3D accuracy display evaluation of the relief elements at the Earth's surface by space remote sensing systems

Abstract

A methodology has been developed for estimating the error of three-dimensional mapping of the elements of the relief of the Earth's surface during its remote sensing by space radio interferometers, the equipment of which is placed on two separate platforms flying in close orbits. Numerical results of statistical analysis of the influence of deviations of interferometer parameters from nominal values on the accuracy of target positioning during the entire period of the platforms' orbits are presented. The first section describes a method for solving the navigation problem of determining the position of the target in interferometric mode with the given values of three vector parameters of the problem (the position of the platform, base and speed of the reference antenna) and four scalar (slant range to the target, Doppler frequency, phase shift and wavelength). The relations for calculating the dependence of the sensitivity of the interferometer on the variations of its parameters are given in the second section. The third section is devoted to solving issues related to the positioning of the target relative to the surface of the geoid. The fourth and fifth sections describe two procedures: setting the targeting vector of the radio interferometer antenna pattern to the Earth's surface and analyzing the orientation and kinematics of its base. The simulation results are presented in the sixth section of the article. Statistical analysis in the given example showed that in order to achieve the submeter accuracy of positioning the elements of the relief of the earth's surface, it is necessary that the errors in setting the parameters of the navigation task to be solved do not exceed: 0,5 m on the slant range, 5 mm on the base, 0,25 m/s on the speed of the support platform and 7º on the phase shift.