Method and system for measuring state of ionosphere and troposphere
The system on an aircraft with GNSS and IMU equipment allows precise measurement of ionospheric and tropospheric conditions over oceans and hard-to-reach areas, enhancing communication and weather forecasting accuracy.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ANA HOLDINGS
- Filing Date
- 2026-01-16
- Publication Date
- 2026-07-23
Smart Images
Figure JP2026001287_23072026_PF_FP_ABST
Abstract
Description
Method for Measuring Ionospheric and Tropospheric Conditions and Measurement System Thereof Cross - Reference to Related Applications
[0001] This application is based on Japanese Patent Application No. 2025 - 6223 filed on January 16, 2025, the contents of which are incorporated herein by reference.
[0002] This disclosure relates to a method for measuring ionospheric and tropospheric conditions and a measurement system therefor. In particular, it relates to a method for measuring an index of ionospheric conditions and the amount of water vapor.
[0003] In this application, "ionospheric conditions" means the electron density and S4 which are indices of ionospheric conditions, and the measurement of ionospheric conditions is defined to mean the measurement of the electron density and S4 which are indices of ionospheric conditions. Also, in this application, tropospheric conditions are defined to mean water vapor as an index of tropospheric conditions, and the measurement of tropospheric conditions is defined to mean the measurement of the amount of water vapor as an index of tropospheric conditions. And, the airspace above the sea is defined as the space from a point where the latitude and longitude are in the ocean to the height of the ionosphere. In the measurement of ionospheric and tropospheric conditions using remote sensing, it is measured by receiving radio waves transmitted from a transmitter with a receiver. The ionospheric and tropospheric conditions between the transmitter and the receiver are measured in the radio wave reception state, and it is defined as the measured value of the ionospheric and tropospheric conditions at the position of the receiver. Therefore, in the measurement of ionospheric and tropospheric conditions, accurate measurement of the respective positions of the transmitter and the receiver is required.
[0004] Japanese Patent Application Laid - Open No. 2007 - 127502
[0005] For example, as disclosed in Patent Document 1, in the conventional measurement of ionospheric or tropospheric conditions by remote sensing, the transmitter is an artificial satellite capable of transmitting radio waves from outside the ionosphere, and the receiver is a terrestrial base station that can be fixedly installed at an accurate position and whose position can be used as a fixed value. Therefore, the measurement of ionospheric and tropospheric conditions over land has been sufficiently made.
[0006] On the other hand, it is difficult to permanently place receivers on the sea, and to place them over a wide area. Since receivers cannot be installed on the sea, it is impossible to measure the ionospheric and tropospheric conditions above the ocean. Approximately 70% of the Earth is covered by ocean, and the ionospheric and tropospheric conditions above the ocean have various significant impacts on our lives. Furthermore, it is difficult to permanently place receivers in difficult-to-reach locations on land, such as mountains and deserts.
[0007] For example, the lack of data on the ionospheric state above the ocean is detrimental to improving communication accuracy, such as intercontinental communications, and limits the accuracy of space weather forecasts, making it difficult to elucidate the mechanisms of various phenomena in the ionosphere. Furthermore, meteorological conditions that adversely affect land, such as the formation of typhoons and linear rainbands, are caused by the flow of water vapor, and the source of this is the amount of water vapor above the ocean. The lack of data on the tropospheric state above the ocean leads to inaccurate typhoon path predictions and makes it difficult to predict the formation of linear rainbands.
[0008] One possible approach to this is to mount a receiver on a moving object on the sea and perform measurements. However, when using a moving object, it is necessary to accurately determine the position of the object at each measurement point. For example, one possible method is to mount a receiver on an aircraft to acquire observational data on the ionospheric and tropospheric conditions above the sea.
[0009] In this case, the aircraft's position at each measurement point is accurately determined by equipping it with an Inertial Navigation Unit (IMU). However, even if an IMU is mounted on the aircraft to perform measurements, it is necessary to use a land-based base station to accurately determine its position, and observations of ionospheric and tropospheric conditions over the sea by aircraft have been limited to areas close to land. As a result, observational data on ionospheric and tropospheric conditions over wide ocean areas such as the Pacific and Atlantic Oceans have not been obtained. It is desirable to be able to observe ionospheric and tropospheric conditions over difficult-to-access areas on land or at sea without relying on measurements at land-based base stations. If ionospheric and tropospheric conditions can be observed without relying on measurements at land-based base stations, it would be advantageous as it would be possible to obtain observational data not only over the sea but also over difficult-to-access areas on land such as deserts and mountainous regions, where it was previously difficult to install receivers.
[0010] A state measurement system according to one aspect of the present disclosure includes an ionospheric-tropospheric measurement device mounted on an aircraft that receives positioning signals including radio waves in at least two frequency bands from a positioning satellite and acquires predetermined measurement data, and a ground support device that measures the state of at least one of the ionosphere and the troposphere based on the measurement data received from the ionospheric-tropospheric measurement device and the aircraft's position data received from the aircraft.
[0011] An ionospheric and tropospheric state measurement system according to one aspect of the present disclosure comprises: an artificial satellite capable of transmitting radio waves in at least two frequency bands and capable of positioning; an aircraft equipped with a GNSS receiver and an IMU as part of a control system, the aircraft equipped with a memory device for storing the aircraft's position data acquired by the GNSS receiver and the IMU; and an ionospheric and tropospheric measurement device mounted on the aircraft, communicatively connected to the GNSS receiver and the IMU and capable of receiving the radio waves, wherein the system receives the radio waves in at least two frequency bands, the ionospheric and tropospheric measurement device acquires the aircraft's position data at the time of the reception of the radio waves from the aircraft's memory device, the ionospheric and tropospheric measurement device associates the radio wave signals with the position of the measurement point and stores it in the memory device of the ionospheric and tropospheric measurement device.
[0012] A method for measuring the ionosphere and troposphere state according to one aspect of the present disclosure is a measurement method for measuring the ionosphere and troposphere state using an ionosphere and troposphere state measurement system comprising: an artificial satellite capable of transmitting radio waves in at least two frequency bands and capable of positioning; an aircraft equipped with a GNSS receiver and an IMU as part of a control system, the aircraft equipped with a memory device for storing the aircraft's position data acquired by the GNSS receiver and the IMU; and an ionosphere and troposphere measuring device mounted on the aircraft, communicated with the GNSS receiver and the IMU, and capable of receiving the radio waves, the method comprising the steps of: receiving the radio waves in at least two frequency bands with the ionosphere and troposphere measuring device, acquiring the aircraft's position data at the time the ionosphere and troposphere measuring device received the radio waves from the aircraft's memory device; and associating the radio wave signals with the position of the measurement point and storing it in the memory device of the ionosphere and troposphere measuring device.
[0013] According to this disclosure, ionospheric and tropospheric conditions can be observed in the upper atmosphere using radio waves from positioning satellites.
