整合雷達與光學衛星影像進行三維定位之方法/Method of 3D Positioning by integration of Optical and SAR Images
整合雷達與光學衛星影像進行三維定位之方法 Method of 3D Positioning by integration of Optical and SAR Images
A three-dimensional positioning method includes establishing the geometric model of optical and radar sensors, obtaining rational function conversion coefficient, refining the rational function model and positioning the three-dimensional coordinates. Most of the radar satellite companies and part of the optical satellite only provide satellite ephemeris data, rather than the rational function model. Therefore, it is necessary to obtain the rational polynomial coefficients from the geometric model of optical and radar sensors; followed by refining the rational function model by the ground control points, so that object image space intersection is more serious; and then followed by measuring the conjugate point on the optical and radar images. Finally, the observation equation is established by the rational function model to solve the three-dimensional coordinates. It is obvious from the above results that the integration of optical and radar images does achieve the three-dimensional positioning.
provide a three-dimensional positioning method with the integration of radar and optical satellite images, which can effectively improve the shortcomings of the prior art. The directional information in the optical images and the distance information in the radar images are used to integrate the geometric characteristics of the optical images and the radar images in order to achieve the three-dimensional positioning.
1. A three-dimensional positioning method with the integration of radar and optical satellite images, comprising at least the following steps:
(A) establishing an optical image geometric model: direct georeferencing is used as a basis to establish the geometric model of the optical images;
(B) establishing a radar image geometric model: the geometric model of the radar images is established based on Range-Doppler equation;
(C) obtaining a rational polynomial coefficients: based on the rational function model, optical satellite images are subject to back projection according to virtual ground control points in a geometric model for optical images; an image coordinate corresponding to the virtual ground control points is obtained by using collinear conditions; from the geometric model for radar images, radar satellite images are subject to back projection according to the virtual ground control points; according to the distance and the Doppler equation to obtain an image coordinate corresponding to the virtual ground control points; and rational polynomial coefficients for the optical images and the radar images are generated to establish a rational function model;
(D) refining the rational function model: in the rational function model, the image coordinate is converted to a rational function space and calculated as a rational function space coordinate; the rational function space coordinate and the image coordinate according to the ground control points are used to obtain affine conversion coefficient; after the completion of the linear conversion, the system error correction is finished; and by means of least square collocation, the partial compensation is executed for amendments so as to eliminate systematic errors; and
(E) three-dimensional positioning: after the rational function model is established and refined, conjugate points are measured from the optical images and radar images; those conjugate points are put into the rational function model to establish an observing equation of three-dimensional positioning; and positioning a target at a three-dimensional spatial coordinate can be finished by least square method.