A horizontal acoustic vector sensor system described herein includes a housing which has a gimbal assembly therein which is attached to a sensor assembly which has multiple pairs of seismometers that arranged orthogonally to one or more neighboring pairs of seismometers, along an approximately horizontal axis. The gimbal assembly with sensor assembly are enclosed within the housing by an endcap which includes an electronics assembly. The multiple pairs of seismometers are wired to the electronics assembly through a slip-ring which allows for movement of the gimbal assembly without entangling the wires. The horizontal acoustic vector sensor system further includes at least one omni-directional hydrophone integrated into the endcap.

This invention relates to a method of improving performance of a SODAR system adapted to locate discontinuities in the atmosphere by transmitting pulse compression signals such as a plurality of acoustic chirps, the method comprising: transmitting one or more acoustic chirps; receiving one or more acoustic echoes of the transmitted chirps; processing the acoustic echoes to provide an indication of the discontinuities in the atmosphere, thereby providing a wind shear profile; processing the wind shear profile to correct systematic Doppler errors associated with the acoustic echoes by: subtracting a first measured wind speed from the wind shear profile; and adding a second measured wind speed to the wind shear profile.

This invention relates to a method of improving performance of a SODAR system adapted to locate discontinuities in the atmosphere by transmitting pulse compression signals such as a plurality of acoustic chirps, the method comprising: transmitting one or more acoustic chirps; receiving one or more acoustic echoes of the transmitted chirps; processing the acoustic echoes to provide an indication of the discontinuities in the atmosphere, thereby providing a wind shear profile; processing the wind shear profile to correct systematic Doppler errors associated with the acoustic echoes by: subtracting a first measured wind speed from the wind shear profile; and adding a second measured wind speed to the wind shear profile.

A method for determining airspeed of an aircraft that includes determining a rotor model relating a power coefficient of a propeller of the aircraft to an axial inflow velocity through the propeller as a function of a set of rotor operating parameters; determining the set of rotor operating parameters by sampling an electronic control signal associated with an electric motor actuating the propeller; computing the axial inflow velocity through the propeller based on the set of rotor operating parameters using the rotor model; and determining the airspeed based on the axial inflow velocity.

A method for determining airspeed of an aircraft that includes determining a rotor model relating a power coefficient of a propeller of the aircraft to an axial inflow velocity through the propeller as a function of a set of rotor operating parameters; determining the set of rotor operating parameters by sampling an electronic control signal associated with an electric motor actuating the propeller; computing the axial inflow velocity through the propeller based on the set of rotor operating parameters using the rotor model; and determining the airspeed based on the axial inflow velocity.

In one illustrative configuration, an air quality monitoring system may enable wide-scale deployment of multiple air quality monitors with high-confidence and actionable data is provided. Further, the air quality monitoring system may enable identifying a target emission from a plurality of potential sources at a site based on simulating plume models. The simulation of plume models may take into consideration various simulation parameters including wind speed and direction. Further, methods of determining a plume flux of a plume of emissions at a site, and methods of transmitting data from an air quality monitor are disclosed.

A wind direction and a wind speed are readily and accurately estimated at a desired position without using a wind direction and velocity sensor. Movement instruction means of a wind estimation system instructs an unmanned aerial vehicle (UAV), which includes a sensor unit that detects information about a position change, to move. Fall control means causes the UAV to free fall after the UAV is moved according to the instruction of the movement instruction means. Estimation means estimates at least one of a wind direction and a wind speed at a fall position based on the information about the position change detected by the sensor unit during a fall of the UAV.

A wind direction and a wind speed are readily and accurately estimated at a desired position without using a wind direction and velocity sensor. Movement instruction means of a wind estimation system instructs an unmanned aerial vehicle (UAV), which includes a sensor unit that detects information about a position change, to move. Fall control means causes the UAV to free fall after the UAV is moved according to the instruction of the movement instruction means. Estimation means estimates at least one of a wind direction and a wind speed at a fall position based on the information about the position change detected by the sensor unit during a fall of the UAV.

A risk determining method and apparatus are disclosed. The risk determining method includes obtaining a plurality of sets of elevation-velocity data, determining a diffusion prediction coefficient based on the obtained sets of elevation-velocity data, determining at least one of a volatilization factor (VF) or a particulate emission factor (PEF) based on the determined diffusion prediction coefficient, and determining a risk from an inhalation exposure based on the at least one of the VF or the PEF.

A risk determining method and apparatus are disclosed. The risk determining method includes obtaining a plurality of sets of elevation-velocity data, determining a diffusion prediction coefficient based on the obtained sets of elevation-velocity data, determining at least one of a volatilization factor (VF) or a particulate emission factor (PEF) based on the determined diffusion prediction coefficient, and determining a risk from an inhalation exposure based on the at least one of the VF or the PEF.