Abstract: A balloon equipped with photovoltaic means exhibiting an active face intended to receive solar rays and comprising an envelope, characterized in that the envelope comprises at least: a first zone transparent to solar rays; a second reflecting zone for said solar rays; a third zone comprising said photovoltaic means, the active face of which is directed toward the inside of said envelope; the second and third zones being positioned and cooperating in such a way as to reflect the solar rays in the direction of said third zone.

Abstract: A balloon comprises an envelope containing a lifting gas and a concentrated solar radiation solar generator. The solar generator includes a reflector, one or two arrays of photovoltaic solar cells forming a first active face directed towards the reflector and a second active face directed towards the exterior of the envelope of the balloon. The reflector, the first active face and the second active face of the array of photovoltaic cells are configured so as to ensure the first active face and the second active face of the array both generate electrical power provided that the rollwise solar misalignment of the reflector is smaller than or equal to 10 degrees in absolute value.

Abstract: A spectral imager or spectrophotometer-type optoelectronic camera including an optical system, a CCD-type set of photosensitive elements (3) at the focus of the optical system, a transparent protective window (5) arranged in front of the sensitive face (4) of the set of photosensitive elements (3), and a spectral disperser (1) allowing spectral analysis of the scene observed by the camera. The sensitive face (4) of the set of photosensitive elements (3) that points toward the protective window is coated with a monolayer or multilayer coating of anti-reflection material (9) whose thickness (e) varies continuously as a function of the wavelength of the light received by the sensitive face, parallel to the dispersion axis of the disperser (A).