitation area and the non-precipitation area based on the image (step 202). Next, the control unit 12 controls the phased array antenna 11 to perform adaptive scanning, skipping the non-precipitation area and scanning the precipitation area (step 203). Note that, in one second weather observation (period t2), steps 201 to 203 may be repeatedly executed a plurality of times.

[0057] (Weather information processing unit 14) Referring to FIG. 1 again. The weather information processing unit 14 acquires the observation information obtained by the first weather observation and the observation information obtained by the second weather observation from the radar unit 13, and processes these observation information to infer the current or future weather situation.

[0058] Here, data processing includes (1) correcting the observation information using the aircraft-mounted weather radar 10 itself or other devices, (2) calculating physical quantities based on the observation information, (3) inferring future weather situations, and so on.

[0059] Specifically, for (1), by constantly grasping the ground speed due to reflection from the ground surface, the influence of the movement of the aircraft 1 is removed from the Doppler speed and the Doppler speed width.

[0060] For (2), calculating the precipitation amount empirically from the radar reflectivity factor and the differential phase between specific polarizations, calculating the wind direction and wind speed from the spatial distribution of the Doppler speed by inverse problem solution, etc., and discriminating precipitation particles by machine learning, etc. from the reflectivity factor difference, the correlation coefficient between polarizations, the differential phase between specific polarizations, etc. For (3), it can be realized by time extrapolation of observation information using an autoregressive model or assimilation to a weather model. These processes may be performed in consideration of the overall weather situation on the ground obtained from the external device 20 via the communication unit 17.

[0061] (Current weather display unit 15) The current weather display unit 15 displays the current weather situation inferred by the weather information processing unit 14.

[0062] (Predicted weather display unit 16) The predicted weather display unit 15 displays the future weather situation inferred by the weather information processing unit 14.

[0063] (Communication unit 17) The communication unit 17 transmits the current or future weather situation (related information) based on the first weather observation and the second weather observation, inferred by the weather information processing unit 14, to the external device 20. Note that the communication unit 17 may directly transmit the observation information obtained by the first weather observation and the observation information obtained by the second weather observation (related information) to the external device 20. In this case, the data processing in (1) to (3) above may be executed on the external device 20 side.

[0064] Note that in the example here, the case where both the information based on the first weather observation and the information based on the second weather observation are transmitted from the aircraft 1 to the external device 20 has been described. On the other hand, only the information based on the second weather information among these can also be transmitted to the external device 20.

[0065] [External device 20] The external device 20 includes a weather information processing unit 24, a current weather display unit 25, a predicted weather display unit 26, and a communication unit 27.

[0066] (Weather information processing unit 24) The weather information processing unit 24 infers the overall current or future weather situation on the ground based on both the observation information received from each weather observation device 30 (such as a ground-mounted weather radar) and the weather situation information received from each aircraft 1.

[0067] 1. Inference of the current weather situation For example, there may be a case where the observation area of the meteorological observation device 30 overlaps with the observation area by the aircraft 1. In this case, the meteorological information processing unit 24 can improve the estimation accuracy of the meteorological situation by combining the two by means of maximum likelihood estimation or the like.

[0068] Also, for example, the aircraft 1 may fly over an unobserved area (e.g., the sea) of the meteorological observation device 30. In this case, based on the meteorological situation information from the aircraft 1, the meteorological situation of the unobserved area can be filled in. Note that the information on the unobserved area of the meteorological observation device 30 can also be transmitted in advance from the external device 20 side to the aircraft 1 side, and the second meteorological observation can be performed only when the aircraft 1 enters the unobserved area.

[0069] Note that the meteorological observation device 30 can also be omitted. In this case, it becomes possible to take measures against the weather for the first time based on the observation information received from each aircraft 1.

[0070] 2. Estimation of Future Meteorological Situation By using both the observation information from the meteorological observation device 30 and the meteorological situation information from each aircraft 1, a meteorological situation with high accuracy and few unobserved areas can be obtained. Therefore, the meteorological information processing unit 24 can perform time extrapolation using, for example, an autoregressive model on this meteorological situation with high accuracy and few unobserved areas, enabling the estimation of future meteorological situations with high accuracy.

