Method for acquiring images of the surface of the Earth, characterised in that it comprises steps of: - placing of a first aerial or space platform in a stationary position above said surface of the Earth or moving at a speed less than 200km/h above said surface of the Earth, said first platform comprising a first image acquisition system with a field of view covering a zone, called zone of interest, of said surface of the Earth, - placing of a second aerial or space platform in a stationary position above said surface of the Earth or moving at a speed less than 200km/h above said surface of the Earth, said second platform comprising a second image acquisition system with a narrower field of view and of better resolution than the first image acquisition system, the field of view of said second image acquisition system being orientable such that the field of regard of said second image acquisition system covers said zone of interest, - implementing an observation cycle comprising steps of: a/ acquiring an image of said zone of interest by said first image acquisition system, b/ partitioning of the image thus acquired, called preliminary image, in mesh units each corresponding to a sector of said zone of interest capable of being included in the field of view of the second image acquisition system, c/analysing said preliminary image, to detect the potential presence of marks (42, 42') representative of unwanted elements in or above the zone of interest, d/ identifying mesh units of said preliminary image comprising no mark representative of unwanted elements, said mesh units corresponding to so-called favourable sectors of said zone of interest, e/ and, if applicable, acquiring an image, called final image, of favourable sector(s) by said second image acquisition system, - and, if a predetermined rate of sectors of the zone of interest for which a final image has been acquired by the second image acquisition system has not been achieved, repeat(s) of the observation cycle until said rate is achieved. - placing of a first aerial or space platform in a stationary position above said surface of the Earth or moving at a speed less than 200km/h above said surface of the Earth, said first platform comprising a first image acquisition system with a field of view covering a zone, called zone of interest, of said surface of the Earth, - placing of a second aerial or space platform in a stationary position above said surface of the Earth or moving at a speed less than 200km/h above said surface of the Earth, said second platform comprising a second image acquisition system with a narrower field of view and of better resolution than the first image acquisition system, the field of view of said second image acquisition system being orientable such that the field of regard of said second image acquisition system covers said zone of interest, - implementing an observation cycle comprising steps of: a/ acquiring an image of said zone of interest by said first image acquisition system, b/ partitioning of the image thus acquired, called preliminary image, in mesh units each corresponding to a sector of said zone of interest capable of being included in the field of view of the second image acquisition system, c/analysing said preliminary image, to detect the potential presence of marks (42, 42') representative of unwanted elements in or above the zone of interest, d/ identifying mesh units of said preliminary image comprising no mark representative of unwanted elements, said mesh units corresponding to so-called favourable sectors of said zone of interest, e/ and, if applicable, acquiring an image, called final image, of favourable sector(s) by said second image acquisition system, a/ acquiring an image of said zone of interest by said first image acquisition system, b/ partitioning of the image thus acquired, called preliminary image, in mesh units each corresponding to a sector of said zone of interest capable of being included in the field of view of the second image acquisition system, c/analysing said preliminary image, to detect the potential presence of marks (42, 42') representative of unwanted elements in or above the zone of interest, d/ identifying mesh units of said preliminary image comprising no mark representative of unwanted elements, said mesh units corresponding to so-called favourable sectors of said zone of interest, e/ and, if applicable, acquiring an image, called final image, of favourable sector(s) by said second image acquisition system, - and, if a predetermined rate of sectors of the zone of interest for which a final image has been acquired by the second image acquisition system has not been achieved, repeat(s) of the observation cycle until said rate is achieved.