A method including obtaining at each of a plurality of nodes navigation data of the node, communicating at each node its navigation data to the other nodes via each node's datalink communication system, receiving at each node navigation data communicated from the other nodes, determining at each node distance range of the node relative to the other nodes for which navigation data was received, determining at each node a constellation of the nodes as a function of the navigation data of the node, the navigation data received from the other nodes, and the distance range of the node relative to the other nodes, accessing formation constraints to form the constellation at each node, calculating at each node first guidance commands to maneuver the node to adjust the constellation to be in compliance with the formation constraints; and navigating each node to execute a maneuver based on the first guidance commands.

A guided munition system includes a munition body including at least one fluid dynamic control for changing course of the munition body in flight. A seeker onboard the munition body is operatively connected to control the at least one fluid dynamic control. The seeker includes a coded aperture imaging device facing outward from the munition body for image based control for guiding the munition body in flight.

A ball joint gimbal (BJG) seeker assembly is provided and includes a back shell, a retaining system disposed to urge the seeker ball toward the back shell and a piezoelectric ultrasonic motor and sensor system arrayed between the seeker ball and the back shell. The piezoelectric ultrasonic motor and sensor system is pre-loaded by the retaining system and configured to controllably drive an angular orientation of the seeker ball.

A guided munition system includes a munition body including at least one fluid dynamic control for changing course of the munition body in flight. A seeker onboard the munition body is operatively connected to control the at least one fluid dynamic control. The seeker includes a coded aperture imaging device facing outward from the munition body for image based control for guiding the munition body in flight.

Optical sensors and particularly gimbaled optical sensors transmit an active signal at a given wavelength(s) and receive passive signals over a range of wavelengths and the active signal in a common aperture. The sensor includes a Tx/Rx Aperture Sharing Element (ASE) configured with a center region that couples the active signal to the telescope for transmission and an annular region that couples the passive emissions and the returned active signal to the detector. A filter wheel may be positioned behind the ASE to present separate passive and active images to the detector. These optical sensors may, for example, be used with guided munitions or autonomous vehicles.

Techniques are provided for determination of a guided-munition orientation during flight based on lateral acceleration, velocity, and turn rate of the guided-munition. A methodology implementing the techniques, according to an embodiment, includes obtaining a lateral acceleration vector measurement and a velocity of the guided-munition, and calculating a ratio of the two, to generate an estimated lateral turn vector of the guided-munition. The method also includes integrating the estimated lateral turn vector, over a period of time associated with flight of the guided-munition, to generate a first type of predicted attitude change. The method further includes obtaining and integrating a lateral turn rate vector measurement of the guided-munition, over the period of time associated with flight of the guided-munition, to generate a second type of predicted attitude change. The method further includes calculating a gravity direction vector based on a difference between the first and second types of predicted attitude change.

Model based inertial navigation for a spinning projectile is provided. In one embodiment, a navigation system comprises: a strapdown navigation processor; a propagator-estimator filter, the processor inputs inertial sensor data and navigation corrections from the filter to generate a navigation solution comprising projectile velocity and attitude estimates; an upfinding navigation aid that generates an angular attitude measurement indicative of a roll angle; and a physics model performing calculations utilizing dynamics equations for a rigid body, the model inputs 1) projectile state estimates from the navigation solution and 2) platform inputs indicative of forces acting on a projectile platform, and outputs a set of three orthogonal predicted translational acceleration measurements based on the inputs; the filter comprises a measurement equation associated with the physics model and the upfinding navigation aid and calculates the navigation corrections as a function of the navigation solution, the predicted translational acceleration measurements, and attitude measurement.

Model based inertial navigation for a spinning projectile is provided. In one embodiment, a navigation system comprises: a strapdown navigation processor; a propagator-estimator filter, the processor inputs inertial sensor data and navigation corrections from the filter to generate a navigation solution comprising projectile velocity and attitude estimates; an upfinding navigation aid that generates an angular attitude measurement indicative of a roll angle; and a physics model performing calculations utilizing dynamics equations for a rigid body, the model inputs 1) projectile state estimates from the navigation solution and 2) platform inputs indicative of forces acting on a projectile platform, and outputs a set of three orthogonal predicted translational acceleration measurements based on the inputs; the filter comprises a measurement equation associated with the physics model and the upfinding navigation aid and calculates the navigation corrections as a function of the navigation solution, the predicted translational acceleration measurements, and attitude measurement.

Systems and methods for a tightly coupled trajectory predictor with constant up-finding are provided. In certain embodiments, a system includes an inertial measurement unit that provides inertial measurements of a vehicle. The system also includes an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up. Further, the system includes one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.

Techniques are disclosed for systems and methods for nested gimbal assemblies. A gimbal system may include a base, a yoke, and a gimbal assembly rotatably connecting the yoke to the base. The gimbal assembly may include a motor, a bearing, and a ferrofluid seal. The motor may be configured to rotate the yoke relative to the base about a rotational axis. The bearing may be seated within the base and permit rotation of the yoke relative to the base about the rotational axis. The ferrofluid seal may be positioned to seal an interface between the yoke and the base. The motor may be positioned within an inner diameter of the bearing. The bearing may be positioned within an inner diameter of the ferrofluid seal.