Patent Description:
Wind power is an important part of the future <NUM>% renewable energy mix. In <NUM>, the global wind power installed capacity was <NUM> GW (<NUM> GW onshore wind and <NUM> GW offshore wind). It is foreseen that by <NUM>, this number will grow by <NUM>% to <NUM> GW (<NUM> GW onshore wind and <NUM> GW offshore wind), enough to cover <NUM>% of the global electricity generation mix. By <NUM>, the accelerated deployment of wind power can contribute to avoided emissions of up to <NUM> gigaton CO<NUM> per year, according to "Future of wind, Deployment, investment, technology, grid integration and socio-economic aspects", International Renewable Energy Agency, October <NUM>. As described, wind power is an integral part of today's and the future's global sustainable electricity supply and economy.

In order to construct new wind farms, prospective wind farm sites are chosen. To evaluate the wind energy potential of a prospective wind farm sufficiently, on-site weather monitoring equipment, especially wind property monitoring equipment must be used for at least one year.

Currently, meteorological masts, met masts for short, are used for on-site weather monitoring at prospective wind farm sites. Met masts are the current industry standard. Referring to <FIG>, a met mast <NUM> comprises of several sensors and anemometers <NUM> located in different heights on a self-supporting or guyed steel lattice tower. The met mast <NUM> is onshore in <FIG>, that is on the ground <NUM>. The met mast <NUM> can also be located/installed offshore, that is in the water <NUM>. The met mast <NUM> structure is typically between <NUM> to <NUM> meters in height and is built and transported in several sections. The weight of the whole structure can be up to <NUM> metric tons, while in an offshore setting it can typically reach to more than <NUM> tons of steel. The offshore met mast is usually supported by a concrete foundation can weight as much as <NUM> tons depending on the water depth. The huge weight of a met mast makes it difficult to transport and install.

Besides the enormous weight, the met mast is quite expensive. Met masts are typically installed with several kilometers distance from each other. A <NUM>-meter onshore met mast costs approximately € <NUM>,<NUM> to € <NUM>,<NUM> to buy and install, and an extra permit fee is also needed. An offshore met mast costs on average around € <NUM>-<NUM> million to procure and install. The maintenance of a met mast is also expensive.

Besides the met mast, remote sensing (RS) devices can also be used on a prospective wind farm. Referring to <FIG>, RS devices collect/record wind characteristics in a large area by means of either light detection and ranging (LiDAR) <NUM> or sound/sonic detection and ranging (SoDAR) <NUM>. The LiDAR <NUM> is a device that works based on laser technology, and measures the backscattered light from the atmosphere to determine atmospheric conditions. The SoDAR <NUM> is a wind profiling technology which works by measuring the scattering of sound waves or acoustic signals by atmospheric turbulence. The RS devices can be installed both onshore and offshore.

Even though RS devices are significantly cheaper than installing and maintaining a met mast, they cannot be used to measure some of the critical parameters of the wind such as humidity, pressure, and temperature. Moreover, the measurement uncertainty of RS devices is usually considered to be lower than met masts. Therefore, RS devices are rarely used as standalone wind measurement solutions. In other words, using only RS devices can not necessarily ensure a bankable dataset for prospective wind farms. As the result, RS devices are most often used in combination with met masts for reducing data uncertainty.

The use of RS devices in combination with met masts can lower the costs of the whole wind/weather monitoring system to some degree since the developers could install fewer met masts at the prospective project site.

In addition, due to met masts being massive and bulky structures, special equipment and considerable manpower is needed to install, maintain, and finally dismantle them. In an offshore environment, this will be a much bigger issue since large vessels and cranes are needed to install/dismantle each met mast. Offshore met masts need heavy support structures, while onshore met masts need foundations and land preparation. Moreover, each mast needs to be designed and manufactured according to the environmental restrictions prior to installation, which makes the whole process more complex, expensive, and time consuming.

Since there will be only a few met masts for each prospective wind farm, certain intermediate wind characteristics are estimated by using mathematical models and extrapolation, which increases the uncertainty of the recorded dataset. The complementary usage of RS devices can partly reduce this issue. However, these devices can only partly help since they are not able to record some parameters such as temperature, atmospheric pressure, and humidity.

Moreover, anemometers used in met masts are subject to occasional over-speeding and freezing which will lower the accuracy and reliability of data collection. RS devices are also subject to being buried in snow and data inaccuracies during rain and fog which further hampers their ability to gather reliable data.

Furthermore, met masts are required to be installed on a foundation in general. Concrete, hammered monopile, or even jacket structures of the foundation all have considerable environmental impacts for offshore locations. Aside from the lifecycle carbon footprint of using large amounts of steel and concrete in such foundations and the met mast structure itself, the installation poses damage to the environment. Beside the met mast and the remote sensing devices, drones can be used to pass weather reports. An example can be found in <CIT>.

Therefore, there is a need for an autonomous, economical, flexible, and accurate meteorological data obtaining system, which is easy to install and maintain, and has less negative impact on the environment. Such meteorological data comprises wind property data and other weather-related data.