[0071] Also, by assimilating the meteorological situation information from the aircraft 1 into the meteorological model, meteorological prediction can be performed (when there is no meteorological observation device 30), or the accuracy of meteorological prediction can be improved (when there is a meteorological observation device 30).

[0072] (Current Meteorological Display Unit 25) The current meteorological display unit 25 displays the current meteorological situation estimated by the meteorological information processing unit 24.

[0073] (Predicted Meteorological Display Unit 26) The predicted meteorological display unit 26 displays the future meteorological situation estimated by the meteorological information processing unit 24. (Communication Unit 27)

[0074] The communication unit 27 transmits to each aircraft 1 the overall current or future weather situation on the ground inferred by the weather information processing unit 24. Further, the communication unit 27 receives observation information from the weather observation device 30. Note that the communication unit 27 may transmit the observation information from the weather observation device 30 to each aircraft 1 as it is.

[0075] <Function, etc.> As described above, in the present embodiment, the aircraft-mounted weather radar 10 performs the first weather observation and the second weather observation. Thereby, it is possible to achieve both the weather observation for the safe flight of the aircraft 1 and the weather observation for reinforcing the weather observation, improving the weather prediction, etc.

[0076] Further, in the present embodiment, since the first weather observation and the second weather observation are realized by a single weather radar (radar unit 13), it is possible to reduce costs, weight, and size. Further, since adaptive scanning is performed in the second weather observation, the period t2 of the second weather observation can be shortened. Therefore, the second weather observation can be performed while maintaining the flight safety of the aircraft 1.

[0077] Here, weather prediction is utilized in a very wide range of fields, and it can be said that the economic effect due to its improvement is extremely high. High-speed scanning technologies such as adaptive scanning and angle imaging described later have not been realized in the aircraft-mounted weather radar 10 so far, but have been sufficiently studied and put into practical use in ground-based weather radars in the last about 20 years.

[0078] In addition, it is considered that there are no difficulties specific to the platform of the aircraft 1. Regarding the communication technology connecting the in-flight and the ground, standardization in the aviation industry is insufficient, and the level of technology in use is generally extremely low compared to others. This problem is considered to be a bottleneck in industrializing this technology. However, since the communication technology itself is sufficiently developed and the need to promote standardization is shared in the aviation industry, there is a high possibility of resolving it early.

[0079] <<Second Embodiment>> Next, the second embodiment of this technology will be described. In the above-described first embodiment, the case where the first weather observation and the second weather observation are alternately repeated in a time-division manner was described. On the other hand, in the second embodiment, the first weather observation and the second weather observation are executed simultaneously in parallel.

[0080] Typically, in the second embodiment, the control unit 12 controls the phased array antenna 11 to execute angle imaging, thereby performing simultaneous observation of the first region R1 and the second region R2.

[0081] Angle imaging will be described. The phased array antenna 11 can form various antenna directivities. Utilizing this feature, angle imaging is to simultaneously observe a plurality of directions. By this angle imaging, the first weather observation and the second weather observation can be performed simultaneously.

[0082] FIG. 8 is a side view showing a state when the first weather observation and the second weather observation are simultaneously performed by angle imaging. In angle imaging, electromagnetic waves are simultaneously irradiated in a plurality of directions, and scattered signals from the precipitation area are received. The received scattered signal is a signal in which scattered signals from all directions irradiated with electromagnetic waves are mixed, and digital beamforming is used to separately acquire each scattered signal. Note that the angle imaging technology is disclosed in Non-Patent Documents 4 and 5 above.

[0083] In the second embodiment, since the first weather observation and the second weather observation are performed simultaneously and in parallel, the safety of the flight by the aircraft 1 is not impaired.

