A system for determining airborne light detection and ranging (lidar) installation angles includes an airborne platform, a light detection and ranging (lidar) apparatus, a navigation system and a processor. The airborne platform performs a calibration flight in an orbit. The lidar apparatus is installed on the airborne platform for wind-velocity measurement. The navigation system is on board the airborne platform and measures motion data associated with movements of the airborne platform and generates a navigation signal. The processor determines in real time one or more installation angles of the lidar apparatus on the airborne platform to improve accuracy of the wind-velocity measurement.

Disclosed are methods of navigation by satellite positioning system without the aid of any ground-based facilities or supplemental data. An aircraft can autonomously define an approach path for navigation to a landing location by surveying a desired landing area prior to flight, and spatially and mathematically defining a vertical and inclined horizontal plane of interest, along with the target landing point. Also disclosed is a system for using satellite-derived position and velocity information to navigate an aircraft without ground-based facilities or data. Methods defining the approach path through alternate vertical geometries of interest are also disclosed.

An automatic landing system contains a control device for providing positional data for controlling an aircraft, a first position or range measuring device for detecting first positional data of the aircraft, a second position or range measuring device for detecting second positional data of the aircraft, and a sensor device for detecting sensor data from which a direction in which a landmark is located and/or a distance of the landmark to the aircraft can be determined. The control device may be configured to generate, based on the first positional data, a first hypothesis for the direction and distance of the landmark and, based on the second positional data, a second hypothesis for the direction and distance of the landmark. Moreover, the control device may be configure to confirm or discard the first hypothesis and the second hypothesis, respectively, using the sensor data detected by the sensor device.

Disclosed are methods, systems, and non-transitory computer-readable medium for landing a vehicle. For instance, the method may include: before a descent transition point, receiving from a service a landing zone confirmation including landing zone location information and an indication that a landing zone is clear; determining a landing flight path based on the landing zone location information; and upon the vehicle starting a descent to the landing zone using the landing flight path: receiving landing zone data from at least one of a radar system, a camera system, an altitude and heading reference system (AHRS), and a GPS system; performing an analysis based on the landing zone data to determine whether an unsafe condition exists; and based on the analysis, computing flight controls for the vehicle to continue the descent or modify the descent.

Systems and methods of precision landing in adverse conditions are provided. In one embodiment, a precision landing system comprises a vehicle including: a receiver configured to receive position information for structures and a landing zone of a landing site and a processor coupled to a memory, the memory includes three-dimensional geometric structural information for a landing site. The processor configured to: receive the position information from the receiver; assign geographical coordinates to the three-dimensional geometric structural information using the position information for the structures and the landing zone of the landing site; send the three-dimensional geometric structural information and graphical rendering information to a display device. The vehicle further includes a display device, wherein the display device is configured to render and display a three-dimensional representation of the landing site in real-time based on the three-dimension geometric structural information and the graphical rendering information from the processor.

Systems and methods of precision landing in adverse conditions are provided. In one embodiment, a precision landing system comprises a vehicle including: a receiver configured to receive position information for structures and a landing zone of a landing site and a processor coupled to a memory, the memory includes three-dimensional geometric structural information for a landing site. The processor configured to: receive the position information from the receiver; assign geographical coordinates to the three-dimensional geometric structural information using the position information for the structures and the landing zone of the landing site; send the three-dimensional geometric structural information and graphical rendering information to a display device. The vehicle further includes a display device, wherein the display device is configured to render and display a three-dimensional representation of the landing site in real-time based on the three-dimension geometric structural information and the graphical rendering information from the processor.

A radio signal processing system includes a first antenna; a second antenna; a first receiver communicatively coupled to the first antenna; a second receiver communicatively coupled to the second antenna; a first processing unit communicatively coupled to the first receiver and configured to receive a first signal from at least one of the first antenna and the second antenna when the system is operating in a first mode; a second processing unit communicatively coupled to the second receiver and configured to receive a second signal from the second antenna when the system is operating in a first mode; and wherein the first processing unit is further configured to receive a third signal from both the first antenna and the second antenna when the system is operating in a second mode.

A radio signal processing system includes a first antenna; a second antenna; a first receiver communicatively coupled to the first antenna; a second receiver communicatively coupled to the second antenna; a first processing unit communicatively coupled to the first receiver and configured to receive a first signal from at least one of the first antenna and the second antenna when the system is operating in a first mode; a second processing unit communicatively coupled to the second receiver and configured to receive a second signal from the second antenna when the system is operating in a first mode; and wherein the first processing unit is further configured to receive a third signal from both the first antenna and the second antenna when the system is operating in a second mode.

The invention relates to a method and system for the validation of satellite-based positioning. The system comprises a radio navigation device (10) installed on board a mobile carrier (2), including a satellite geo-positioning device (12) able to receive a composite radio signal including a plurality of radio navigation signals each transmitted by a transmitting satellite and including time-synchronization and position-reference information, the radio navigation device being able to carry out processing of the received radio navigation signals to calculate first navigation information including information on the geographical position, speed and time of the carrier.

The radio navigation device (10) is capable of transmitting baseband digitized signals (IF.sub.1, . . . , IF.sub.N) from radio navigation signals received at the reference processing station (16), the reference processing station (16) is capable of carrying out processing (29) similar to the processing (20), carried out by said radio navigation device (10), of the digitized signals (IF.sub.1, . . . , IF.sub.N) in order to calculate second navigation information, and the system comprises means (22, 42) for validating the first navigation information in accordance with the second navigation information calculated by the reference processing station (16).

A method comprises computing position information from a global navigation satellite system (GNSS); computing an altitude measurement based on retrieved information from a vertical position sensor; determining a vertical protection level (VPL) associated with the position information; splitting the VPL into an upward VPL component and a downward VPL component; determining a vertical alert limit (VAL) associated with the altitude measurement; and splitting the VAL into an upward VAL component and a downward VAL component. The method optimizes an integrity budget allocation between the upward and downward VPL components. The method then recomputes the upward and downward VPL components given the optimized integrity budget allocation.