Abstract: The subject matter of this specification can be embodied in, among other things, a system that includes a reflective surface configured to reflect light to a target plane and three or more view ports that are optically connected to at least one camera, the view ports arranged in the target plane. A computing system is coupled to the camera and configured to receive image information captured by the view ports. The computing system, based on the image information and a relationship between intensity of light reflected by the reflective surface as captured by a particular view port and a distance of the particular view port to a point on the target plane that is a function of the light reflected from the reflective surface incident on or passing through the target plane, estimates a location on the target plane of the point.

Abstract: An apparatus for positioning an object, for example, a solar energy capture device, can include a frame, the object, a joint, and at least two linear actuators. The joint connects the object to the frame and allows the object to rotate relative to the frame. The first and second linear actuators are coupled to the object. When the first and second actuators are actuated in combination, the object rotates about a pitch axis. When the first and second actuators are actuated differentially, the object rotates about a roll axis.

Abstract: A mirror includes multiple layers, each layer having a first surface and an opposing second surface. A first layer is a cementitious material and a second layer is a material compatible with the cementitious material. A first surface of the second layer is integral to the first layer. The second layer is thinner than the first layer and includes an additive that provides electrical conductivity. A third layer provides a transition between the second layer and a reflective surface. A first surface of the third layer is in direct contact with a second surface of the second layer. A fourth layer provides the reflective surface. A first surface of the fourth layer is in direct contact with a second surface of the third layer. A fifth layer includes a transparent material. A first surface of the fifth layer is in direct contact with a second surface of the fourth layer.

Abstract: Methods and systems for managing heliostat aiming toward a target are described. Solar rays incident on a reflective surface of a heliostat mirror are reflected toward the target. One or more optical signalers are arranged at positions about the target. An optical signal received from one of the one or more optical signalers is detected. An error in an orientation of the reflective surface is determined based on the optical signal.

Abstract: A solar tracker includes a base having an upper surface, a collector support structure having a lower surface adjacent to the upper surface of the base, a conduit in fluidical communication with a space between the upper surface of the base and the lower surface of the collector support structure, a pump for pumping fluid into or out of the conduit, wherein injecting fluid into the conduit forms a fluid layer between the collector support structure and the base, and a solar collector supported by the collector support structure.

Abstract: A system determines a first rank associated with a document and determines a second rank associated with the document, where the second rank is different from the first rank. The system also changes, during a transition period that occurs during a transition from the first rank to the second rank, a transition rank associated with the document based on a rank transition function that varies the transition rank over time without any change in ranking factors associated with the document.

Abstract: A solar energy system drive apparatus includes: a rotor including a first circumferential surface and having a first radial dimension from a center axis of the rotor; a stator that is axially aligned with the rotor about the center axis and includes a second circumferential surface and having a second radial dimension from the center of the rotor, wherein the second radial dimension is different than the first radial dimension; and a plurality of planetary members arranged about the first and second circumferential surfaces of the rotor and stator respectively, wherein each of the planetary members has a stepped circumferential surface comprising a third surface and a fourth surface such that the third circumferential surface is in contact with the first circumferential surface and has a third radial dimension from a central planetary axis of the planetary member.

Abstract: Methods, systems, and apparatus, including computer programs encoded on one or more computer storage devices, for collecting solar energy using heliostats arranged about a collection of solar energy receivers. For each heliostat, estimated efficiencies of the heliostat in directing solar rays to two or more receivers at various times of day are determined. Each heliostat is assigned to direct solar rays to two or more different receivers at two or more different times of day, wherein each heliostat directs solar rays to one receiver at a time and the assigning is based on the determined estimated efficiencies for the heliostat at the various of times of day. In some implementations, the receivers are repositionable.

Abstract: A solar tracker system includes a solar collector, a track, a movable assembly supporting the mirror, the movable assembly including track-traveling mechanism configured to move along the track when actuated by a first actuator to adjust an azimuth of the mirror, and a second actuator to adjust an elevation of the mirror.

Abstract: A heliostat control system includes a heliostat having a reflective surface and at least one reflective element, the reflective surface having a different radius of curvature than the at least one reflective element, a receiver configured to receive sunlight reflected from the reflective surface, and a camera configured to receive sunlight reflected from the at least one reflective element and to generate an image including pixels having a brightness dependent on an orientation of the reflective surface.

