217 results about "Star chart" patented technology

An automatic celestial navigation system for navigating both night and day by observation of K-band or H-band infrared light from multiple stars. In a first set of preferred embodiments three relatively large aperture telescopes are rigidly mounted on a movable platform such as a ship or airplane with each telescope being directed at a substantially different portion of sky. Embodiments in this first set tend to be relatively large and heavy, such as about one cubic meter and about 60 pounds. In a second set of preferred embodiments one or more smaller aperture telescopes are pivotably mounted on a movable platform such as a ship, airplane or missile so that the telescope or telescopes can be pivoted to point toward specific regions of the sky. Embodiments of this second set are mechanically more complicated than those of the first set, but are much smaller and lighter and are especially useful for guidance of aircraft and missiles. Telescope optics focus (on to a pixel array of a sensor) H-band or K-band light from one or more stars in the field of view of each telescope. Each system also includes an inclinometer, an accurate timing device and a computer processor having access to catalogued infrared star charts. The processor for each system is programmed with special algorithms to use image data from the infrared sensors, inclination information from the inclinometer, time information from the timing device and the catalogued star charts information to determine positions of the platform. Direction information from two stars is needed for locating the platform with respect to the celestial sphere. The computer is also preferably programmed to use this celestial position information to calculate latitude and longitude which may be displayed on a display device such as a monitor or used by a guidance control system. These embodiments are jam proof and insensitive to radio frequency interference. These systems provide efficient alternatives to GPS when GPS is unavailable and can be used for periodic augmentation of inertial navigation systems.

An automatic celestial navigation system for navigating both night and day by observation of K-band or H-band infrared light from multiple stars. A preferred embodiment uses three telescopes with each of the three telescopes rigidly mounted with respect to each other and rigidly mounted on a movable platform such as a ship or airplane with each telescope being directed at a substantially different portion of sky. Telescope optics focuses, onto the pixel array of a sensor, H-band or K-band light from stars in the field of view of each telescope. The system also includes an inclinometer, an accurate timing device and a computer processor having access to cataloged infrared star charts.

The invention belongs to the field of spaceflight technique, relating to the improvement of the star map identification method. The method has the steps of: 1. constructing and storing angular spacing-corresponding star pair database; 2. selecting observing triangle; 3. identifying the triangle; 4. verifying. The invention saves memory space, needs no accurate brightness information, and has stronger error recovery ability and very high searching and identifying speeds.

A method of automatically tracking and photographing a celestial object, includes inputting latitude information, photographing azimuth angle information and photographing elevation angle information of a photographic apparatus; inputting star map data of a certain range including data on a location of a celestial object from the latitude information, the photographing azimuth angle information and the photographing elevation angle information; calculating a deviation amount between a location of the celestial object that is imaged in a preliminary image obtained by the photographic apparatus and the location of the celestial object which is defined in the input star map data; correcting at least one of the photographing azimuth angle information and the photographing elevation angle information using the deviation amount; and performing a celestial-object auto-tracking photographing operation based on the corrected at least one of the photographing azimuth angle information and the photographing elevation angle information.

An automatic celestial navigation system for navigating both night and day by observation of K-band or H-band infrared light from multiple stars. One or more telescopes mounted on a movable platform such as a ship or airplane and directed at a substantially different portion of sky. Telescope optics focus (on to a pixel array of a sensor) H-band or K-band light from one or more stars in multiple telescopic fields of view. Each system also includes a GPS sensor and a computer processor having access to catalogued infrared star charts. The processor for each system is programmed with special algorithms to use image data from the infrared sensors, position and timing information from the GPS sensor, and the catalogued star charts information to determine orientation (attitude) of the platform.

