A subpixel precision image matching-aided navigation method

Image matching-aided navigation system has broad application prospects, according to its prominent advantages in autonomy and high precision. In order to meet the demands of real time and accuracy of image aided navigation system, the paper propose a subpixel precision image matching algorithm by using a method called the four-dimension real matrix. At first this paper converts the transformation of aircraft´s position and attitude to transformation of two images. Then an optimal transform matrix which is called a four-dimension real matrix can be obtained by the least square algorithm to fit the two images. At last, the deviations of aircraft´s position and attitude are derived according to the proposed model. Experiments have been conducted and the results show that the time consumption is within a second, translation deviations are within a pixel, and angle deviations are within a degree, which illustrates the good performance of the algorithm and the model. As a conclusion, the algorithm satisfies the requirements of real-time situation and accuracy of the image matching-aided navigation system.