The invention consists essentially of two light sensors on a spacecraft that are mounted beneath a baffle which divides the light from a light source such as the sun or a star. The divided light reflects off of two reflective surfaces onto the two light sensors. When the spacecraft assumes its normal attitude the baffle divides the light from the light source into two equal parts cuasing the two light sensors to produce equal outputs. An electrical circuit containing the two sensors produces a zero voltage output when the outputs of the two light sensors are equal thereby indicating that the spacecraft is in its normal attitude relative to the light source. While the spacecraft is not in its normal attitude relative to the light source the two light sensors produce unequal outputs causing the electrical circuit to produce an output voltage. The amplitude and polarity of this output voltage are indicative of the attitude of the spacecraft and can be applied to the controls of the spacecraft to return it to its normal attitude.
A sun-sensing guidance system (10) for high-altitude aircraft (A) characterized by a disk-shaped body (14) mounted for rotation aboard the aicraft in exposed relation to solar radiation and having a plurality of mutually isolated chambers (28a, 28b, 32a, and 32b); each chamber of the plurality being characterized by an opening having a photosensor (34a, 34b, 36a, and 36b) disposed therein and arranged in facing relation with the opening for receiving incident solar radiation and responsively providing a voltage output, said photosensors being connected in paired relation through a bridge circuit (38) for providing heading error signals in response to detected imbalances in intensities of solar radiation incident on the photosensors of either pair of photosensors until a nulled relationship is achieved for the disk (14) to the source of radiation.
A solar energy collection system utilizing a fluid which dissociates endothermically and recombines exothermically is described. The preferred fluid is ammonia. Solar radiation is focussed onto absorber-reaction vessels from many paraboloidal mirrors. Means for electronically controlling the orientation of the mirrors is described. The mirrors may close together to reduce the effects of adverse climatic conditions.
A sensor for detecting the position of the sun in the sky and for use in systems adapted to track the movement of the sun in the sky, said sensor comprising a housing provided with a predetermined opening in the vertical and in the horizontal directions, a member having a reflecting surface at least part of which is of spherical shape, a photosensor adapted to provide an electrical signal when illuminated by rays of the sun reflected from said member with spherical surface, said photosensor being located in said housing or in a separate housing, said element with spherical surface being positioned so that rays of the sun entering said opening are reflected onto said photosensor, means being provided to utilize the resulting signal for locking onto the sun and for tracking its movement; systems for such tracking comprising a plurality of such sensors and means for tracking the sun by equalization of the signals obtained from at least two sensors, each covering a predetermined part of the sky.
A control system for radiation tracking apparatus comprises: A. a shadow box having a window, B. four photo sensors located within the box to receive incident radiation passing through the window, C. first and second sensors respectively having upper and lower locations to provide outputs controlling elevational tracking movement of said apparatus, and D. third and fourth sensors respectively having left and right locations to provide outputs controlling azimuthal tracking movement of said apparatus.
The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxiliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.
