Systems and methods for tracking moving objects in accordance with embodiments of the invention are disclosed. In one embodiment of the invention, an object tracking system comprises a processor, a communications interface, and a memory configured to store an object tracking application. The object tracking application configures the processor to receive a sequence of images; estimate and subtract background pixel values from pixels in a sequence of images; compute sets of summed intensity values for different per frame pixel offsets from a sequence of images; identify summed intensity values from a set of summed intensity values exceeding a threshold; cluster identified summed intensity values exceeding the threshold corresponding to single moving objects; and identify a location of at least one moving object in an image based on at least one summed intensity value cluster.

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.

A propulsion system includes an electric propulsor and a gas turbine engine. The propulsion system also includes an electric machine coupled to a rotary component of the gas turbine engine generating a voltage at a baseline voltage magnitude during operation of the gas turbine engine. An electric communication bus is provided electrically connecting the electric machine to the electric propulsor. The propulsion system additionally includes a means for providing a differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

A system and method for estimating a distance between an aircraft and an object is disclosed. An exterior light of the aircraft transmit a test light signal and a parameter the transmitted test light signal is measured. A sensor receives a reflection of the test light signal from the object and the parameter is measured for the reflection test signal. The distance between the aircraft and the object is estimated using the parameter of the reflection and the parameter of the test light signal. The exterior light is generally a light that is built into the aircraft during aircraft construction while the sensor is retrofitted onto the aircraft.

Apparatus and associated methods relate to ranging an object nearby an aircraft by triangulation of spatially-patterned light projected upon and reflected from the object. The spatially patterned light can have a wavelength corresponding to infrared light and/or to an atmospheric absorption band. In some embodiments, images of the object are captured both with and without illumination by the spatially-patterned light. A difference between these two images can be used to isolate the spatially-patterned light. The two images can also be used to identify pixel boundaries of the object and to calculate ranges of portions of the object corresponding to pixels imaging these portions. For pixels imaging reflections of the spatially-patterned light, triangulation can be used to calculate range. For pixels not imaging reflections of the spatially-patterned light, ranges can be calculated using one or more of the calculated ranges calculated using triangulation corresponding to nearby pixels.

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

A propulsion system includes an electric propulsor and a gas turbine engine. The propulsion system also includes an electric machine coupled to a rotary component of the gas turbine engine generating a voltage at a baseline voltage magnitude during operation of the gas turbine engine. An electric communication bus is provided electrically connecting the electric machine to the electric propulsor. The propulsion system additionally includes a means for providing a differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude.

A gas turbine engine includes a core having a compressor section with a first compressor and a second compressor, and a turbine section with a first turbine and a second turbine. The first compressor is connected to the first turbine via a first shaft and the second compressor is connected to the second turbine via a second shaft. An electric motor is connected to the first shaft such that rotational energy generated by the electric motor is translated to the first shaft. An electric energy storage component is electrically connected to the electric motor, and electrically connected to at least one aircraft taxiing system. The gas turbine engine is configured such that the gas turbine engine requires supplemental power from the electric motor during at least one mode of operations.