G01C21/025

ENHANCED STAR TRACKING
20210225011 · 2021-07-22 ·

A system and method for star tracking includes: capturing an image of stars; detecting and selecting visible stars from the captured image; extracting features from the selected stars by forming a convex hull from the selected stars to generate a spherical polygon; computing the area and higher order moments of the spherical polygon; and pattern matching the extracted feature against a database of star catalog. The pattern matching includes matching the area of the spherical polygon to a plurality of polygon areas stored in the database and when the number of the matching candidates is more than one, matching a next extracted higher order moment with a respective higher order moment in the database, and repeating said matching of the next extracted higher order moment until the number of the matching candidates is equal to one.

High precision—automated celestial navigation system
11079234 · 2021-08-03 ·

A dual-band (SWIR/visible) optical system operating based on Angles-Only Navigation technology. The SWIR module is optimized for imaging stars. The visible-light sensor is independently optimized for imaging satellites including GPS satellites at night. Preferred embodiment provides continuous high accuracy geo-position solutions day and night (including through the “midnight hole”, when solar-illuminated Low Earth Orbit (LEO) satellites are not available. Applicants have experimentally validated proposed system by imaging LEO satellites during terminator using a 1-inch diameter telescope and GPS satellites at night during midnight hole using a 5-inch telescope.

Vertical navigation system
11841230 · 2023-12-12 · ·

Aspects of the disclosure are directed to acquiring aligned geographic coordinates of a vertical position. In one aspect, a vertical navigation system includes a light source to generate a source beam; a beam splitter to generate a first and a second source references derived from the source beam; a hollow retroreflector to produce a first and a second vertical references derived from the first and the second source references; an attitude sensor to capture a plurality of reference stars and to measure a first set of angles for the first vertical reference and a second set of angles for the second vertical reference, the first set of angles and the second set of angles are relative to the plurality of reference stars; and a processor to produce the aligned geographical coordinates using the first set of angles, the second set of angles, a gravity vector measurement and a time signal.

CELESTIAL SCHEDULING OF A SMART STREETLIGHT CONTROLLER
20210307146 · 2021-09-30 ·

A method to control a streetlight with a smart streetlight controller, includes isolating a terrestrial position of the smart streetlight controller, isolating a specific date, and calculating, at the smart streetlight controller, a time value associated with an event, such as sunrise or sunset, that is defined by a position of the sun on the specific date. The method further includes generating a streetlight control time by applying an offset to the time value, and executing a streetlight control command, such as a command to turn the streetlight on or off, at the streetlight control time.

Method For Acquiring Images Having Unidirectional Distortion From An Aerial Vehicle For 3d Image Reconstruction
20210195103 · 2021-06-24 ·

A method for capturing images of large target area using a single low FOV high resolution camera mounted on an Aerial Vehicle for 3D reconstruction is disclosed. The camera captures sets of images consisting of a nadir image a plurality of oblique images at predefined waypoints or as the Aerial Vehicle travels along a flight path. Oblique images are captured in two perpendicular directions by tilting camera about a single tilt axis at one time thereby preventing bidirectional distortion of objects in images. Further, first direction and second direction define a quadrant of area below the Aerial Vehicle. Oblique images along two perpendicular directions are captured either by using roll and pitch axes, or by using a single tilt axis and a pan axis of camera control mechanism wherein using pan axis the single tilt axis is reoriented in a perpendicular orientation to capture oblique images in perpendicular direction.

Satellite attitude data fusion system and method thereof

A satellite attitude data fusion system and method is disclosed, applicable to the earth satellite environment to estimate attitude data of the satellite. When the satellite attitude data fusion system of the present invention is used to perform the satellite attitude data fusion method, the first step is to perform a body rates quaternion attitude data processing operation. Then, the next step is to perform an attitude/rates data fusion processing operation, wherein an attitude data fusion algorithm module receives the first IAE result data from the first EKF, and the second JAE result data from the second EKF, and performs an attitude/rates data fusion algorithm in a subsystem level to evaluate an attitude estimation JAE performance.

Orientation and navigation apparatus
11047689 · 2021-06-29 ·

Multiple telescopes of a telescope array are rigidly aligned at predetermined relative orientations to simultaneously image corresponding predesignated celestial objects. Detection of light from the celestial objects collected by the telescopes enables calculation or estimation of orientation of the telescope array with respect to the celestial sphere. That orientation, in combination with a planetary nadir direction, enables estimation or calculation of position of the telescope array relative to a planetary surface. The nadir can be measured by dropping a probe particle through an evacuated chamber onto or through a two-dimensional sensor.

Ultra-compact star scanner

A star scanner is provided that uses miniaturized high-speed electronics and an ultra-compact freeform optical design. The star scanner reduces instrument volume, reduces power consumption, and reduces costs, relative to existing star scanners. The optics can be used with a credit card-like footprint, electronics sensor board with optimally packed electronics.

Star Tracker with Adjustable Light Shield

A navigation system includes a star camera having a field of view. The star camera includes a sun shields that selectively block portions of the star camera's field of view, to prevent unwanted light, such as light from the sun or moon, reaching image sensors of the star cameras. Some sun shields include x-y stages or r-θ stages to selectively position a light blocker to block the unwanted light. Some sun shields use positionable partially overlapping orthogonally polarized filters to block the unwanted light. Some sun shields use counter-wound spiral windows that are selectively rotated to block the unwanted light. Some sun shields a curved surface that defines a plurality of apertures fitted with individual mechanical or electronic shutters.

Star tracker-aided airborne or spacecraft terrestrial landmark navigation system

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.