[0014] This is a conceptual diagram of the ionosphere and tropospheric state measurement system 1 in one embodiment of the present invention. This is a system configuration another embodiment of the ionosphere and tropospheric state measurement system 1 in one embodiment of the present invention. This is a conceptual diagram of the system of the ionosphere and tropospheric state measurement system 1 during ionosphere state measurement in one embodiment of the present invention, and a conceptual diagram of ionosphere state measurement. This is a conceptual diagram of the system of the ionosphere and tropospheric state measurement system 1 during tropospheric state measurement in one embodiment of the present invention. This is a conceptual diagram of tropospheric state measurement in one embodiment of the present invention. This is a conceptual diagram of tropospheric state measurement near land in one embodiment of the present invention. This is a conceptual diagram showing the measurement results at measurement points of the ionosphere and tropospheric state measurement system as the Earth's surface. This is a conceptual diagram showing the measurement results along a route composed of consecutive data points selected from Figure 4A.
[0015] An embodiment of the ionospheric and tropospheric state measurement method and ionospheric and tropospheric state measurement system 1 of the present invention will be described with reference to Figures 1A to 1E. Figure 1A is a conceptual diagram of the ionospheric and tropospheric state measurement system 1 of the present invention. Figure 1B is a system configuration diagram of the ionospheric and tropospheric state measurement system 1 of the present invention. Figure 1C is a system configuration diagram of another embodiment of the ionospheric and tropospheric state measurement system 1 of the present invention. Figure 1D is a conceptual diagram of the system of the ionospheric and tropospheric state measurement system 1 during ionospheric state measurement of the present invention. Figure 1E is a conceptual diagram of the system of the ionospheric and tropospheric state measurement system 1 during tropospheric state measurement of the present invention.
[0016] <Method and System Configuration for Measuring the State of the Ionosphere and Troposphere> The ionosphere and troposphere state measurement system 1, which measures the state of the ionosphere and troposphere, comprises an aircraft 2, a positioning-capable artificial satellite 3, and ground support equipment 5. The aircraft 2 is preferably one with a flight range of at least 2000 kilometers in order to observe a wide area in a short time. The ionosphere and troposphere state measurement system 1 comprises an aircraft 2, an artificial satellite 3, an ionosphere and troposphere measurement device 4 mounted on the aircraft 2, and ground support equipment 5.
[0017] As shown in Figure 1B, the aircraft 2 in the ionospheric and tropospheric state measurement system 1 is defined as an aircraft equipped with a GNSS receiver 21, an IMU 22, and a memory device 23 as part of the aircraft's control system 2a. The GNSS receiver 21 and IMU 22 are pre-installed during the manufacture of the aircraft 2 and are electrically connected to the devices constituting the aircraft's control system 2a. The GNSS receiver 21 is a device that receives positioning signals from satellite positioning systems (GNSS (Global Navigation Satellite System)) such as GPS and QZSS, and can calculate and define the position and attitude of the aircraft 2. The GNSS receiver 21 and IMU 22 may be separate or integrated. In other words, aircraft 2 stores the aircraft's position, measured by the GNSS receiver 21 and IMU 22, as position data in the memory device 23, and uses the position data of aircraft 2 acquired by the GNSS receiver 21 and IMU 22 for autopilot and other equipment necessary for flight. In particular, in order to enable constant fixed-point observation, it is preferable that aircraft 2 is an airline that operates regularly on the same route (i.e., a scheduled airline).
[0018] Satellite 3 consists of at least three satellites 31, 32, and 33. Satellite 3 is a general category of positioning satellites such as GNSS, including, for example, GPS and QZSS. Aircraft 2 measures GNSS data based on signals received from satellite 3 (31, 32, and 33) that are in a position convenient for measurement.
[0019] The ionospheric-tropospheric measurement device 4 is equipped with an antenna 4a and is capable of receiving positioning signals that include radio waves in at least two frequency bands transmitted by artificial satellites 3 (31, 32, 33) (typically L1 band waves (center frequency 1575.42 MHz) and L2 band waves (center frequency 1227.60 MHz) or L1 band waves and L5 band waves (center frequency 1176.45 MHz)), and acquiring various measurement data (hereinafter also referred to as "GNSS data") based on the received signals. The position of the antenna 4a is mounted at a location corresponding to the aircraft 2. Typically, the ionospheric-tropospheric measurement device 4 is equipped with a memory device 41 that stores the acquired measurement data. The measurement data includes, but is not limited to, the propagation delay amount or Doppler delay amount of the radio waves in the two frequency bands received by the ionospheric-tropospheric measurement device 4. The memory device 41 may be an external device of the ionospheric-tropospheric measurement device 4. Below, we will explain two representative frequency bands of radio waves, using L1 band waves (center frequency 1575.42 MHz) and L2 band waves (center frequency 1227.60 MHz), or L1 band waves and L5 band waves (center frequency 1176.45 MHz), as examples.
[0020] The ionospheric and tropospheric measuring device 4 can measure the propagation delay of two frequencies of radio waves emitted by the artificial satellite 3, namely L1 band waves and L2 band waves, or the propagation delay of two frequencies of radio waves emitted by the artificial satellite 3, namely L1 band waves and L5 band waves. Furthermore, it can store the signals of radio waves in two frequency bands, namely L1 band waves and L2 band waves, or L1 band waves and L5 band waves, emitted from the artificial satellite 3, in the memory device 41. Alternatively, it can be transmitted to the ground support device 5 and stored in the memory device 5a of the ground support device 5.
[0021] The ionospheric-tropospheric measurement device 4 is connected by wire or wireless to a memory device 23 that stores the position data of aircraft 2 from the IMU 22 of aircraft 2, and may be able to acquire the position data of aircraft 2 from the memory device 23 according to the passage of time (change in the position of latitude and longitude) of aircraft 2. The ionospheric-tropospheric measurement device 4 stores the propagation delay amount of L1 band and L2 band or L1 band and L5 band radio waves, and the Doppler delay amount of L1 band and L2 band or L1 band and L5 band radio waves, as data associated with the position data of aircraft 2 acquired from the memory device 23 at the location where each was acquired, in the memory device 41. Alternatively, it is transmitted to the ground support device 5 and stored in the memory device 5a of the ground support device 5. In this embodiment, the association between the GNSS data measured by the ionospheric-tropospheric measurement device 4 and the position data of aircraft 2 measured by the control system 2a is described as being performed within aircraft 2, but this association does not need to be performed within aircraft 2. GNSS data and position data may be transmitted separately from the aircraft 2 to the ground support device 5, and the ground support device 5 may then associate them.
[0022] The ground support device 5 is capable of communicating with the ionospheric-tropospheric measuring device 4 mounted on the aircraft 2, and measures the state of at least one of the ionosphere and troposphere from signal data received from the ionospheric-tropospheric measuring device 4. As an example, the ground support device 5 calculates the total number of electrons and S4 (amplitude scintillation index) as indicators of the ionospheric state, and the amount of water vapor as an indicator of the tropospheric state. The ground support device 5 in the ionospheric and tropospheric state measurement system 1 may not have a measurement function and may not measure the position of the aircraft 2 performing the measurement or the state of the ionosphere and troposphere.
