Disclosed is a compact integrated apparatus of an interferometric radar altimeter (IRA) and a radar altimeter (RA) capable of performing individual missions by altitude, which includes: a plurality of antennas; a signal processing control unit selecting an RA mode at a low altitude and selecting an IRA mode at a high altitude based on a mode threshold and selecting an FMCW waveform at the low altitude and selecting an FM pulse waveform at the high altitude based on a waveform threshold; and a transceiving unit transmitting a signal by a first antenna positioned at an outermost portion among the plurality of antennas and receiving a signal by an nth antenna positioned at another outermost portion among the plurality of antennas in the RA mode and transmitting a signal through the first antenna and receiving signals through the plurality of antennas in the IRA mode.

A method and a device for measuring altitude of an aircraft relative to a point on the ground, said aircraft carrying a radar system comprising a directional antenna to transmit a radio frequency signal along a aiming axis, including. controlling the transmission of a radiofrequency signal along the axis, calculating received powers as a function of radial distance on a sum channel and an elevation deviation channel, calculating tilt angular deviation values, determining an estimator of the radial distance of the aircraft relative to the point on the ground intercepted by the aiming axis as a function of at least one zero crossing of the angular deviation measurement in a selected area of the angular deviation measurement curve, calculating an aircraft altitude relative to said point on the ground as a function of the estimator of the radial distance and the elevation angle of the aiming axis.

A proximity sensor for a Laser Guided Bomb (LGB) is provided. A proximity sensor for a Laser Guided Bomb (LGB) includes: an electronics package unit (EPU) configured to be connected to a front end of a warhead; and at least one sensor separate from the EPU and configured to be connected to a forward adapter that is connected to the front end of the warhead. The at least one sensor is configured to obtain data that is used to determine a height above ground of the LGB. The EPU is configured to compare the determined height above ground to a predefined value. The EPU is configured to generate a detonation signal for the warhead based on the determined height above ground being equal to or less than the predefined value.

A system to provide navigation solutions for vehicle landing guidance comprises onboard aiding sensors, an IMU, a radar altimeter, a map database, and a navigation system including a navigation filter that outputs estimated kinematic state statistics for the vehicle. An onboard processor inputs horizontal and vertical position statistics from the navigation filter into the map database, and computes an estimated ground/object height, ground/object velocity, ground/object acceleration, and error statistics thereof, based on terrain and object map data. The processer includes a radar altimeter inertial vertical loop (RIVL) filter that determines relative vertical acceleration based on a difference between vehicle vertical acceleration and ground/object vertical acceleration; determines relative vertical velocity based on a difference between vehicle vertical velocity and ground/object vertical velocity; performs consistency checks on the relative vertical acceleration and relative vertical velocity; and outputs estimated vehicle vertical position and vertical velocity statistics for compensation of the navigation filter outputs.

A network system can communicate with user and provider devices to facilitate the provision of a network-based service. The network system can identify optimal service providers to provide services requested by users. The network can utilize context data in matching service providers with users. In particular, the network system can determine, based on context data associated with a user, whether to perform pre-request matching for that user. A service provider who is pre-request matched with the user can be directed by the network system to relocate via a pre-request relocation direction. When the user submits the service request after the pre-request match, the network system can either automatically transmit an invitation to the pre-request matched service provider or can perform post-request matching to identify an optimal service provider for the user.

A method, apparatus, and system for managing sensor system for an aircraft. A presence of erroneous sensor data generated by a set of external sensors on an exterior of the aircraft is detected. A set of deployable sensors is deployed in response to the erroneous sensor data being received from the set of external sensors on the exterior of the aircraft when an undesired environmental condition adverse to the set of external sensors on the exterior of the aircraft is absent. Sensor data is received from the set of deployable sensors.

The embodiments described herein provide ranging and location determination capabilities in RF-opaque environments, such as a jungle, that preclude the use of Global Positioning System (GPS) and/or laser ranging systems, utilizing transponders and Global Positioning System (GPS) receivers located on aerial vehicles. The aerial vehicles operate above the RF-opaque environment, and communicate with a ranging device within the RF-opaque environment on frequencies that propagate in the RF-opaque environment. The ranging device transmits RF signals to the transponders, which are received by the transponders and re-broadcasted back to the ranging device on a different frequency. The aerial vehicles also provide their coordinates to the ranging device using their GPS receivers. The ranging device uses information about the transmitted and received RF signals and the GPS coordinates of the aerial vehicles to calculate a perpendicular distance to a property line from the ranging device, and/or to calculate a coordinate location of the ranging device.

An example computing system is configured to: (i) receive, from one or more sensors of a vehicle in motion over a body of water, a set of sensor data, (ii) based on the set of sensor data, determine (a) an instantaneous distance between the vehicle and a surface of the body of water and (b) an instantaneous slope of the surface of the body of water, (iii) based on at least one of the instantaneous distance or the instantaneous slope, determine a statistical representation of the surface of the body of water, and (iv) based on the determined statistical representation of the surface of the body of water, adjust one or more control surfaces of the vehicle to change one or more of a speed, altitude, heading, or attitude of the vehicle.

A low range altimeter (LRA) may include a transmitter, a receiver, at least one antenna, an active leakage cancellation circuit, and a microcontroller unit (MCU). The transmitter may be configured to transmit a first signal (or transmitted signal) via the at least one antenna. The receiver may be configured to receive a second signal (or received signal) via the at least one antenna. The active leakage cancellation circuit may be configured to receive a portion of the transmitted signal from the transmitter, and may be configured to inject the portion of the transmitted signal into the receiver after an adjustment of the portion of the transmitted signal to reduce leakage observed in the received signal. The MCU may be coupled to the transmitter and the receiver, and may be configured to adjust the portion of the portion of the transmitted signal.

Disclosed is a compact integrated apparatus of an interferometric radar altimeter (IRA) and a radar altimeter (RA) capable of performing individual missions by altitude, which includes: a plurality of antennas; a signal processing control unit selecting an RA mode at a low altitude and selecting an IRA mode at a high altitude based on a mode threshold and selecting an FMCW waveform at the low altitude and selecting an FM pulse waveform at the high altitude based on a waveform threshold; and a transceiving unit transmitting a signal by a first antenna positioned at an outermost portion among the plurality of antennas and receiving a signal by an nth antenna positioned at another outermost portion among the plurality of antennas in the RA mode and transmitting a signal through the first antenna and receiving signals through the plurality of antennas in the IRA mode.