Three-dimensional positioning method

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.