Method for determining and transmitting slant visibility range information, and aircraft comprising a system for measuring a slant visibility range

A method for determining, by way of an aircraft, and for transmitting, by way of a ground station, slant visibility range information for a runway at a predetermined decision altitude, defined in visual approach rules for the runway, the runway comprising a plurality of visual runway references placed on the ground, the method comprising successive steps of:

• a step of acquiring, by way of a first aircraft equipped with a system for measuring a value of the slant visibility range, an image of a surrounding scene located outside and ahead of the aircraft, the scene possibly containing at least one visual runway reference, the image being acquired at the decision altitude and when approaching the runway;
• a step of analyzing the image, implemented by the first aircraft, in which the system for measuring the value of the slant visibility range implements image processing algorithms to detect visual runway references in the image and measure a distance between the aircraft and each detected runway reference;
• a step of transmitting slant visibility range information associated with the runway to the ground station, implemented by the first aircraft, the information comprising a distance between a visual runway reference and the aircraft measured in step of analyzing if at least one runway reference has been detected, or if not information according to which no visual runway reference was able to be detected;
• and
• a step of transmitting, by way of the ground station, the slant visibility range information associated with the runway to at least one second aircraft in flight.