[0023] The ground support device 5 uses signal data received from the ionospheric-tropospheric measurement device 4 to obtain ionospheric state data at any latitude and longitude, including over the sea, including the distribution of electron quantity (distribution of total electron index (TECU)) and S4 (distribution of scintillation (microsieverts / h)) and tropospheric state data, including water vapor quantity (g / m³). ３The calculation is performed and stored in the memory device 5a. The memory device 5a may be part of the internal devices of the ground support system 5, or it may be an external device of the ground support system 5.
[0024] These distributions correspond to the flight paths of aircraft 2 and naturally include ionospheric and tropospheric state data over the sea and over treacherous areas on land. Next, the method for measuring the ionospheric and tropospheric states using the ionospheric and tropospheric state measurement system 1 will be described.
[0025] <Method for determining the position of aircraft 2> The flight position (latitude and longitude) of aircraft 2 is measured by the GNSS receiver 21 and IMU 22 through communication with positioning-capable artificial satellites 3. The positioning method is not particularly limited, and measurement may be performed by measurement corresponding to the positioning-capable artificial satellites 3. The flight position (latitude and longitude) of aircraft 2 measured by artificial satellites 3 is received and defined by the GNSS receiver 21 and IMU 22 of aircraft 2. The position of aircraft 2 received by the GNSS receiver 21 and IMU 22 is defined as position data of aircraft 2, and at the time of measurement of the ionospheric state and the tropospheric state, the ionospheric-tropospheric measurement device 4 acquires the position data of aircraft 2 at the time of measurement (measurement point) from the GNSS receiver 21 and IMU 22 or the memory device 23 in which the position data is stored. It is preferable to always perform positioning of aircraft 2 while performing the measurement of the ionospheric state and the tropospheric state of the present invention.
[0026] Furthermore, as shown in Figure 1C, the ionospheric and tropospheric state measurement system 1 may also be equipped with a second GNSS receiver 212 and a second inertial navigation system (hereinafter referred to as "second IMU") 222, which are not connected to the devices constituting the aircraft's control system and are not used for autopilot or other maneuvers during flight, as auxiliary equipment.
[0027] The second GNSS receiver 212 and the second IMU 222 may be placed separately from the ionospheric-tropospheric measuring device 4 at any suitable location inside the aircraft 2, as shown in Figure 1C, or they may be built in as part of the ionospheric-tropospheric measuring device 4, although this is not shown in the figure. The first IMU 221 and the second IMU 222 are connected to the ionospheric-tropospheric measuring device 4 so that aircraft position data can be acquired from the first GNSS receiver 211 and the first IMU 221, and from the second GNSS receiver 212 and the second IMU 222, respectively. The data from the first GNSS receiver 211 and the first IMU 221, as well as the data from the second GNSS receiver 212 and the second IMU 222, are both sent from the ionospheric-tropospheric measuring device 4 to the ground support device 5, associated with ionospheric state measurement data and tropospheric state measurement data.
[0028] As a result, by additionally using the second GNSS receiver 212 and the second IMU 222 in addition to the position data of the aircraft 2 obtained by the first GNSS receiver 211 and the first IMU 221, the performance of the measurement data of the aircraft 2's position (measurement point) can be improved. Even when the second GNSS receiver 212 and the second IMU 222 are additionally used in addition to the first GNSS receiver 211 and the first IMU 221, the ionospheric-tropospheric measurement device 4 acquires the position data of the aircraft 2 from the first GNSS receiver 211 and the first IMU 221 and the second GNSS receiver 212 and the second IMU 222 in accordance with the timing of the measurement of the ionospheric state and the measurement of the tropospheric state. In other words, when acquiring position data of the aircraft 2 from the first GNSS receiver 211 and the first IMU 221 and the second GNSS receiver 212 and the second IMU 222, this is also one embodiment of acquiring position data of the aircraft 2 from the GNSS receiver 21 and IMU 22 of the control system 2a.
[0029] Therefore, in the description herein, even when the first GNSS receiver 211 and the first IMU 221 and the second GNSS receiver 212 and the second IMU 222 are arranged, the ionospheric-tropospheric measuring device 4 will be described as acquiring the position data of the aircraft 2 from the GNSS receiver 21 and IMU 22 of the control system 2a. This is understood to refer to both the case where only the GNSS receiver 21 and IMU 22 are present (Figure 1B) and the case where the first GNSS receiver 211 and the first IMU 221 and the second GNSS receiver 212 and the second IMU 222 are mounted as the GNSS receiver 21 and IMU 22 (Figure 1C).
[0030] <Method for Measuring Ionospheric State by Aircraft 2> Next, the measurement of the ionospheric state by aircraft 2 will be explained with reference to Figure 1D. The measurement of the ionospheric state is defined as measuring the "total electron count" and "S4". The ionospheric-tropospheric measuring device 4 measures the ionospheric state from the Earth's surface to the outermost layer of the ionosphere (approximately 400 kilometers). As shown in Figure 1D, first, among the artificial satellites 3, artificial satellites 32 and 33 that are in a position that does not disappear from the view of aircraft 2 (including above the aircraft) and are not cast by the Earth's shadow due to orbiting the Earth are selected as communication targets for measurement. Among the artificial satellites 3, artificial satellite 31 that is in a position that disappears from the view of aircraft 2 is not used for measuring the ionospheric state. Artificial satellite 31 that is in a position that disappears from the view of aircraft 2 is an artificial satellite 31 located in the direction of the view direction HV of aircraft 2 and below it, when the horizontal direction of aircraft 2 is defined as the view direction HV of aircraft 2. Aircraft 2 receives radio waves in two frequency bands, L1 band and L2 band, or L1 band and L5 band, from artificial satellites 32 and 33, which are located within the aircraft's field of view, at predetermined intervals or distances. The predetermined interval is, for example, every 2 seconds, and the predetermined distance is, for example, every 3000 km.
[0031] The ionospheric-tropospheric measuring device 4 associates the measurement signals of two frequency bands of radio waves, L1 band and L2 band, or L1 band and L5 band, with the position data of the measurement point and stores them in the memory device 41 of the ionospheric-tropospheric measuring device 4. Alternatively, the ionospheric-tropospheric measuring device 4 calculates the propagation delay amount of two frequencies from the received measurement signals of L1 band and L2 band or L1 band and L5 band. The calculated propagation delay amount of two frequencies is associated with the position data of the measurement point and stored in the memory device 41 of the ionospheric-tropospheric measuring device 4. Alternatively, the measured propagation delay amount data of two frequencies is corrected considering the speed of movement of the artificial satellites 31, 32 or 33 and the aircraft 2, the corrected value is taken as the true value of the propagation delay amount of two frequencies at the measurement point, it is associated with the position data of the measurement point, and stored in the memory device 41 located in the ionospheric-tropospheric measuring device 4 of the aircraft 2. The position data of the measurement point is typically the position of aircraft 2, and the position data of aircraft 2 is obtained from the aircraft 2's memory device 23 (as supplementary information, if a second GNSS receiver 212 and a second IMU 222 are provided in addition to the first GNSS receiver 211 and the first IMU 221, the position data of aircraft 2 is obtained from the second GNSS receiver 212 and the second IMU 222).
