Positioning computer for a satellite having an optical inter-satellite communication system on an anti-Earth face

A positioning computer for a satellite adapted to provide a parameter representing a yaw angle of the satellite, the satellite being intended to move in an orbital plane, the satellite and a sub-solar point of the orbital plane being intended to define a position angle of the satellite as seen from the Earth, the satellite being intended to comprise:

• a body having an Earth face defining an axis Z of the satellite intended to point towards the Earth,
• at least one solar panel mounted rotatably relative to the body around an axis Y of the satellite perpendicular to the axis Z, the satellite defining an axis X perpendicular to the axis Y and the axis Z, the axis X and a reference axis X0 defining the yaw angle, the reference axis X0 being perpendicular to the axis Z, located in the orbital plane and oriented in the direction of an increase in the position angle, and
• at least one first optical system for communicating with another satellite located in the orbital plane, the first optical system being intended to be located on an anti-Earth face of the satellite, opposite the Earth face according to the axis Z, and intended to have a field of view in azimuth around the axis Z, the field of view comprising a first direction parallel to the axis Y and extending to a second direction forming, with the first direction, an angle of 180° minus an obturation angle due to the body,
• the computer being adapted to obtain a parameter representing a solar angle defined by the Sun with the orbital plane, and to perform a calculation of the parameter representing the yaw angle using at least the parameter representing the solar angle,
• characterized in that the computer is configured to use a parameter representing the obturation angle in said calculation.