Synthesis of program angular motions of the Earth remote sensing spacecraft with high spatial resolution

Abstract

The article considers a spacecraft for remote sensing of the Earth with high-resolution or ultra-high-resolution optical-electronic equipment. During the shooting process, the recorded image constantly moves through the photodetector matrix at a non-constant and/or excessive velocity, which is not suitable for this photodetector. The purpose of the article is to synthesize a method for the control of the orientation and stabilization of the remote sensing spacecraft, which will provide a strictly specified velocity of the image motion on the photodetector. It is proposed to find such a law of motion (functional dependences of the angular rate of the remote sensing spacecraft on time), which will allow, when applied in the control loop, to compensate for the image motion velocities that are unsuitable for this photodetector. The method used consists in time differentiation of the fundamental equation of space photogrammetry in the guiding cosines, as well as in differentiation of the matrix of guiding cosines. This provides a transition between the guiding cosines in the space of images and the space of objects. The result obtained in the article is the derived equation of space photogrammetry in kinematic form, as well as the functional dependences of angular rate on time. In the present article, a mathematical model of scanning images of the Earth’s landscapes with the help of remote sensing spacecraft is compiled. The obtained functional dependences can be applied in the development of on-board algorithms for controlling the orientation and stabilization of the remote sensing spacecraft. When implementing orientation and stabilization control in the on-board computer based on the obtained functional dependencies, a strictly specified speed of image movement in the focal plane of the on-board shooting equipment can be provided, and, consequently, the quality of the scanned image is improved by improving the function of transmitting the modulation of the kinematic “smudge” (blurring) of the image.

Keywords

• remote sensing of the earth
• spacecraft
• images of earth landscapes
• mathematical model
• compensation of kinematic image blurring
• angular velocity