Besides prospective wind farms, there are other sites or occasions which also need such autonomous meteorological data obtaining system, e.g., real-time monitoring of aeroallergens or other atmospheric aerosols/particulates, measurements of pollution and greenhouse gas concentration, monitoring of ocean, seas and coastal waters, biodiversity and bio-based economy observations, etc..

It is an object of the invention to address at least some of the problems and issues outlined above. It is an object of embodiments of the invention to provide an economical, flexible, accurate and environmentally friendly meteorological data obtaining method and system. It is an object of embodiments of the invention to obtain accurate and complete meteorological data. It is possible to achieve these objects and others by using methods and system as defined in the attached independent claims.

According to one aspect, a method is provided for obtaining meteorological data by an unmanned aerial system, UAS, according to claim <NUM>.

According to another aspect, an unmanned aerial system, UAS, for obtaining meteorological data, according to claim <NUM>.

Further possible features and benefits of this solution will become apparent from the detailed description below.

An unmanned aerial vehicle (UAV) is an aircraft without a human pilot, crew, or passengers on board. UAVs are also more commonly known as drones. UAVs are usually a component of an unmanned aerial system (UAS). The UAS can be an autonomous system which also includes a ground-based controller and a communication system communicating with the UAV. Since the UAV is flexible, environmentally friendly, cheap, easily deployable and accurate, the UAV and UAS are suitable for obtaining meteorological data in an onshore or offshore prospective wind farm, or other sites which need meteorological data acquisition.

<FIG>, in conjunction of <FIG>, shows a method performed by an unmanned aerial system, UAS, according to an exemplary embodiment. The method is used for obtaining meteorological data by an unmanned aerial system, UAS <NUM>, <NUM>, the UAS <NUM>, <NUM> comprises at least one unmanned aerial vehicle, UAV <NUM>, <NUM>, a control center <NUM>, <NUM> and a wireless communication interface <NUM>, <NUM>. The at least one UAV <NUM>, <NUM> is equipped with a meteorological data sensor <NUM> and a flight controller <NUM>, FC and the at least one UAV <NUM>, <NUM> is configured for wireless communication with the control center <NUM>, <NUM> via the wireless communication interface <NUM>, <NUM> during flight. The method comprises sending <NUM> flight instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to perform flight. The method further comprises performing <NUM> flight, by the at least one UAV <NUM>, <NUM>, according to the flight instruction data and collecting <NUM> raw meteorological data and flight data, by the at least one UAV <NUM>, <NUM> during the flight, wherein the raw meteorological data is collected by the meteorological data sensor <NUM> and the flight data is collected by the FC <NUM>, wherein the flight data being collected by any one of a position sensor, a motion sensor, an environment sensor and/or a combination thereof included in the FC <NUM>. The method further comprises transmitting <NUM>, in real time, the collected <NUM> raw meteorological data and the flight data, from the at least one UAV <NUM>, <NUM> to the control center <NUM>, <NUM>, during the flight, via the wireless communication interface <NUM>, <NUM> of the UAS <NUM>, <NUM> and calculating <NUM> meteorological data, in the control center <NUM>, <NUM>, based on the received raw meteorological data and the flight data in the transmitting <NUM> step. The method further comprises sending <NUM> return instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to return to the UAS <NUM>, <NUM> and returning <NUM> the at least one UAV <NUM>, <NUM> to the UAS <NUM>, <NUM>, according to the return instruction data.

The at least one UAV <NUM>, <NUM> can be any kind of UAV which is suitable for flying in a windy environment, e.g., fixed-wing UAV, fixed-wing vertical take-off and landing (VTOL) UAV. The structure of the UAV will be discussed later in this disclosure.

In the step <NUM>, the UAV <NUM>, <NUM> is instructed by the control center <NUM>, <NUM> to perform flight on the prospective wind farm or other sites which need to obtain meteorological data. The flight instruction data can comprise the flight schedule, flight direction, flight path, destination information, etc. The UAV <NUM>, <NUM> performs flight accordingly in step <NUM>.

In the step <NUM>, during the flight, the UAV <NUM>, <NUM> collects raw meteorological data with the meteorological data sensor <NUM> installed thereon. The collected raw meteorological data can include e.g., wind speed, wind direction, wind frequency, turbulence intensity, humidity, temperature, atmospheric pressure, aeroallergen concentration, atmospheric aerosols/particulates, pollution, greenhouse gas concentration, which are examples of possible types of meteorological data which are related to wind property and other environmental properties. The meteorological data sensor <NUM> can be a pitot tube, a hot wire sensor, a laser doppler sensor, an ultrasonic/acoustic sensor, a humidity sensor, a temperature sensor, a gas concentration sensor, an aerosol sensor, etc. and/or combination of any of these sensors. A pitot tube is a flow measurement device used to measure air flow velocity and pressure. For example, the wind speed can be measured and collected by the pitot tube. A hot wire sensor is also called a hot wire mass airflow sensor. For example, the wind speed, wind direction and/or turbulence intensity can be detected by the hot wire sensor. Laser doppler sensors and acoustic sensors use light and sound wave propagation/reflection respectively to measure the changes in the air. Other kinds of sensors and equipment can also be equipped, e.g., a camera, a collision avoidance sensor, an infrared (IR) sensor, etc. The camera can be used to take photos or record videos of the site. A collision avoidance sensor can also be equipped to the UAV <NUM>, <NUM> so as to avoid any collision with stationary and flying objects, such as birds or other UAV. The collision avoidance sensor can be based on GPS technology and/or Radar, Lidar and/or Sonar principles. An infrared sensor can be used to detect heat signatures and temperature fluctuations. Other types of data can be collected depending on the type of sites and according to different scenarios/applications.