[0032] Furthermore, in the measurement of the ionospheric state by aircraft 2, the "total number of electrons" and "S4" are measured at a point between satellite 3 and aircraft 2. Therefore, the measurement point for the "total number of electrons" and "S4" determined by the propagation delay of two frequencies can be defined as a point between satellite 3 and aircraft 2, and is defined as the "total number of electrons" and "S4" at a representative point between aircraft 2 and satellite 3. The representative point (representative position data) between aircraft 2 (point A in Figure 1D) and satellite 3 (point B in Figure 1D) can also be defined as any point D between aircraft 2 (aircraft point A in Figure 1D) and the outermost layer of the ionosphere, by considering the intersection point C of the imaginary line connecting aircraft 2 (aircraft point A in Figure 1D) and satellite 3 (satellite position point B in Figure 1D) and the outermost layer of the ionosphere, and defining the representative position data of the measurement point as the measurement point. An arbitrary point D can also be defined as the midpoint between aircraft 2 (point A in Figure 1D) and the intersection point C with the outermost layer of the ionosphere, and this can be defined as representative position data corresponding to the measurement point. This means that the "total number of electrons" and "S4" between aircraft point A and intersection point C are defined as the "total number of electrons" and "S4" at point D, with point D as the representative position data. The position data of aircraft 2 here is determined as the position data of aircraft 2 acquired by the ionospheric-tropospheric measurement device 4 from the IMU 22 at the time of measurement, according to the positioning method of aircraft 2. The position of the artificial satellite 3 is obtained separately by the ground support device 5 (as supplementary information, here as well, if a second GNSS receiver 212 and a second IMU 222 are provided in addition to the first GNSS receiver 211 and the first IMU 221, the position data of aircraft 2 will be obtained from the second GNSS receiver 212 and the second IMU 222).
[0033] The ionospheric-tropospheric measurement device 4, in response to the received measurement signals of L1 band waves and L2 band waves or L1 band waves and L5 band waves, acquires the position data of aircraft 2 from the IMU 22 at that time and associates them. The ionospheric-tropospheric measurement device 4 on aircraft 2 transmits data on the propagation delay amounts of the two ionospheric frequencies at the measurement point to the ground support device 5, and the ground support device 5 receives the data on the propagation delay amounts of the two frequencies at the measurement point sent from aircraft 2.
[0034] The ground support device 5 repeats these operations along the flight path of aircraft 2, from the time aircraft 2 moves until it stops. Similarly, these operations are repeated for other aircraft on flights controlled by the ionospheric and tropospheric state measurement system 1. The ground support device 5 then calculates the "total electron count" and "S4" in the ionosphere by converting the propagation delay amounts of the two frequencies. The propagation delay amounts of the two frequencies in the ionosphere are correlated with electron density, and various methods can be used to convert the propagation delay amounts of the two frequencies into the "total electron count" and "S4". For example, for the "total electron count," the pseudo-distance due to L2 band radio waves is subtracted from the pseudo-distance due to L1 band radio waves, leaving the ionospheric delay term and the difference in receiver and satellite-specific bias values. The carrier phase due to L2 band radio waves is then subtracted from the carrier phase due to L1 band radio waves, leaving the ionospheric propagation delay term and the difference in satellite-specific bias values. By subtracting these two terms, the ionospheric propagation delay term (propagation delay amount) is obtained. Since the propagation delay increases in proportion to the electron density, the total number of electrons can be determined from the propagation delay. Furthermore, since the total number of electrons can be considered as the electron density within a predetermined reference volume at the measurement point, scintillation represents the spatial heterogeneity of electrons, and the variance of the signal intensity change, normalized by the average signal intensity of the signal intensity defined as the total number of electrons, can be obtained as S4, an indicator of scintillation. For "total number of electrons" and "S4," the values associated with the measurement point are more important than the absolute values, and this allows for an understanding of the distribution of "total number of electrons" and "S4" when viewing the measurement points from an overview perspective. In this invention, the objective is achieved as long as the same method is used to convert the propagation delay amounts of two frequencies into "total number of electrons" and "S4." The "total number of electrons" and "S4" at any measurement point are defined using this method and stored in the memory device 5a.
[0035] It is not necessary for the ground support device 5 to convert the true values of the propagation delay amounts of the two frequencies into "total electron count" and "S4" for calculation. The ionospheric-tropospheric measurement device 4 may also convert the true values of the propagation delay amounts of the two frequencies into "total electron count" and "S4" for calculation. In this case, the ionospheric-tropospheric measurement device 4 defines the "total electron count" and "S4" at any measurement point and transmits this to the ground support device 5. The ground support device 5 then stores the "total electron count" and "S4" at any measurement point in the memory device 5a.
[0036] <Method for Measuring Tropospheric Conditions by an Aircraft> (Measurement during Takeoff and Landing of Aircraft 2) Next, the measurement of tropospheric conditions by aircraft 2 will be explained with reference to Figures 1E and 2, and Figures 1E and 3. The troposphere extends from the Earth's surface to an altitude of approximately 10 kilometers. Therefore, aircraft 2 is located in the troposphere during takeoff and landing (close to land), but flies near the outermost layer of the troposphere and the innermost layer of the ionosphere during level flight (far from land). For this reason, tropospheric measurements are performed in two parts: measurements during takeoff and landing of aircraft 2 (close to land) and measurements during level flight of aircraft 2 (far from land). First, the measurement of tropospheric conditions during takeoff and landing of aircraft 2 will be explained with reference to Figures 1E and 3. Measurements during takeoff and landing of aircraft 2 are, for example, as shown in the conceptual diagram in Figure 3, measurements taken from when aircraft 2 takes off from the airport until it transitions to level flight. Landing is the reverse of this, so here we will explain using takeoff as an example. As shown in Figure 1E, aircraft 2 selects from among the satellites 3 that are capable of communication (for example, 31, 32, and 33) as targets for measurement. All satellites 3 above aircraft 2 (for example, 31, 32, and 33) are targets for communication for measurement. In particular, during measurements during takeoff and landing, aircraft 2's ionospheric and tropospheric measurement device 4 receives radio waves from satellite 31 in two frequency bands, the L1 band (center frequency 1575.42 MHz) and the L2 band (1227.60 MHz), at predetermined intervals or altitudes.