The double-view field star sensing detector and its star chart distinguishing method belongs to the field of posture sensor technology. The double-view field star sensing detector has one semi-transparent mirror in angle of 45 deg to the main optical axle installed before the lens system of common star sensing detector, and two lens hoods in the two incident light directions of the semi-transparent mirror to avoid spatial stray light interference. The light rays of the two view fields are transmitted and reflected separately in the semi-transparent mirror, passed through the same lens system and imaged in the same photosensitive detector. Compared with common single view field star sensing detector, the double-view field star sensing detector has higher precision, high chip utilization, small volume, low power consumption, easy installation and use, and other features. In addition, the corresponding star chart distinguishing method is also disclosed.

The invention provides an inertia / astronomical integrated navigation method based on residual compensation multi-rate CKF, and the method comprises the steps: firstly building a state and measurementequation of an integrated navigation system, and recording the state quantity of the system; carrying out deblurring processing on the trailing star map by utilizing an SRN-based image deblurring method; taking the deblurred attitude information as a part of observed quantity of volume Kalman filtering based on residual compensation, and jointly inputting the deblurred attitude information and recorded system state quantity into a filter for filtering estimation; correcting the output delay of the star sensor through residual compensation to realize data synchronization; introducing a long-short-term memory neural network estimator into a multi-rate cubature Kalman filter based on residual compensation to serve as a filter sub-module, and achieving same-frequency output of an inertial sensor and a star sensor. And the optimal estimation of the inertial / astronomical integrated navigation attitude is realized based on the compensated data and model. According to the invention, the autonomy of navigation and positioning can be effectively improved, and the navigation precision is further improved.

The invention belongs to the technical field of astronomical navigation, and relates to a multi-star map fused astronomical positioning method. Experimental verification depends on a digital zenith instrument, and a hardware system of the digital zenith instrument comprises an optical imaging system, a high-precision inclinometer and a precision leveling device. The software system comprises starmap processing, zenith instrument positioning calculation and inclination angle compensation. The method is characterized by comprising three steps of fixed star image point track model construction,multi-star map fusion and fused star map positioning. Compared with the prior art, by adopting the method for positioning, when regional star point missing exists in a small number of star maps due tothe fact that star map shooting is affected by external uncertain factors, it can be guaranteed that the digital zenith instrument has high positioning precision through multi-star map fusion.

The invention discloses a space debris real-time astronomical positioning and photometry method based on pointing error automatic measurement. The method comprises the following steps: obtaining a fixed star and a space debris star image; performing fixed star retrieval; generating a theoretical star map; generating an actually measured star map; matching the theoretical star map with the actuallymeasured star map; pointing and image plane rotation measurement; optimizing a negative film model; calculating a photometric model; and performing space debris astronomical positioning and photometry. According to the invention, the negative film model can be automatically optimized according to the observation view field; according to the given time and the image center pointing on the image, the image center pointing and the image plane rotation angle are automatically measured, automatic matching of fixed star theoretical coordinates and actually measured coordinates is achieved, automatic matching of gray level of the fixed star on the image and theoretical star magnitude of the fixed star is achieved, and therefore real-time astronomical positioning and photometry of space debris are achieved.

The embodiment of the invention discloses a method, a device and a system for detecting an inter-satellite angular position error of a high-resolution dynamic star simulator. A star point display device displays a star point image according to star map data generated by a star map generation processor based on a star catalogue database and the position information, light emitted by the display star point is converged through a star simulator optical lens to form parallel light, and the parallel light is projected into a high-precision theodolite eyepiece located at a rear end of the star simulator optical lens to be imaged; a star point image acquisition device is used for acquiring a crosshair displayed by a high-precision theodolite and a to-be-measured star point image in real time, theobtained information is sent to an inter-satellite angular position error detection processor so as to enable the inter-satellite angular position error detection processor to process the received image and calculate a position difference value of the center point positions of the crosshair and the to-be-measured star point image in the same direction, and lastly, an inter-satellite angular position error value is calculated according to a corresponding high-precision theodolite dial display numerical value when each position difference value is 0. The method is advantaged in that test precision and detection efficiency of the inter-satellite angular position error are effectively improved.