Also in the step <NUM>, during the flight, the UAV <NUM>, <NUM> collects or measures flight data with the FC <NUM> provided thereon. The flight data can be real time flight related data of the UAV <NUM>, <NUM>,e.g., the flying speed of the UAV <NUM>, <NUM>, the flying direction, the acceleration, the azimuth and elevation, the height, the position, the GPS data, the magnetic field strength of the environment in which the flight being performed, and other flight related data in three dimensional space. The FC <NUM> can be equipped with different types of sensors, e.g., position sensors, motion sensors and/or environment sensors, etc. The different sensors can be e.g., a gyroscope, an accelerometer, an inertial measurement unit (IMU), a barometer, a magnetometer, GPS and/or a combination of any of these devices. The position sensors, motion sensors and/or environment sensors equipped on the FC <NUM> are used to collect real time flight data of the UAV <NUM>, <NUM>.

In the step <NUM>, the collected raw meteorological data and the flight data is transmitted from the UAV <NUM>, <NUM> to the control center <NUM>, <NUM> of the UAS <NUM>, <NUM>, in real time. The transmission is performed via the wireless communication interface <NUM>, <NUM> of the UAS <NUM>, <NUM>. The wireless communication between the UAV <NUM>, <NUM> and the wireless communication interface <NUM>, <NUM> can use any suitable radio telecommunication protocol, e.g., <NUM>, LTE, <NUM>, UranusLink, Uncomplicated Application-level Vehicular Computing and Networking (UAVCAN), Micro Air Vehicle Link (MAVLink), Ad hoc.

In the step <NUM>, the control center <NUM>, <NUM> calculates meteorological data based on the received raw meteorological data and the flight data in step <NUM>. The received raw meteorological data and flight data is real time data which represents the current meteorological and flight situation. Since both meteorological data and the flight data are considered, the calculation of the meteorological data is accurate. The calculated meteorological data includes wind property data and other environmental data, e.g., accurate wind speed, wind direction, turbulence intensity, humidity, temperature, pressure, etc. For example, the accurate wind speed is calculated based on the wind speed measured/collected by the meteorological data sensor <NUM>, and the flying speed of the UAV <NUM>, <NUM> measured/collected by sensors equipped on the FC <NUM>. Since the measured wind speed is actually a relative wind speed in relation to the UAV <NUM>, <NUM>, when considering the speed of the UAV <NUM>, <NUM>, a more accurate wind speed is calculated by the control center <NUM>, <NUM>. Similarly, a more accurate wind direction is calculated when considering the azimuth, inclination, and elevation of the UAV <NUM>, <NUM>. To be specific, the UAV <NUM>, <NUM> may perform flight in an angle or in a direction which is not parallel to the horizontal surface. This real-time flying direction/angle is measured/collected by the FC <NUM>. When measuring the wind direction/angle with the meteorological data sensor <NUM>, the measured wind direction/angle is actually the relative direction/angle to the UAV <NUM>, <NUM>. Thus, the measured wind direction/angle is not the "real" or accurate wind direction/angle relative to the horizontal surface. In this situation, when a "real" or accurate wind direction/angle is calculated, both the measured wind direction/angle and the UAV <NUM>, <NUM> flying direction/angle should be considered in calculation. Therefore, the meteorological data is calculated based on both raw meteorological data and collected flight data. As for the calculation of turbulence intensity, turbulence intensity is the ratio of standard deviation of wind speed to the mean wind speed. On one hand, when the meteorological sensor <NUM> measures/collects wind speed at a high frequency, more raw wind speed data points are recorded. On the other hand, when the UAV <NUM>, <NUM> is flying, a changing wind speed can affect the UAV flying status by exerting a varying force to the UAV body. The accelerometer(s) equipped on the FC <NUM> can measure these small changes. By combining the raw wind speed data points measured by the meteorological <NUM> and the acceleration data measured/collected by the accelerometer(s) equipped on the FC <NUM>, the calculation of the turbulence intensity becomes more accurate. Additionally, machine learning tools/methods can be used in and enhance such calculation. Therefore, an accurate turbulence intensity can be calculated using a high frequency of recordings from the meteorological sensor <NUM> and from the FC <NUM>. The calculation <NUM> is performed by a preinstalled software or predefined algorithm in the control center <NUM>, <NUM>.

In the steps <NUM> and <NUM>, the UAV <NUM>, <NUM> returns to the stationary part of the UAS <NUM>, <NUM> in response to a return instruction data from the control center <NUM>, <NUM>. Thus, the mission of the UAV <NUM>, <NUM> is accomplished.