[0037] First, before takeoff (at zero altitude), the aircraft 2's ionospheric-tropospheric measuring device 4 receives L1 band and L2 band signals from the satellite 3 and calculates the propagation delay of these two frequencies (zenith tropospheric delay). This is then defined as the tropospheric state measurement reference quantity Vrf. At this time, the ionospheric-tropospheric measuring device 4 acquires the position data of the aircraft 2 at the time of measurement from the IMU 22, and stores the acquired tropospheric state measurement reference quantity Vrf and the position data of the aircraft 2 at the time of measurement in the memory device 41, associating them.
[0038] Next, after the aircraft 2 takes off, at 1 × h (where h is a predetermined altitude), the ionospheric and tropospheric measuring device 4 of the aircraft 2 receives L1 band and L2 band signals from the satellite 3, calculates the propagation delay of these two frequencies, and defines this as the integrated water vapor amount M(1). Then, the ionospheric and tropospheric measuring device 4 acquires the position data of the aircraft 2 at the time of measurement from the IMU 22, associates the acquired integrated water vapor amount M(1) with the position data of the aircraft 2 at the time of measurement, and stores it in the memory device 41.
[0039] Similarly, after the aircraft 2 takes off, at 2 × h (where h is a predetermined altitude), the ionospheric-tropospheric measuring device 4 of the aircraft 2 receives L1 band and L2 band signals from the satellite 3, calculates the propagation delay of these two frequencies, and defines this as the integrated water vapor amount M(2). The ionospheric-tropospheric measuring device 4 then acquires the position data of the aircraft 2 at the time of measurement from the IMU 22, associates the acquired integrated water vapor amount M(2) with the position data of the aircraft 2 at the time of measurement, and stores it in the memory device 41.
[0040] Specifically, after the aircraft 2 takes off, the ionospheric and tropospheric measuring device 4 of the aircraft 2 receives L1 band and L2 band signals from the satellite 3 at i × h (i = 1 to n), calculates the propagation delay of these two frequencies, and defines this as the integrated water vapor amount M(i). The ionospheric and tropospheric measuring device 4 then acquires the position data of the aircraft 2 at the time of measurement from the IMU 22, associates the acquired integrated water vapor amount M(i) with the position data of the aircraft 2 at the measurement time i, and stores it in the memory device 41. The predetermined time is, for example, every 20 seconds until the altitude change during takeoff and landing reaches a predetermined altitude every 150 m (corresponding to h above). The predetermined altitude is, for example, 20,000 feet (approximately 6,096 meters). The predetermined altitude can also be the altitude until the artificial satellites 3 (artificial satellites 31a, 31b, and 31c in the example of Figure 1E) located in the direction of the aircraft 2's line of sight HV and below it are detected. The cumulative water vapor amount M(i) means the cumulative water vapor amount accumulated vertically on the aircraft 2.
[0041] In calculating the integrated water vapor amount M(i) from the propagation delay amounts of two frequencies, formulas for converting this, such as the MOPS model and the Saastamoinen model, are generally already known in various ways. In converting from the propagation delay amount to the "water vapor amount", any of these methods can be used. That is, since the carrier wave includes the delay due to the ionosphere and the delay amount due to the troposphere, first, the delay amount due to the ionosphere can be obtained by the method of obtaining the total electron number described above, and by subtracting it, the delay amount due to the troposphere can be obtained. The delay due to the troposphere includes the delay amount due to dry air and the delay amount due to moist air. The delay due to dry air is estimated from the atmospheric pressure at the GNSS antenna position, and by subtracting the delay due to dry air from the total delay amount, the delay amount due to moist air can be obtained, and thereby the total water vapor amount in the moist air can be obtained. Regarding the "water vapor amount", rather than the absolute numerical value, the "water vapor amount" associated with the measurement location is important, and thereby the distribution of the "water vapor amount" when overlooking the measurement location can be grasped. In the present invention, when converting from the arrival delay amount to the "water vapor amount", as long as the same method is used, the purpose can be achieved. The "water vapor amount" at an arbitrary measurement location is defined from this method and stored in the memory device 5a.
[0042] Further, the ionosphere troposphere measurement device 4 may correct the data of the propagation delay amounts of the two measured frequencies in consideration of the speeds of the movement of the artificial satellite 31 and the movement of the aircraft 2 with respect to the integrated water vapor amount M(i). The corrected value can be stored in the memory device 41 arranged in the ionosphere troposphere measurement device 4 as the true value of the arrival delay amount at the measurement location. The aircraft 2 transmits the data of the integrated water vapor amount M(i) at the measurement location to the ground support device 5, and the ground support device 5 receives the data of the integrated water vapor amount M(i) at the measurement location from the ionosphere troposphere measurement device 4 of the aircraft 2.
[0043] The ground support device 5 calculates the surface-side water vapor amount V(i) (i = 1 to n) at each measurement point from the respective data of the integrated water vapor amount M(i) at each measurement point. The surface-side water vapor amount V(i) (i = 1 to n) is the difference between the troposphere state measurement reference amount Vrf and the integrated water vapor amount calculated from the propagation delay amount obtained from each of the radio wave signals received at predetermined times after the aircraft 2 takes off, that is, the water vapor amount in the atmosphere of a certain section. That is, at each measurement point, it is defined as V(i) (i = 1 to n) = Vrf - M(i).
[0044] In the above, the ionosphere-troposphere measurement device 4 calculates the integrated water vapor amount M(i). However, the propagation delay amounts of two frequencies of radio waves in the L1 band and the L2 band from the artificial satellite 3 received by the ionosphere-troposphere measurement device 4 at each measurement point may be stored in the memory device 41 arranged in the ionosphere-troposphere measurement device 4, and the ionosphere-troposphere measurement device 4 may transmit them to the ground support device 5 as the propagation delay amounts of the two frequencies. In this case, the ground support device 5 may calculate the integrated water vapor amount M(i) at each measurement point from the propagation delay amounts of the two frequencies at each measurement point. Then, the ground support device 5 may calculate the surface-side water vapor amount V(i) (i = 1 to n) at each measurement point from the integrated water vapor amount M(i) at each measurement point.
[0045] On the other hand, the ionosphere-troposphere measurement device 4 may calculate the integrated water vapor amount M(i) at each measurement point from the arrival delay amount at each measurement point, and further calculate the surface-side water vapor amount V(i) (i = 1 to n) at each measurement point from the integrated water vapor amount M(i) at each measurement point. In this case, the ionosphere-troposphere measurement device 4 transmits the surface-side water vapor amount V(i) (i = 1 to n) at an arbitrary measurement point to the ground support device 5. The ground support device 5 stores it in the memory device 5a as the surface-side water vapor amount V(i) at an arbitrary measurement point.
