METHOD FOR ACCURATELY GEOLOCATING AN IMAGE SENSOR INSTALLED ON BOARD AN AIRCRAFT

A method for geolocating an image sensor having an LoS and installed on board an aircraft. The geographical position of the sensor and the orientation of its LoS being approximate, it comprises: a step of creating an opportune landmark comprising the following substeps: an operator locating, on a screen for displaying acquired images, a stationary element on the ground, the axis of a telemeter being indicated in these images by means of a reticle the direction of which represents the LoS; the operator moving the LoS in order to place the reticle on this stationary element; tracking of this stationary element; estimating the approximate geographical position of this stationary element; searching in a terrain DB for the location corresponding to a zone centered on the stationary element; displaying an image of the terrain of this location, the operator locating the stationary element; and the operator pointing to this stationary element in the displayed terrain image, the geographical coordinates pointed to being retrieved from the terrain DB, this stationary element becoming an opportune landmark; and the sensor moving relative to the landmark, a step of accurately locating the sensor, from the geographical coordinates of this landmark and using a Kalman filter supplied with a plurality of measurements of the distance between the sensor and the landmark and with a plurality of measurements of the orientation of the LoS of the sensor toward the landmark, there being one orientation measurement for each telemetry measurement, simultaneously allowing the orientation of the LoS to be accurately estimated.