Comparing with met masts and RS devices in prior art, the measurement of the meteorological data is done at the precisely intended measurement locations, whereas met masts and RS devices widely use mathematical extrapolation or approximation for wind characterization. Therefore, the disclosed embodiment can greatly reduce the measurement uncertainty for meteorological data. Furthermore, the real time flight data of the at least one UAV <NUM>, <NUM> is taken into account when calculating the meteorological data. Thus, by such a method, the calculated meteorological data is much more accurate.

According to an embodiment, the step of calculating <NUM> meteorological data comprises calculating wind speed and the method further comprises sending return instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to return to the UAS <NUM>, <NUM> when the calculated <NUM> wind speed exceeds a wind speed threshold.

Considering the prospective wind farm scenario, modern wind turbines shut down at a wind speed of <NUM>/s due to safety reasons. Meanwhile, the UAV <NUM>, <NUM> may withstand winds of up to <NUM>/s based on its size, weight and design. A higher wind speed may damage the UAV <NUM>, <NUM>. Thus, the threshold can be <NUM>/s - <NUM>/s in the wind farm scenario. The speed threshold can be other numbers in other scenarios, for example, the speed threshold can be lower when the wind is not so strong on-site. When the windstorm has passed, the UAV <NUM>, <NUM> can perform flight again in response to the flight instruction data.

According to an embodiment, the flight instruction data sent <NUM> to the at least one UAV <NUM>, <NUM> comprises flight path for each of the at least one UAV <NUM>, <NUM>, wherein the method further comprises transmitting, in real time an energy status of each of the at least one UAV <NUM>, <NUM>, from the at least one UAV <NUM>, <NUM> to the control center <NUM>, <NUM>, during the flight, via the wireless communication interface <NUM>, <NUM> of the UAS <NUM>, <NUM>. The method further comprises calculating, in the control center <NUM>, <NUM>, an updated flight path for each of the at least one UAV <NUM>, <NUM> based on the collected raw meteorological data, the flight data and the energy status of the at least one UAV <NUM>, <NUM> and sending, updated flight instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM> in flight, updating the flight path of the at least one UAV <NUM>, <NUM>.

The UAV <NUM>, <NUM> can be powered by batteries. When the UAV <NUM>, <NUM> is stored in the UAS <NUM>, <NUM>, it will be charged by the charging station in the UAS <NUM>, <NUM>. The UAV <NUM>, <NUM> can also be equipped with a portable fuel tank for emergency situations during flight. For example, if one of the UAV motors can be run on both electricity from the batteries and fuel from the fuel tank, in case the UAV <NUM>, <NUM> is caught in very strong winds or the battery electricity is not sufficient to return the UAV <NUM>, <NUM> back to the UAS <NUM>, <NUM>, the motor can use the fuel from the fuel tank for a short period until the UAV <NUM>, <NUM> is returned safely. Furthermore, the UAV <NUM>, <NUM> can also be retrofitted with light-weighted solar panels on wings to directly charge the onboard batteries during flight to extend the flight time.

The UAV <NUM>, <NUM> performs flight according to the flight path contained in the received flight instruction data. The UAV <NUM>, <NUM> can monitor its own energy status and send the energy status to the control center <NUM>, <NUM> in real time wirelessly. The control center <NUM>, <NUM> monitors the status of the flying UAV <NUM>, <NUM> by checking the meteorological data, the flight data, the energy status, and any other necessary environmental data required with respect to measurement's main purpose. An updated flight path for the UAV <NUM>, <NUM> is calculated based on the meteorological data, the flight data and the energy status. For example, according to updated flight path, the UAV <NUM>, <NUM> is required to perform an altitude change, destination change, or is required to maintain its position in the air or is required to circulate a certain spot for a period or is required to perform any other specific maneuver for the purpose of data surveying, environmental, or safety reasons. The updated flight path is sent to the UAV <NUM>, <NUM> during the flight and the UAV <NUM>, <NUM> will perform its flight according to the updated flight path in real time. The calculation of the flight path is performed in the control center <NUM>, <NUM>. In one embodiment, the control center <NUM>, <NUM> will calculate the prominent wind speed and wind direction based on the received sensor measurements and UAV <NUM>, <NUM> flight data. The control center <NUM>, <NUM> will then decide on the outermost distance that the UAV <NUM>, <NUM> can have from the UAS <NUM>, <NUM> in order to stay above a minimum required energy status until the UAV <NUM>, <NUM> can safely return to the UAS <NUM>, <NUM>. This is because flying against the wind will faster drain energy from the UAV <NUM>, <NUM>. If the return path of the UAV <NUM>, <NUM> to the UAS <NUM>, <NUM> has the same general direction as to the prominent wind, this distance will be longer, whereas if the return path is the opposite of the prominent wind, this distance will be shorter. The control center <NUM>, <NUM> will then send corrective updates to the flight path, instructing the UAV <NUM>, <NUM> to always stay within this allowed distance. In another embodiment, the meteorological sensor shows a freezing temperature at the UAV <NUM>, <NUM>. In the control center <NUM>, <NUM>, according to measured wind speed, temperature and humidity, a calculation will be made that predicts how long time it will take for the UAV <NUM>, <NUM> propellers and/or wings to experience what is referred to as icing. Icing is the formation of ice particles on an aerofoil, such as wings and rotating blades. Icing reduces flight effectiveness. The control center <NUM>, <NUM>, thereafter, will send updated flight instructions to the UAV <NUM>, <NUM> in order to prevent icing. These updated instructions can either be decreasing the flight speed, changing the flight direction, turning on the onboard blade heaters, returning to the UAS <NUM>, <NUM>, etc. or any other combination of these. In another embodiment, the control center <NUM>, <NUM>, at predefined intervals, will send updated coordinates and flight height for the return path to the UAS <NUM>, <NUM> in case the data transmission signal is temporarily lost. In another embodiment, the control center <NUM>, <NUM> will send updated flight path to the UAV in case a flock of birds is passing nearby, so that the UAV <NUM>, <NUM> can maintain a safe distance from the animals without disrupting their movement or scaring them. In another embodiment, the allowed flight ceiling and allowed flight area is communicated to the UAV <NUM>, <NUM> based on the most recent local flight restrictions. In another embodiment, when the wind speed is lower than a certain threshold, and the energy status of the UAV <NUM>, <NUM> is higher than a certain threshold, an updated instruction to prolong the flight path may be initiated and sent to the UAV <NUM>, <NUM>.

