A method for star extraction from daytime star maps with additional cor-rection of eastern elongation
The daytime star map is characterized by high background noise and low signal-to-noise ratio,which lowers the effi-ciency of traditional star extraction methods.Moreover,robustness of single frame extraction methods is poor due to the nega-tive factors of daytime star map,including star energy weakness,noise sensitivity and star contour irregularity.Therefore,a star extraction method with modification of apparent motion is proposed for daytime infrared star map processing.With appli-cation of camera parameter conversion model,image coordinates of the target star were predicted using the data of station posi-tion,observation time and ephemeris.Further,relative displacements of the star in image sequence were precisely calculated using the exposure intervals,which led to precise register of the image superposition on star area,and finally resulted to accu-rate star extraction.Experimental results show that the success rate of star extraction with the proposed method can reach 100％,which is 163％higher than that of traditional algorithms.Meanwhile,the time consumption was reduced to 23％.Sig-nal-to-noise ratio was also enhanced since the influence of random error was greatly reduced,and the centroid extraction accura-cy was improved by 72％compared to single frame methods.
daytime star mapeastern elongationstar extractioncentroid accuracyastro-geodetic surveyingmultiframe overlay
万方数据
维普
