Study On Celestial Navigation By Three Fields Of View Star Recognition

This paper studies celestial fix by the three fields of view of the opticalmeasurement. It is classified as celestial navigation techniques. According to theoptical measurement method, it obtains the stars' position vector in the carrierreference system to calculate the carrier's position and direction information.By analyzing the distribution of stars, atmospheric properties, CCDcharacteristics, it founds that navigation efficiency by using near-infrared banddevices is higher than visual band at daytime. Simulation experiments show that it isfeasible to detect stars by H-band device at daytime in navigation, and the stellardistribution of the probability of three optical apertures is extremely higher than oneoptical aperture's. The simulation results can guide the design of optical systemparameters. Paper presents an algorithm to extract the star catalog and staridentification database which are used in three optical aperture navigation device.The thesis provides automatic efficient and robust star pattern recognitionmethods used in three optical aperture navigation device. Identification methodextracts the stellar points from the acquired images, and then the star positions areconverted from the image plane coordinate system to the body coordinate system toperform the three optical aperture stars identification; this can get higher recognitionefficiency. There are three recognition modes. According to the different initialconditions, the recognition modes are classified as the entire celestial sphere identification, local identification, and tracking identification. If geographicinformation and direction information are unknown, system performs the entirecelestial sphere identification mode. If geographic information is known, but notdirection information, then system performs local identification mode. If geographicinformation and direction information are all known, system performs the trackingidentification mode. Stars in three aperture optical fields are identified as a whole inmulti-pattern recognition method, which combines the information of the initial stateto identify; this improves the recognition efficiency of the system and navigationefficiency. Analysis showed that the prerequisite probability of the identification ofthree apertures is higher than the single field of view's. The correct rate of localidentification is3.7times the entire celestial sphere.A navigation information element is constructed by an identified stellar. Thisthesis presents a concise mathematical model to determine the location and directionof the carrier, and then verifies the correctness of this navigation model bysimulation tests. Spherical astronomy circle model is established in spacerectangular coordinate system. Model by solving the two or more observationsspherical astronomy circle intersection determines the carrier geographical locationand the carrier position. And then an optimization solution model is proposed inorder to get an optimal result. Compared with the traditional solution model, theconcept of this method is clear, concise.Star chart calculation and navigation simulation software simulation analysisshows that, the average positioning error of three aperture optical navigation deviceis257.9m; the orientation error was12.4asc. Three fields of view celestial fix is areliable and effective.