By this method, a real time updating of the UAV <NUM>, <NUM> flight path is achieved. The real time updating of the flight path takes many factors into account, and an optimal flight path can be calculated in real time. The optimal flight path can maintain the most effective coverage of the surveyed area. The calculation is performed by the control center <NUM>, <NUM>, and different machine learning methods can be used to perform/enhance the calculation.

According to another embodiment, more than one UAV <NUM>, <NUM> are used, so that these UAVs <NUM> can take turns to perform flight and measurements to guarantee continuous working of the UAS <NUM>, <NUM> so that the UAS <NUM>, <NUM> is always under operation. The working schedule of all the UAVs <NUM>, <NUM> are controlled by the control center <NUM>, <NUM>, so that all the UAVs <NUM>, <NUM> are properly working, and effectively alternating between stand-by mode, charging mode, and flight mode. In case of malfunction or any unexpected interruptions to one of the UAVs <NUM>, <NUM>, the control center <NUM>, <NUM> will give instructions to stand-by UAVs to perform flight and measurements. The collected meteorological data, the flight data, the energy status of UAVs <NUM>, <NUM>, e.g., positions of all the UAVs <NUM>, <NUM>, heights, flight speeds, flight direction, wind speed, wind direction, battery level, etc. are used by the control center <NUM>, <NUM> to schedule the whole UAS <NUM>, <NUM>, so that there is always at least one UAV <NUM>, <NUM> which performs flight and measurement.

According to an embodiment, the UAS <NUM>, <NUM> further comprises a tethered meteorological data sensor <NUM>, <NUM>, which is arranged to collect raw meteorological data at different heights, and wherein the method further comprises transmitting the raw meteorological data collected by the tethered meteorological data sensor <NUM>, <NUM> to the control center <NUM>, <NUM>.

The tethered meteorological data sensor <NUM>, <NUM> can be located on a tethered balloon, a tethered blimp or a tethered UAV which is either fixed winged, multi-rotor, or any hybrid combination of the previously mentioned. The tethered meteorological data sensor <NUM>, <NUM> can also be other forms which are tethered to the UAS <NUM>, <NUM> on one end with a winch or other connecting apparatus. The tethered meteorological data sensor <NUM>, <NUM> is similar to the meteorological data sensor <NUM>, which is equipped on the UAV <NUM>, <NUM> and can collect possible types of meteorological and environmental data, e.g., wind speed, wind direction, wind frequency, turbulence intensity, humidity, temperature, atmospheric pressure, aeroallergen concentration, atmospheric aerosols/particulates, pollution, greenhouse gas concentration, etc. Since the length of the tether is adjustable, the tethered meteorological data senser <NUM>, <NUM> can collect meteorological data at different heights in long term or short term. The meteorological data collected by the tethered meteorological data sensor <NUM>, <NUM> is transmitted to the control center <NUM>, <NUM> and the control center <NUM>, <NUM> calculates meteorological data also based on the raw meteorological data collected by the tethered meteorological data sensor <NUM>, <NUM>.

According to an embodiment, the UAS <NUM>, <NUM> further comprises a fixed meteorological data sensor <NUM>, <NUM>, which is arranged to collect raw meteorological data at the UAS <NUM>, <NUM>, and wherein the method further comprises transmitting the raw meteorological data collected by the fixed meteorological data sensor <NUM>, <NUM> to the control center <NUM>, <NUM>.

The fixed meteorological data sensor <NUM>, <NUM> has similar functions as the meteorological data sensor <NUM>, which is equipped on the UAV <NUM>, <NUM> and can collect possible types of meteorological data, e.g., wind speed, wind direction, wind frequency, turbulence intensity, humidity, temperature, atmospheric pressure, aeroallergen concentration, atmospheric aerosols/particulates, pollution, greenhouse gas concentration, etc. The meteorological data collected by the fixed meteorological data sensor <NUM>, <NUM> is transmitted to the control center <NUM>, <NUM> and the control center <NUM>, <NUM> calculates meteorological data also based on the raw meteorological data collected by the fixed meteorological data sensor <NUM>, <NUM>. One advantage of the fixed meteorological data sensor <NUM>, <NUM> is that the fixed meteorological data sensor <NUM>, <NUM> keeps on working even in an extreme environment. For example, during a windstorm or a thunderstorm, the UAV <NUM>, <NUM> is instructed to return to the UAS <NUM>, <NUM> and cannot continue performing the measurement, but the fixed meteorological data sensor <NUM>, <NUM> can still measure and transmit meteorological data to the control center <NUM>, <NUM>.

