The Charles Stark Draper Laboratory, Inc.

Gregory P Blasche

Juha-Pekka J Laine

Benjamin F Lane

Stephen P Smith

Robin Mark Adrian Dawson

Erik L Waldron

Paul A Bohn

Joseph M Kinast

Robin Dawson

Matthew T Jamula

Murali V Chaparala

Eric T Hoke

Daniel M Meiser

William W Whitacre

Michael A Aucoin

John James Boyle

Cort Nolan Johnson

Sean McClain

Jeffrey D Jungemann

Peter A Lewis

Walter D Foley

Jeffrey A Korn

Evan M Lally

Samuel W Harrison

Francis J Rogomentich

Robin M A Dawson

Simone B Bortolami

Robert A Larsen

Matthew T Reaves

Charles Arant

Sandra M Klute

Timothy J McCarthy

Matthew S Bottkol

Marc W McConley

James Donna

William Ostrowski

Bruce Dow

Michael Ricard

Emily H Templeton

Erik Waldron

A distributed navigation system includes navigation platforms, each having a universal navigation processor, relative navigation systems to provide source information to the navigation platforms, navigation filters provided on one or more of the universal navigation processors, and an anchor navigation node disposed on one or more of the navigation platforms to form one or more anchor navigation platforms. Each anchor navigation node includes an inertial navigation system, a clock, and absolute navigation systems, which are used, in combination with source information, to determine navigation information. The anchor navigation platforms provide the navigation information to other navigation platforms. The system further includes a navigation processor system in communication with the universal navigation processors to provide operating information updates to the universal navigation processors and a graphical user interface to display the navigation information to a user and permit the user to review and control the navigation information.

Multi-source distributed navigation system architecture

An image-based navigation system is arranged to obtain a terrain image of a target terrain from one or more image sensors at a low altitude imaging location. The terrain image includes at least one celestial image feature and at least one terrain feature. Map database information stored in at least one hardware memory device is accessed and compared to the at least one celestial image feature and the at least one terrain feature in the terrain image to determine absolute location coordinates of the imaging location.

Stellar-landscape/horizon image navigation

A distributed navigation system architecture includes a plurality of navigation platforms, each having a universal navigation processor configured to communicate with other universal navigation processors, one or more relative navigation systems configured to provide source information to the navigation platforms, an anchor navigation node disposed on one or more of the plurality of navigation platforms in order to form one or more anchor navigation platforms, the anchor navigation node, including an inertial navigation system, a clock, and one or more absolute navigation systems, configured to determine navigation information based on the inertial navigation system, the clock, the one or more absolute navigation systems and optionally the source information, the one or more anchor navigation platforms providing the navigation information to the other navigation platforms, and a navigation processor system in communication with each of the universal navigation processors in order to provide operating information updates to the universal navigation processors.

Methods and apparatus automatically determine a location, such as of an aircraft or spacecraft, by matching images of terrain below the craft, as captured by a camera, radar, etc. in the craft, with known or predicted terrain landmark data stored in an electronic data store. A star tracker measures attitude of the camera. An additional navigation aiding sensor provides additional navigational data. Optionally, a rangefinder measures altitude of the camera above the terrain. A navigation filter uses the attitude, the additional navigational data, and optionally the altitude, to resolve attitude, and optionally altitude, ambiguities and thereby avoid location solution errors common in prior art terrain matching navigation systems.

Star tracker-aided airborne or spacecraft terrestrial landmark navigation system

A digital camera optically couples a monocentric lens to image sensor arrays, without optical fibers, yet shields the image sensor arrays from stray light. In some digital cameras, baffles are disposed between an outer surface of a monocentric lens and each image sensor array to shield the image sensor arrays from stray light. In other such digital cameras, an opaque mask defines a set of apertures, one aperture per image sensor array, to limit the amount of stray light. Some digital cameras include both masks and baffles.

Hemispherical star camera

A visual navigation system includes a compass configured to orient a user in a heading direction, an image sensor configured to capture a series of successive navigation images in the heading direction, one or more of the navigation images having at least two reference markers, data storage memory configured to store the series of successive navigation images, a navigation processor configured to identify at least one principal marker and at least one ancillary marker from the at least two reference markers, the principal marker positioned within a principal angle and the ancillary marker positioned within an ancillary angle, which is greater than the principal angle, and to determine heading direction information based on a position of the at least one principal marker and/or the at least one ancillary marker in the successive navigation images, and a user interface configured to provide the heading direction information to the user.