[0046] (Measurement of tropospheric conditions during horizontal flight of aircraft 2) First, the measurement of tropospheric conditions during horizontal flight of aircraft 2 will be explained with reference to Figures 1E and 2. When aircraft 2 is in horizontal flight after ascending due to takeoff, the tropospheric conditions are measured by the ionospheric-tropospheric measuring device 4 using the so-called occultation method. That is, as shown in Figure 1E, first, among the artificial satellites 3, artificial satellite 31 that is in a position where it will be obscured by the Earth's shadow due to orbiting the Earth and disappear from the aircraft 2's field of view is selected as the communication target for measurement. The artificial satellite 31 that is in a position where it will disappear from the aircraft 2's field of view is the artificial satellite 3 (artificial satellites 31a, 31b, 31c in the example of Figure 1E) that is located in the direction of the aircraft 2's field of view HV and below it, when the horizontal direction of aircraft 2 is defined as the aircraft 2's field of view HV. Aircraft 2 receives radio waves from satellite 31 at predetermined intervals or distances, either in two frequency bands, L1 band and L2 band, or in two frequency bands, L1 band and L5 band. The predetermined interval is, for example, every 2 seconds, and the predetermined distance is, for example, every 3000 km.
[0047] The ionospheric-tropospheric measuring device 4 associates the measurement signals of radio waves in two frequency bands, L1 band and L2 band, or L1 band and L5 band, with the position data of the measurement point and stores them in the memory device 41 of the ionospheric-tropospheric measuring device 4. Alternatively, the ionospheric-tropospheric measuring device 4 calculates the Doppler shift amount from the measurement signals of the received L1 band and L2 band or L1 band and L5 band. It associates the calculated Doppler shift amount with the position data of the measurement point and stores it in the memory device 41 of the ionospheric-tropospheric measuring device 4. Alternatively, it corrects the measured Doppler shift amount data considering the speed of the movement of the artificial satellite 31 and the movement of the aircraft 2, and stores the corrected value as the true value of the Doppler shift amount at the measurement point in the memory device 41 located in the ionospheric-tropospheric measuring device 4 of the aircraft 2. Alternatively, the measured Doppler shift data is corrected considering the speed of the movement of the artificial satellite 31 and the aircraft 2, the corrected value is taken as the true value of the Doppler shift at the measurement point, and this is associated with at least the position data of the measurement point and stored in the memory device 41 located in the ionospheric-tropospheric measuring device 4 of the aircraft 2. The position data of the measurement point is typically the position of the aircraft 2, and the position data of the aircraft 2 is obtained from the memory device 23 of the aircraft 2 (as a supplement, if a second GNSS receiver 212 and a second IMU 222 are provided in addition to the first GNSS receiver 211 and the first IMU 221, the position data of the aircraft 2 will be obtained from the second GNSS receiver 212 and the second IMU 222).
[0048] The position data of the measurement point is obtained by the Doppler shift amount, as the measurement of the "amount of water vapor" at the point between the satellite 3 and the aircraft 2 during horizontal flight of the aircraft 2 is performed. Therefore, the measurement point for the "amount of water vapor" is located between the satellite 3 and the aircraft 2. For this reason, a representative point for the "amount of water vapor" is defined between the aircraft 2 and the satellite 3. In other words, referring to Figure 2, the representative point (representative position data) between the aircraft 2 (point A in Figure 2) and the satellite 3 (point B in Figure 2) can be defined by considering the intersection points C and D of the imaginary line connecting the aircraft 2 (point A in Figure 2) and the satellite 3 (point B in Figure 2) with the outermost layer of the troposphere, and defining any point between intersection points C and D as the representative position data for the measurement point. In particular, point E, which is the midpoint between intersection points C and D, can be defined as the representative position data for the measurement point. This means that the integrated value of the water vapor amount between intersection C and intersection D is defined as the "water vapor amount" at point E, with point E as the representative position data. The position data of aircraft 2 here is determined as the position data of aircraft 2 acquired by the ionospheric-tropospheric measuring device 4 from the IMU 22 at the time of measurement, according to the positioning method of aircraft 2. The position of artificial satellite 3 is obtained separately by the ground support device 5.
[0049] The ionospheric-tropospheric measurement device 4, in response to the received measurement signals of L1 band waves and L2 band waves or L1 band waves and L5 band waves, acquires the position data of aircraft 2 from the IMU 22 at that time and associates them. The ionospheric-tropospheric measurement device 4 on aircraft 2 transmits data on the amount of Doppler shift of the ionosphere at the measurement point to the ground support device 5, and the ground support device 5 receives the data on the amount of Doppler shift at the measurement point sent from aircraft 2.
[0050] The ground support device 5 repeats these operations along the aircraft 2's flight path, from the moment the aircraft 2 starts moving until it stops. It also repeats these operations similarly for other aircraft on flights controlled by the ionospheric and tropospheric state measurement system 1. The ground support device 5 then calculates the "water vapor amount" by converting the true value of the Doppler shift, defines it as the "water vapor amount" at a given measurement point, and stores it in the memory device 5a.
[0051] The amount of Doppler shift in the convection zone correlates with the density of water molecules, and various formulas for converting the amount of Doppler shift to "water vapor content" using the occlusion method are already generally known. Any of these methods can be used to convert the amount of Doppler shift to "water vapor content". That is, by removing the effect of the ionosphere from the propagation delay effect due to the atmosphere (by subtracting the calculation results of ionospheric indices such as total electron content (TECU)), and by removing the physical quantity due to the change in the relative velocity of the airplane and the satellite from the carrier phase Doppler shift, the refractive index of radio waves due to the troposphere can be estimated, and the partial pressure of water vapor can be obtained by combining this with information on atmospheric temperature and pressure, thereby determining the "amount of water vapor". For "amount of water vapor", the "amount of water vapor" associated with the measurement point is more important than the absolute value, and this allows for an understanding of the distribution of "amount of water vapor" when looking at the measurement point from a bird's-eye view. In this invention, the objective is achieved as long as the same method is used to convert the amount of Doppler shift to "amount of water vapor". This method is used to determine the "amount of water vapor" at any given measurement point and store it in the memory device 5a.
[0052] The ground support device 5 repeats these operations along the flight path of the aircraft 2, from the time the aircraft 2 moves until it stops. Similarly, these operations are repeated for other aircraft on flights using the ionospheric and tropospheric state measurement system 1. The device then calculates how to convert the true value of the Doppler shift into "water vapor content".
[0053] The conversion and calculation of "total electrons," "S4," and "water vapor content" described above may be performed on the aircraft 2 by the ionospheric-tropospheric measuring device 4 using radio wave signals received from the satellite 3, and the results may be transmitted to the ground support device 5. Alternatively, the signal received by the ionospheric-tropospheric measuring device 4 from the satellite 3 may be transmitted to the ground support device 5, and the conversion and calculation process may be performed by the ground support device 5 from the received signal. Furthermore, the ionospheric-tropospheric measuring device 4 may calculate and convert up to intermediate variables in the conversion and calculation of "total electrons," "S4," and "water vapor content" from the radio wave signals received from the satellite 3, transmit the signals of these intermediate variables to the ground support device 5, and the ground support device 5 may perform the final conversion and calculation of "total electrons," "S4," and "water vapor content" from the received intermediate variables. In other words, the ionospheric-tropospheric measuring device 4 and the ground support device 5 can be set to cooperate in the conversion and calculation of "total electrons," "S4," and "water vapor content" from radio wave signals received from the satellite 3.