<FIG>, in conjunction with <FIG>, <FIG>, discloses a UAS <NUM>, <NUM>, for obtaining meteorological data. The UAS <NUM>, <NUM> comprises at least one unmanned aerial vehicle, UAV <NUM>, <NUM>, a control center <NUM>, <NUM> and a wireless communication interface <NUM>, <NUM>. The at least one UAV <NUM>, <NUM> is equipped with at least one meteorological data sensor <NUM> and a flight controller, FC <NUM>. The at least one UAV <NUM>, <NUM> is arranged for wireless communication with the control center <NUM>, <NUM> via the wireless communication interface <NUM>, <NUM> during flight. The control center <NUM>, <NUM> and the FC <NUM> of the at least one UAV <NUM>, <NUM> comprise instructions which when executed cause the system to send flight instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to perform flight. The system is further caused to perform flight, by the at least one UAV <NUM>, <NUM>, according to the flight instruction data and collect meteorological data and flight data, by the at least one UAV <NUM>, <NUM> during the flight, wherein the raw meteorological data is collected by the meteorological data sensor <NUM>, and the flight data is collected by the FC <NUM>, wherein the flight data being collected by any one of a position sensor, a motion sensor, an environment sensor and/or a combination thereof included in the FC <NUM>. The system is further caused to transmit, in real time, the collected raw meteorological data and the flight data, from the at least one UAV <NUM>, <NUM> to the control center <NUM>, <NUM>, during the flight, via the wireless communication interface <NUM>, <NUM> of the UAS <NUM>, <NUM> and calculate meteorological data, in the control center <NUM>, <NUM>, based on the received raw meteorological data and the flight data. The system is further caused to send return instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to return to the UAS <NUM>, <NUM> and return the at least one UAV <NUM>, <NUM> to the UAS <NUM>, <NUM>, according to the return instruction data.

According to an embodiment, the calculating of meteorological data comprises calculating wind speed and the control center <NUM>, <NUM> is further caused to send return instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM>, instructing the at least one UAV <NUM>, <NUM> to return to the UAS <NUM>, <NUM>, when the calculated wind speed exceeds a wind speed threshold.

According to another embodiment, the flight instruction data sent to the at least one UAV <NUM>, <NUM> comprises flight path for each of the at least one UAV <NUM>, <NUM>, the at least one UAV <NUM>, <NUM> is further caused to transmit, in real time, an energy status of each of the at least one UAV <NUM>, <NUM>, from the at least one UAV <NUM>, <NUM> to the control center <NUM>, <NUM>, during the flight, via the wireless communication interface <NUM>, <NUM> of the UAS <NUM>, <NUM>. The control center <NUM>, <NUM> is further caused to calculate an updated flight path for each of the at least one UAV <NUM>, <NUM> based on the collected raw meteorological data, the flight data and the energy status of the at least one UAV <NUM>, <NUM> and to send updated flight instruction data, from the control center <NUM>, <NUM> to the at least one UAV <NUM>, <NUM> in flight, updating the flight path of the at least one UAV <NUM>, <NUM>.

According to another embodiment, the UAS <NUM>, <NUM> further comprises a tethered meteorological data sensor <NUM>, <NUM>, which is arranged to collect raw meteorological data at different heights, and the tethered meteorological data sensor <NUM>, <NUM> is caused to transmit raw meteorological data collected by the tethered meteorological data sensor <NUM>, <NUM> to the control center <NUM>, <NUM>.

According to another embodiment, the UAS <NUM>, <NUM> further comprises a fixed meteorological data sensor <NUM>, <NUM>, which is arranged to collect raw meteorological data at the UAS <NUM>, <NUM>, and the fixed metrological data sensor <NUM>, <NUM> is caused to transmit the raw meteorological data obtained by the fixed meteorological data sensor <NUM>, <NUM> to the control center <NUM>, <NUM>.

According to another embodiment, the at least one UAV <NUM>, <NUM> is a fixed-wing UAV, preferably a fixed-wing vertical take-off and landing UAV.

The UAV <NUM>, <NUM> used for collecting meteorological data should be suitable for the environment, for example, windy, humid, unstable. The suitable type for UAV <NUM>, <NUM> is fixed-wing UAV, preferably fixed-wing VTOL UAV. A typical fixed-wing UAV resembles an airplane and has no vertical axis motors. A fixed-wing VTOL UAV is a hybrid of ordinary fixed-wing UAV and multi-rotors. The multi-rotors resemble helicopters, so that the fixed-wing VTOL UAV resembles a combination of airplane and helicopter. A typical fixed-wing VTOL UAV can have four vertical axis motors, which gives it the ability to take off, hover, and land vertically. They also help to maintain the position of the fixed-wing VTOL UAV in the air, that is keeping hovering without moving. Since the UAV is working in a windy environment, such function is beneficial. The number of vertical axis motors can be more than four, e.g., six or eight.