[0084] <<Others>> Adaptive scanning and angle imaging can be used in combination, whereby the advantages of both (short-time observation and simultaneous observation in multiple directions) can be enjoyed simultaneously. That is, by using both in combination, after specifying the direction in which the precipitation area exists, it is possible to simultaneously observe a plurality of directions in which the precipitation area exists. Furthermore, since the first weather observation and the second weather observation are performed simultaneously and in parallel, the safety of the flight by the aircraft 1 is not impaired.

Explanation of Reference Numerals

[0085] 1... Aircraft 10... Aircraft-mounted weather radar 11... Phased antenna 12... Control unit 13... Radar unit 20... External device 30... Weather observation device 100... Weather observation system

Claims

1. A phased array antenna, a first weather observation for observing the weather in a first area including the traveling direction of the aircraft by the phased array antenna, and a second weather observation for observing the weather in a second area different from the first area by the phased array antenna, and a control unit that alternately repeats the first weather observation and the second weather observation in a time-division manner, the period in the second weather observation is shorter than the period in the first weather observation, in the second weather observation, the control unit controls the phased array antenna to perform an adaptive scan, thereby skipping a non-specific area and scanning a specific area in the second area An aircraft-mounted weather radar.

2. The aircraft-mounted weather radar according to claim 1, in the second weather observation, the control unit identifies the specific area and the non-specific area in the second area before the adaptive scan, An aircraft-mounted weather radar.

3. The aircraft-mounted weather radar according to claim 2, the control unit identifies the specific area and the non-specific area by scanning the entire second area with the phased array antenna, An aircraft-mounted weather radar.

4. The aircraft-mounted weather radar according to claim 2, further comprising an imaging device for imaging the entire second area, the control unit identifies the specific area and the non-specific area based on the image information from the imaging device, An aircraft-mounted weather radar.

5. The aircraft-mounted weather radar according to any one of claims 1 to 4, the specific area is a precipitation area, and the non-specific area is a non-precipitation area An aircraft-mounted weather radar.

6. An aircraft-mounted weather radar according to any one of claims 1 to 5, wherein the second area is wider than the first area Aircraft-mounted weather radar.

7. An aircraft-mounted weather radar according to any one of claims 1 to 6, further comprising a weather information processing unit that estimates the weather situation based on the first weather information and the information obtained from the second weather observation Aircraft-mounted weather radar.

8. An aircraft-mounted weather radar according to any one of claims 1 to 7, further comprising a communication unit that transmits the relevant information to an external device that receives and collects the relevant information related to at least the information obtained from the second weather observation among the first weather observation or the second weather observation from each aircraft Aircraft-mounted weather radar.

9. An aircraft-mounted weather radar according to claim 8, wherein the external device estimates the overall weather situation on the ground based on the relevant information from each aircraft Aircraft-mounted weather radar.

10. A phased array antenna, a first weather observation for observing the weather in a first area including the traveling direction of the aircraft by the phased array antenna, and a second weather observation for observing the weather in a second area different from the first area by the phased array antenna, and a control unit that alternately repeats the first and second weather observations in a time-division manner, wherein the period in the second weather observation is shorter than the period in the first weather observation, and in the second weather observation, the control unit controls the phased array antenna to perform an adaptive scan to skip a non-specific area and scan a specific area in the second area Aircraft-mounted weather radar An aircraft comprising

11. A phased array antenna, a first weather observation for observing the weather in a first area including the traveling direction of the aircraft by the phased array antenna, and a second weather observation for observing the weather in a second area different from the first area by the phased array antenna, and a control unit that alternately repeats the first weather observation and the second weather observation in a time-division manner, the period in the second weather observation is shorter than the period in the first weather observation, the control unit controls the phased array antenna to perform an adaptive scan in the second weather observation, thereby skipping a non-specific area and scanning a specific area in the second area a plurality of aircraft equipped with aircraft-mounted weather radars, an external device that receives and collects relevant information related to the information obtained at least in the second weather observation among the first weather observation or the second weather observation from each of the aircraft A weather observation system comprising

Images