[0054] (Output from the Ionospheric and Tropospheric State Measurement System 1) Referring to Figures 4A and 4B, the concepts of "Total Electron Quantity" and "S4," which represent the ionospheric state, and "Water Vapor Quantity," which represents the tropospheric state, as output results calculated by the Ionospheric and Tropospheric State Measurement System 1, will be explained. Figure 4A is a conceptual diagram representing the measurement results from the Ionospheric and Tropospheric State Measurement System 1 at measurement points (points specified by latitude and longitude) indicated by data points DP (black dots) as the Earth's surface. Although only a portion of data points DP are shown in Figure 4A, all data points DP contain "Total Electron Quantity (TECU)," "S4 (μSv)," and "Water Vapor Quantity (g / m³)," which are calculated by the Ionospheric and Tropospheric State Measurement System 1. ３ ) and are associated. Figure 4B is a conceptual diagram showing each measurement result (vertical axis of each figure in Figure 4A) organized on a route (horizontal axis of Figure 4B) composed of selected consecutive data points from the measurement results in Figure 4A. Figure 4A is a conceptual diagram for ease of understanding, so the actual data points DP (black dots in Figure 4A) are much more numerous and detailed. Figure 4B is a conceptual diagram for explanatory purposes, and no specific numerical values are given to the scale of the vertical axis.
[0055] As explained above, the ionospheric and tropospheric state measurement system 1 can measure (observe) the ionospheric and tropospheric states, namely "total electrons," "S4," and "water vapor content," over difficult areas of land or sea without the need for measurements at ground base stations. Therefore, as shown in Figure 4A, the ionospheric and tropospheric state measurement system 1 can provide measured values of "total electrons," "S4," and "water vapor content" in various ways over the entire globe, including over the sea and difficult areas of land, as far as the aircraft 2 can navigate.
[0056] As shown in the diagram of the Earth in Figure 4A, the ionospheric and tropospheric state measurement system 1 uses the actual data points DP (black dots in Figure 4A), which are the measurement locations, and the "total electron content (TECU)", "S4 (μSv)", and "water vapor content (g / m³)" calculated by the ionospheric and tropospheric state measurement system 1. ３ The associated data is typically stored in the memory device 5a of the ground support device 5.
[0057] Furthermore, if you select any data points DP to be consecutive (for example, "a1, a2, a3, a4, a5, a6, a7" in Figures 4A and 4B), the horizontal axis will show "Total Electron Content (TECU)", "S4 (μSv)", and "Water Vapor Content (g / m³)" for the selected data points DP (a1, a2, a3, a4, a5, a6, a7). ３ A distribution map can be obtained with the value of "(μSv)" on the vertical axis. The ionospheric and tropospheric state measurement system 1 can, in various ways, associate "total electron content (TECU)", "S4 (μSv)", and "water vapor content (g / m³)" with measurement points (points specified by latitude and longitude) indicated by data points DP (black dots). ３ It is possible to provide the value of ) .
[0058] As described above, according to a predetermined embodiment of the present invention, two-frequency GNSS data is acquired from a moving object such as an aircraft or ship to measure the state of the ionosphere and troposphere. Since the delay and refractive index of the acquired radio waves are very small, it is necessary to accurately determine the position and speed of the object itself. For example, the position of the object can be accurately determined using the GNSS receiver and IMU originally installed on the moving object. This makes it possible to measure the state of the ionosphere and troposphere in real time, even in areas where atmospheric observation information has been unavailable, such as over the sea or in difficult-to-reach places on land.
[0059] Furthermore, by applying this invention to aircraft, the amount of water vapor at low altitudes can be determined by calculating the cumulative amount of water vapor during takeoff and landing. When the aircraft is in level flight, the amount of water vapor can be determined using the occultation method. When observing from the ground or sea, even if the total amount of water vapor in the upper atmosphere is known, it is not possible to measure which layer (altitude) has a high amount of water vapor. However, by using an aircraft, observation data can be obtained during ascent and descent, and the layer with a high amount of water vapor can be estimated. In addition, by using different methods for measuring water vapor depending on the altitude, atmospheric measurements can be effectively performed in both low-altitude and high-altitude phases.
[0060] Furthermore, applying the present invention to scheduled air travel enables constant and dense fixed-point observation of ionospheric and tropospheric states. Conventionally, observations have been made using weather balloons for weather forecasting and other purposes, but the locations and frequency of these observations are limited, resulting in limited observation data. By applying the present invention to scheduled air travel, ground support equipment can perform fixed-point observations of at least one of the ionospheric and tropospheric states based on measurement data acquired from multiple aircraft operating regularly on the same route. This makes it possible to perform fixed-point observations of GNSS data at many locations, which can be used for daily weather forecasts and is expected to improve forecast accuracy.
[0061] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented in various other forms without departing from the spirit of the invention. For this reason, the above embodiments are merely illustrative in all respects and should not be interpreted restrictively. For example, some of the above processing steps can be omitted, or the order of the processing steps can be arbitrarily changed or executed in parallel, as long as no inconsistency arises in the processing content.
[0062] In the above embodiment, the ionospheric-tropospheric measurement device 4 is described as being connected by wire or wireless to a memory device 23 storing the position data of the aircraft 2, and the ionospheric-tropospheric measurement device 4 can acquire the position data of the aircraft 2 from the memory device 23 according to the passage of time. However, the embodiments of the present invention are not limited to this. For example, the position data acquired by the GNSS receiver 21 and IMU 22 may be transmitted from the control system 2a to the ground support device 5. In this case, the GNSS data measured by the ionospheric-tropospheric measurement device 4 is transmitted from the aircraft 2 to the ground support device 5 separately from the position data. The ground support device 5 may then measure the state of the ionosphere and troposphere by associating the position data and GNSS data based on the measurement time, etc.
[0063] 1. Ionospheric and Tropospheric State Measurement System 2. Aircraft (Mobile) 2a. Piloting System 21. Inertial Navigation Unit (IMU) 22. Memory Unit 3, 31, 32, 33. Artificial Satellite (Positioning Satellite) 4. Ionospheric and Tropospheric Measurement Unit 4a. Memory Unit 5. Ground Support Equipment 5a. Memory Unit 221. First Inertial Navigation Unit (First IMU) 222. Second Inertial Navigation Unit (Second IMU)
Claims
1. A state measurement system comprising: an ionospheric-tropospheric measurement device mounted on an aircraft that receives positioning signals including radio waves in at least two frequency bands from a positioning satellite and acquires predetermined measurement data; and a ground support device that measures the state of at least one of the ionosphere and the troposphere based on the measurement data received from the ionospheric-tropospheric measurement device and the aircraft's position data received from the aircraft.
2. The status measurement system according to claim 1, wherein the position data is acquired using a GNSS receiver and IMU provided by the aircraft.