Furthermore, the UAV <NUM>, <NUM> may also comprise one or more horizontal axis motors. A horizontal axis motor helps the UAV <NUM>, <NUM> to move forward. There are different arrangements for horizontal and vertical axis motors for the UAV <NUM>, <NUM>. For example, one horizontal axis motor is used either in the back or front of the UAV <NUM>, <NUM>; two horizontal axis motors are used, one for each wing; three horizontal axis motors are used, one in back or front, two on wings; no horizontal axis motor is used, only vertical axis motors. Other ways of combining horizontal axis motor and vertical axis motor can also be applied.

For the fixed-wing VTOL UAV, it can have at least two flight modes. The first flight mode is to fly like an airplane and the second flight mode is to fly like a helicopter. A mixed flight mode where the UAV is using all its motors can also be possible. By using the vertical axis motors, the UAV can take off and land vertically, or hover while maintaining position, like a helicopter. This flight mode is also useful when the UAV is needed to stay in a position and maintain stationary measurements. By using the horizontal axis motors, the UAV can cruise at high speeds like an airplane. Most measurements can be taken in this mode. The UAV can simultaneously record measurements while flying at high speeds in a large area.

Since a prospective wind farm and other sites which need meteorological data measurements are usually prone to strong winds, there is a need for the working UAV to fly effectively with lower power for an extended duration. Since a fixed-wing structure provides long flight duration up to several hours and the VTOL structure provides maneuverability and vertical take-off/land/hover function, the fixed-wing VTOL UAV alternative provides long flight time, good maneuverability, as well as easy take-off and landing. Meanwhile, by maintaining a suitable size to weight ratio and strong UAV frame and stronger motors, the fixed-wing VTOL UAV can withstand harsher wind conditions and can be a good option to UAV <NUM>, <NUM>. Other kinds of UAV are also applicable.

According to another embodiment, the UAS <NUM>, <NUM> is retractably contained in a container <NUM>, <NUM>.

Since the UAS <NUM>, <NUM> can be utilized on different sites, it needs to be easily transportable. A container <NUM>, <NUM> is provided for an easy transportation. The container <NUM>, <NUM> can be a shipping container or any other frame structure to contain the whole UAS <NUM>, <NUM> retractably. When the UAS <NUM>, <NUM> is not working, the UAS <NUM>, <NUM> can be packed into the container <NUM>, <NUM> and being placed on land or transported by a truck or a boat.

<FIG>, <FIG> and <FIG> are schematic block diagrams for the UAS <NUM>. The UAS comprises at least one UAV <NUM>, a control center <NUM>, a wireless communication interface <NUM>. In <FIG>, three UAVs <NUM> are shown, and they are staying in the UAS <NUM>. In <FIG> and <FIG>, one UAV is performing flight and the other UAVs are staying in the UAS <NUM>. The control center <NUM> can be a computer, or any device which has sufficient calculation capacity. The wireless communication interface <NUM> is installed outside so that the UAVs can easily communicate wirelessly. A data connection is provided between the wireless communication interface <NUM> and the control center <NUM> so that the data received by the wireless communication interface <NUM> can be sent to the control center <NUM> for calculation.

Besides, according to another embodiment, the at least one UAV <NUM>, the control center <NUM>, the wireless communication interface <NUM>, the UAS <NUM> further comprises UAV racks/drawers <NUM> and UAV fast charging stations <NUM>. <FIG>, <FIG>, <FIG> show different arrangements and structures of the UAV racks/drawers <NUM> and the UAV fast charging stations <NUM>. The UAV fast charging stations <NUM> are installed onto the UAV racks/drawers <NUM> so that when the UAV <NUM> returns to the UAS <NUM>, the UAV <NUM> is stored on the UAV racks/drawers <NUM> and being charged by the UAV fast charging station <NUM>. Each UAV <NUM> is provided with at least one UAV rack/drawer <NUM> and one UAV fast charging station <NUM>. Each UAV racks/drawer <NUM> can be stationary or mobile, retractable or non-retractable. Each UAV <NUM> can land on or take off from a retractable UAV rack/drawer <NUM>. The UAS <NUM> is connected to an external power supply so that the UAV fast charging stations <NUM>, the control center <NUM> and other components which need power can work. The external power supply can be electricity grid and/or stand-alone power source. An emergency electricity storage system <NUM> is also provided so that the components in the UAS <NUM> can continue to work if the external power supply is cut off.

<FIG> also show a communication tower <NUM>, a tethered meteorological data sensor <NUM>, a fixed meteorological data sensor <NUM> and a tethering system <NUM> for the tethered meteorological data sensor <NUM>. The communication tower <NUM> can be a steel structure tower that is at least two meters high. Other forms of the communication tower structure are also possible. The wireless communication interface <NUM>, the tethered meteorological data sensor <NUM>, the fixed meteorological data sensor <NUM> and the tethering system <NUM> can be equipped on the communication tower <NUM>. In the embodiments shown in <FIG>, the tethered meteorological data sensor <NUM> is a balloon. As stated above, the tethered meteorological data sensor <NUM> can have other forms. The fixed meteorological data sensor <NUM> is an anemometer in the <FIG>, however, it can be other forms of meteorological data sensor. The tethering system <NUM> is used for fixing the tethered meteorological data sensor <NUM> and control the height of the tethered meteorological data sensor <NUM>. The tethering system <NUM> can be a winch/cable/wire arrangement or other similar setups.