Camera-based heading-hold navigation

Systems and methods for determining the shape and/or position of an object are described. A fiber optic shape sensor (FOSS) may be used in combination with one or more inertial measurement units (IMUs) to mutually cross-correct for errors in the sensors' measurements of position and/or orientation. The IMU(s) may be attached to the FOSS's optical fiber, such that each IMU measures the orientation of a corresponding portion of the optical fiber. The position and shape of the optical fiber can then be determined based on the measurements obtained from the IMU(s) and the measurements obtained from the FOSS. For example, the FOSS measurements and the IMU measurements can be provided to a state estimation unit (e.g., a Kalman filter), which can estimate the position and/or shape of the optical fiber based on those measurements. In some embodiments, the estimates of position are used for navigation of tethered mobile devices.

Navigation systems and methods using fiber optic shape sensors and localized position sensors

Methods and apparatus automatically determine a location, such as of an aircraft or spacecraft, by matching images of terrain below the craft, as captured by a camera, radar, etc. in the craft, with known or predicted terrain landmark data stored in an electronic data store. A star tracker measures attitude of the camera. Optionally, a rangefinder measures altitude of the camera above the terrain. A navigation filter uses the attitude, and optionally the altitude, to resolve attitude, and optionally altitude, ambiguities and thereby avoid location solution errors common in prior art terrain matching navigation systems.

A star tracker determines a location or orientation of an object, such as a space vehicle, by observing unpolarized light from one or more stars or other relatively bright navigational marks, without imaging optics, pixelated imaging sensors or associated pixel readout electronics. An angle of incidence of the light is determined by comparing signals from two or more differently polarized optical sensors. The star tracker may be fabricated on a thin substrate. Some embodiments have vertical profiles of essentially just their optical sensors. Some embodiments include micro-baffles to limit field of view of the optical sensors.

Star tracker

A chip scale star tracker that couples starlight into a lightguide such that the angle of incidence partially determines the mode of propagation of the starlight in the lightguide. A baffle system integrated with the lightguide prevents propagation of light incident from a predetermined range of angles.

Chip-scale star tracker

A device and method for selectively illuminating and designating multiple targets in the air or on the ground simultaneously. The device comprises a light source, a switching array and a ball lens. Light from the light source is routed through the switching array, which can addressably output multiple light beams simultaneously. The light beams from the switching array illuminate the backside of a low F-number ball lens. The ball lens creates highly collimated output beams independently (and simultaneously) from any of the output source points of the switching array. These output beams can be used to simultaneously designate multiple targets. When the target illuminating device includes an optional detector array, light scattered from targets can be refracted by the balls lens to impinge on the detector array. Signals from the detector array representing the received light beams can be used for target imaging.

Multi-target optical designator

A star camera system that includes an optical system configured to focus radiation from a star to be imaged onto a collector. Specifically, the collector is in the form of an electron bombarded active pixel sensor (EBAPS) configured to provide high gain. The EBAPS comprising a photocathode disposed in a vacuum is configured to release electron into a vacuum when exposed to radiation focused thereon by the optical system. In addition, the EBAPS includes an active pixel sensor anode disposed distant from the photocathode in the vacuum. An electric field is generated by a voltage source to direct electrons from the photocathode to the active pixel sensor anode to thereby generate an image of the star.

Electron-bombarded active pixel sensor star camera

Methods and apparatus ascertain a geographic position based on topographic contours of ocean surfaces. Observed ocean topographic contours are matched to predicted ocean topography and/or ocean topographic information stored in a database. Such systems and methods do not necessarily require INS, GPS, RF beacons, optical beacons or celestial sightings. These systems and methods may be used as references to correct INS. These systems and methods may be used to ascertain a geographic location of an aircraft, spacecraft, watercraft, landcraft (vehicle), person or the like. Similarly, these systems and methods may be used as part of a guidance system for guiding a craft to a destination. These systems and methods may be used in tandem with, or as backups for, other types of navigation or guidance systems or as one input to a navigation filter.

Navigation by ocean surface topography

A star camera system that includes an optical system configured to focus radiation from a star to be imaged onto a collector that is in the form of an electron bombarded active pixel sensor (EBAPS) configured to provide high gain. The EBAPS comprising a photocathode disposed in a vacuum is configured to release electrons into the vacuum when exposed to radiation focused thereon by the optical system. The EBAPS includes an active pixel sensor anode disposed distant from the photocathode in the vacuum. An electric field is generated by a voltage source to direct the electrons from the photocathode to the active pixel sensor anode. Furthermore, the collector is mounted on a translation device configured to move the collector relative to the optical system by a predetermined amount of less than pixel size in the focal plane of the optical system to increase image resolution of a plurality of images.

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Burlington, MA, United States of America

Gregory P Blasche