Example methods and systems for contingency landing a UAV are provided, comprising sensors configured to detect a position of the UAV and a command module. The command module receives a mission profile comprising a travel path mapped out in multidimensional space over time from an origin to a destination, a first boundary circumscribing at least a portion of the travel path, a second boundary circumscribing the first boundary, and contingent landing sites. The command module sends instructions to the UAV to fly according to the mission profile and determines a position of the UAV relative to the first and the second boundaries. Responsive to determining that the UAV is positioned at the first boundary, the command module sends instructions to land at a contingent landing site, and responsive to determining that the UAV is positioned at the second boundary, the command module sends instructions to land immediately.

Methods and systems are disclosed for determining a spatial position of an aircraft, without replying on measurements from the Global Positioning System. Various embodiments are described using a single Secondary Surveillance Radar (SSR), and multiple SSRs.

Techniques for allowing a vehicle equipped with at least one radar to take-off and land using radar return images of a landing site. The at least one radar generates radar return image(s) of the landing site, specifically of reflective symbols attached to the landing site, allowing the vehicle to orient itself to the landing site and providing information specific to the landing site. Position and velocity in relation to a landing site can be determined using at least one radar and a guidance and landing system. Using the position and velocity information, the guidance and landing system can guide the vehicle to and from the landing site and/or determine whether an obstacle requires the use of an alternate landing site.

Autoland systems and processes for landing an aircraft without pilot intervention are described. In implementations, the autoland system includes a memory operable to store one or more modules and at least one processor coupled to the memory. The processor is operable to execute the one or more modules to identify a plurality of potential destinations for an aircraft; calculate a merit for each potential destination identified; select a destination based upon the merit; and create a route from a current position of the aircraft to an approach fix associated with the destination that accounts for the terrain characteristic(s) and/or obstacle characteristic(s). The processor can also cause the aircraft to traverse the route, determine a final approach segment associated with the route; identify terrain characteristic(s) and/or obstacle characteristic(s) associated with the final approach segment; and determine an adjusted final approach segment accounting for the terrain characteristic(s) and/or obstacle characteristic(s).

Example methods and systems for contingency landing a UAV are provided, comprising sensors configured to detect a position of the UAV and a command module. The command module receives a mission profile comprising a travel path mapped out in multidimensional space over time from an origin to a destination, a first boundary circumscribing at least a portion of the travel path, a second boundary circumscribing the first boundary, and contingent landing sites. The command module sends instructions to the UAV to fly according to the mission profile and determines a position of the UAV relative to the first and the second boundaries. Responsive to determining that the UAV is positioned at the first boundary, the command module sends instructions to land at a contingent landing site, and responsive to determining that the UAV is positioned at the second boundary, the command module sends instructions to land immediately.

An apparatus interfaces with a light stanchion associated with a runway. The apparatus can include a first interface for attaching to the light stanchion, second interface for attaching to runway light, and a radar reflective member. The radar reflective member can be a corner reflector. The radar reflector can be part of set of reflectors arranged in accordance with visual approach slope indications or precision approach path indications.

The method includes a step of forming, with a radar, a number N of beams of equal angular width that irradiate a runway and a portion of the surroundings of the runway; a step of dividing the zone irradiated by the beams into distance-angle boxes, the beams delineating the boxes anglewise; a step of taking measurements of backscattered power received from distance-angle boxes, the measurements being carried out for a set of pairs of boxes, a pair being composed of two boxes of same distance one of which, called the right box, crosses the right edge (3D) of the runway, and the other of which, called the left box, crosses the left edge (3G); a step of computing, for each pair, the difference in backscattered power between the right box and the left box, the aircraft being aligned with the axis when the difference is zero for at least two pairs of distance-angle boxes.

A system for aiding landing includes a module for computing by extrapolation a trajectory of the aircraft on the basis of its current position, a module for determining whether the extrapolated trajectory cuts the ground ahead of a threshold of the landing runway, a module for measuring a current height of the aircraft above an overflown terrain, a module for determining whether the current height corresponds to a risk height, an alert module for generating an alert only if the two determinations carried out by the two determination modules are positive, and if the aircraft is situated at a distance with respect to the threshold of the landing runway which is less than a predetermined threshold distance.

Disclosed are methods, systems, and non-transitory computer-readable medium for cross-vehicle vehicle navigation. For instance, the method may include: receiving from a detection node, of a plurality of detection nodes, a detection message comprising detected vehicle information for a detected vehicle; obtaining nearby vehicle state information comprising information indicating position, speed, track, heading, or flight path for a plurality of nearby vehicles other than the detected vehicle; performing an analysis of the detected vehicle information and the nearby vehicle state information to confirm a state of the detected vehicle, or determine the detected vehicle to be an intruder vehicle; and transmitting a message to a relevant vehicle from among the plurality of nearby vehicles, based on the analysis.

In some examples, a terrain awareness device includes processing circuitry configured to determine a terrain feature in a travel path of the ownship vehicle. The processing circuitry is also configured to present, on a display, a first graphical user interface indicating the terrain feature. The terrain awareness device also includes a memory configured to store a location of the terrain feature, and the terrain awareness device is configured to receive traffic data from a traffic device. The processing circuitry is further configured to determine a location of a second vehicle based on the traffic data and determine that the ownship first vehicle has been instructed to synchronize with a second vehicle. The processing circuitry is configured to generate a second graphical user interface indicating that the ownship vehicle has been instructed to synchronize with the second vehicle and present the second graphical user interface on the display.