3. The state measurement system according to claim 1 or 2, wherein the aircraft is a scheduled flight, and the ground support device performs fixed-point observation of the state of at least one of the ionosphere and the troposphere based on measurement data acquired from multiple aircraft operating regularly on the same route.
4. The state measurement system according to claim 1 or 2, wherein the ionospheric and tropospheric measuring device acquires the measurement data at predetermined time intervals or at predetermined altitude changes during the takeoff and landing of the aircraft, and the ground support device measures the amount of water vapor in the atmospheric layer over a certain section.
5. An ionosphere and tropospheric state measurement system comprising: an artificial satellite capable of transmitting radio waves in at least two frequency bands and capable of positioning; an aircraft equipped with a GNSS receiver and an IMU as part of a control system, the aircraft equipped with a memory device for storing the aircraft's position data acquired by the GNSS receiver and the IMU; and an ionospheric and tropospheric measuring device mounted on the aircraft, connected to the GNSS receiver and the IMU in a communicative manner and capable of receiving the radio waves, wherein the system receives the radio waves in at least two frequency bands, the ionospheric and tropospheric measuring device acquires the aircraft's position data at the time of the reception of the radio waves from the aircraft's memory device, the ionospheric and tropospheric measuring device associates the radio wave signals with the position of the measurement point and stores the association in the memory device of the ionospheric and tropospheric state measurement system.
6. An ionospheric and tropospheric state measurement system according to claim 5, wherein the ionospheric and tropospheric state measurement system further comprises a ground support device that is communicably connected to the ionospheric and tropospheric measurement device, the ionospheric and tropospheric measurement device calculates propagation delay amounts of two frequencies from the radio wave signal, calculates at least one of "total electron count," "S4," and "water vapor amount" in the ionosphere from the propagation delay amounts of the two frequencies, associates it with the position of the measurement point, and transmits it to the ground support device, or the ionospheric and tropospheric measurement device transmits the radio wave signal to the ground support device, the ground support device calculates propagation delay amounts of two frequencies from the radio wave signal, calculates at least one of "total electron count," "S4," and "water vapor amount" in the ionosphere from the propagation delay amounts of the two frequencies, and associates it with the position of the measurement point.
7. An ionospheric and tropospheric state measurement system according to claim 5 or 6, wherein, in the association between the radio wave signal and the position of the measurement point, the measurement point is defined as a point between the artificial satellite and the aircraft.
8. An ionospheric and tropospheric state measurement system according to claim 5, wherein the ionospheric and tropospheric state measurement system further comprises a ground support device that is communicably connected to the ionospheric and tropospheric measurement device, the ionospheric and tropospheric measurement device calculates an arrival delay amount from the signal of the radio waves, calculates an accumulated amount of water vapor from the arrival delay amount, associates it with the position of the measurement point, and transmits it to the ground support device, or the ionospheric and tropospheric measurement device transmits the signal of the radio waves to the ground support device, the ground support device calculates the arrival delay amount from the signal of the radio waves, calculates an accumulated amount of water vapor from the arrival delay amount, and associates it with the position of the measurement point.
9. An ionospheric and tropospheric state measurement system according to claim 8, wherein the system receives radio waves at predetermined intervals before and after the aircraft's takeoff, calculates a propagation delay from the signal of the radio waves received before the aircraft's takeoff, calculates an integrated water vapor amount from the propagation delay and defines it as a tropospheric state measurement reference quantity, calculates a propagation delay from the signal of each of the radio waves received at predetermined intervals after the aircraft's takeoff, calculates an integrated water vapor amount from each propagation delay, subtracts the integrated water vapor amount from the tropospheric state measurement reference quantity, and defines the difference as the amount of water vapor in the atmospheric layer over a certain section.
10. A measurement method for measuring the state of the ionosphere and troposphere using an ionosphere and tropospheric state measurement system comprising: an artificial satellite capable of transmitting radio waves in at least two frequency bands and capable of positioning; an aircraft equipped with a GNSS receiver and an IMU as part of a control system, the aircraft equipped with a memory device for storing position data of the aircraft acquired by the GNSS receiver and the IMU; and an ionosphere-tropospheric measuring device mounted on the aircraft, connected to communicate with the GNSS receiver and the IMU and capable of receiving the radio waves, the measurement method comprising: receiving the radio waves in at least two frequency bands with the ionosphere-tropospheric measuring device, and acquiring the position data of the aircraft at the time the ionosphere-tropospheric measuring device received the radio waves from the aircraft's memory device; and associating the radio wave signals with the position of the measurement point and storing it in the memory device of the ionosphere-tropospheric measuring device.
11. A method for measuring the ionosphere and troposphere state according to claim 10, wherein the ionosphere and troposphere state measurement system further comprises a ground support device that is communicably connected to the ionosphere and troposphere measurement device, the ionosphere and troposphere measurement device calculates propagation delay amounts of two frequencies from the signal of the radio waves, calculates at least one of "total electron count," "S4," and "water vapor amount" in the ionosphere from the propagation delay amounts of the two frequencies, associates it with the position of the measurement point, and transmits it to the ground support device, or the ionosphere and troposphere measurement device transmits the signal of the radio waves to the ground support device, the ground support device calculates propagation delay amounts of two frequencies from the signal of the radio waves, calculates at least one of "total electron count," "S4," and "water vapor amount" in the ionosphere from the propagation delay amounts of the two frequencies, and associates it with the position of the measurement point.
12. An ionospheric and tropospheric state measurement method according to claim 10 or 11, wherein, in relating the signal of the radio waves to the position of the measurement point, the measurement point is defined as a point between the artificial satellite and the aircraft.
13. A method for measuring the ionosphere and troposphere state according to claim 10, wherein the ionosphere and troposphere state measurement system further comprises a ground support device that is communicably connected to the ionosphere and troposphere measuring device, the ionosphere and troposphere measuring device calculates a propagation delay amount from the signal of the radio waves, calculates an accumulated amount of water vapor from the propagation delay amount, associates it with the position of the measurement point, and transmits it to the ground support device, or the ionosphere and troposphere measuring device transmits the signal of the radio waves to the ground support device, the ground support device calculates the propagation delay amount from the signal of the radio waves, calculates an accumulated amount of water vapor from the propagation delay amount, and associates it with the position of the measurement point.
14. A method for measuring the ionosphere and tropospheric state according to claim 13, comprising the steps of: receiving radio waves at predetermined time intervals before and after the aircraft takeoff; calculating a propagation delay amount from the signal of the radio waves received before the aircraft takeoff; calculating the cumulative water vapor amount from the propagation delay amount and defining it as a tropospheric state measurement reference amount; and calculating a propagation delay amount from the signal of each of the radio waves received at predetermined time intervals after the aircraft takeoff; calculating the cumulative water vapor amount from each propagation delay amount; subtracting the cumulative water vapor amount from the tropospheric state measurement reference amount; and defining the difference as the amount of water vapor in the atmospheric layer over a certain section.