The UAS <NUM> further comprise an external communication device <NUM> which is used to wirelessly communicate with an external apparatus, e.g., a server or an external control center. The external apparatus can send remote instructions to the control center <NUM> of the UAS <NUM> via the external communication device <NUM>. Meanwhile, the control center <NUM> can send data packages to remote users via the external communication device <NUM>. The sent data packages can be calculated meteorological data and other environmental data, or raw data collected by the at least one UAV <NUM>, raw data collected by the tethered meteorological data sensor <NUM>, or raw data collected by the fixed meteorological data sensor <NUM>.

A robotic arm <NUM>, a UAV catapult <NUM> and a runway <NUM> and a damper mat <NUM> are also comprised in the UAS <NUM> in the embodiment shown in <FIG>. The robotic arm <NUM> is a mechanical arm used to pick up, move and place a UAV <NUM> from the UAV racks/drawer <NUM> to the UAV catapult <NUM> or vice versa. The robotic arm <NUM> is also used to pick up, move and place a UAV <NUM> from the runway <NUM> to the UAV racks/drawer <NUM> or vice versa. The robotic arm <NUM> can move along three axes to reach different parts of the UAS <NUM>. The UAV catapult <NUM> is used to launch the UAV <NUM> when it begins to perform flight and can also be other types of UAV launching mechanisms. The runway <NUM> shown here is retracted. The runway <NUM> is used to receive the UAV <NUM> when they return and land. The runway <NUM> can be stationary, mobile, retractable or non-retractable, and can be equipped with retractable runway doors or openings. The damper mat <NUM> is used to reduce vibration to the whole UAS <NUM>, especially the vibration of the control center <NUM>, as well as to prevent damage to the returning/landing UAVs. The UAV <NUM> in <FIG> is fixed wing UAV, non-VTOL.

Referring to the embodiment shown in <FIG>, a take-off & landing area <NUM> is shown. The robotic arm <NUM> is used to pick up, move and place a UAV <NUM> from the UAV racks/drawer <NUM> to the take-off & landing area <NUM> or vice versa. The take-off & landing area <NUM> can be stationary or mobile, retractable or non-retractable, and can be equipped with retractable doors or openings.

Referring to the embodiment shown in <FIG>, a retractable entry/exit <NUM> and a rotating take-off/landing shield <NUM> is shown. The rotating take-off/landing shield <NUM> is used for shielding the UAV from wind fluctuations/gusts in order to facilitate easier and safer take-off and landing.

Claim 1:
A method for obtaining meteorological data by an unmanned aerial system, UAS (<NUM>, <NUM>), the UAS (<NUM>, <NUM>) comprises at least one unmanned aerial vehicle, UAV (<NUM>, <NUM>), a control center (<NUM>, <NUM>) and a wireless communication interface (<NUM>, <NUM>), the at least one UAV (<NUM>, <NUM>) is equipped with a meteorological data sensor (<NUM>) and a flight controller (<NUM>), FC, the at least one UAV (<NUM>, <NUM>) is configured for wireless communication with the control center (<NUM>, <NUM>) via the wireless communication interface (<NUM>, <NUM>) during flight, the method comprising:
sending (<NUM>) flight instruction data, from the control center (<NUM>, <NUM>) to the at least one UAV (<NUM>, <NUM>), instructing the at least one UAV (<NUM>, <NUM>) to perform flight;
performing (<NUM>) flight, by the at least one UAV (<NUM>, <NUM>), according to the flight instruction data;
collecting (<NUM>) raw meteorological data and flight data, by the at least one UAV (<NUM>, <NUM>) during the flight, wherein the raw meteorological data is collected by the meteorological data sensor (<NUM>) and the flight data is collected by the FC (<NUM>), wherein the flight data comprises real time flight related data of the at least one UAV (<NUM>, <NUM>) and the flight data being collected by any one of a position sensor, a motion sensor and/or a combination thereof included in the FC (<NUM>);
transmitting (<NUM>), in real time, the collected (<NUM>) raw meteorological data and the flight data, from the at least one UAV (<NUM>, <NUM>) to the control center (<NUM>, <NUM>), during the flight, via the wireless communication interface (<NUM>, <NUM>) of the UAS (<NUM>, <NUM>);
calculating (<NUM>) meteorological data, in the control center (<NUM>, <NUM>), based on the received raw meteorological data
sending (<NUM>) return instruction data, from the control center (<NUM>, <NUM>) to the at least one UAV (<NUM>, <NUM>), instructing the at least one UAV (<NUM>, <NUM>) to return to the UAS (<NUM>, <NUM>);
returning (<NUM>) the at least one UAV (<NUM>, <NUM>) to the UAS (<NUM>, <NUM>), according to the return instruction data;
characterized in that calculating the meteorological data, in the control center, is based on the received raw meteorological data and the flight data in the transmitting step.