Abstract: A solar energy system includes a support member secured to a substantially fixed location; a solar energy member mounted to the support member and including a surface operable to track in response to movement of the Sun; an actuator assembly coupled to the solar energy member and configured to periodically apply a torque at a first frequency to move the solar energy member in response to movement of the Sun; and a damper assembly including a spool, where the damper assembly is configured to reactively release and retract a cable about the spool in response to changes in the steady state load, and maintain the cable at a substantially fixed length released from the spool in response to a torque at a second frequency greater than the first frequency that is intermittently received by the solar energy member.

Abstract: A heliostat system includes a base member adapted to be secured to a fixed surface, a transitional member that is formed as a substantially unitary member and a mirror member. The transitional member is coupled to the base member and to the mirror member. The mirror member includes a support portion coupled to the transitional member and a mirror portion. A first bearing coupling the base member and the transitional member provides relative changes in azimuth between the base member and the transitional member. A second bearing coupling the transitional member and the mirror member provides relative changes in elevation between the transitional member and the mirror member. A drive system rotates the transitional member about the first bearing and the mirror member about the second bearing to change the azimuth and the elevation of the mirror member.

Abstract: An ordering of advertisements requested by an ad consumer is based on scores generated for the ads. In each case, a score may be a function of at least one performance parameter associated with the ad and/or a price parameter associated with the ad. The ad consumer may generate presentation information (e.g., a Web page) including advertisements and non-advertisement content (e.g., search results) by (i) accepting the non-advertisement content and advertisements, each of the advertisements including a score, and (ii) combining the non-advertisement content and the advertisements such that relative placements of the advertisements are based on their associated scores.

Abstract: One embodiment of the present invention provides a system for routing packets in a network. A router may receive a packet at an input port which originated from a source system and which is destined to a destination system. The packet may include a traffic-management field which enables the source system to influence how the packet is routed through the network without requiring the source system to explicitly specify nodes that the packet should traverse. The router can use the traffic-management field to select an output port from a set of output ports of the router that are associated with different paths to the destination system. Since the traffic-management field's value is set by the source system, it enables the source system to influence how the router selects the output port, thereby enabling the source system to influence how the packet is routed through the network.

Abstract: An ordering of advertisements requested by an ad consumer is based on scores generated for the ads. In each case, a score may be a function of at least one performance parameter associated with the ad and/or a price parameter associated with the ad. The ad consumer may generate presentation information (e.g., a Web page) including advertisements and non-advertisement content (e.g., search results) by (i) accepting the non-advertisement content and advertisements, each of the advertisements including a score, and (ii) combining the non-advertisement content and the advertisements such that relative placements of the advertisements are based on their associated scores.

Abstract: A system and method for automatically targeting Web-based advertisements is described. Advertisements are identified relative to a query, wherein identified advertisements describe characteristics relative to at least one of a product and a service. The advertisements are scored according to match between the query and the characteristics of the identified advertisements. At least some of the advertisements are provided as Web-based content.

Abstract: A computer-implemented method and system for advertising that performs the steps of delivering an electronic advertisement comprising one or more menu options and a reference to a network location for retrieving specified content associated with each menu option for inclusion in a first electronic document, receiving a selection of one or more menu options from the electronic advertisement and delivering a subsequent accessible document including content from the referenced network location associated with the menu option selected, the subsequent accessible document including the electronic advertisement.

Abstract: A computer-implemented method of providing advertising to a client includes establishing a billing experience between a client and a provider, providing advertising opportunities to the client on at least one of a continual basis and a periodic basis, evaluating a credit risk associated with the client at least one of periodically and upon occurrence of an event, and modifying the billing experience automatically based on the credit risk associated with the client.

Abstract: A heliostat control system includes a receiver located within a receiver volume and a view port located proximate to the receiver volume. The receiver is configured to receive sunlight reflected from a mirror of a heliostat. The view port is optically connected to a camera, and the camera is configured to generate an image including pixels having a brightness dependent on an orientation of the mirror.

Abstract: A computer-implemented method and system for advertising that performs the steps of delivering an electronic advertisement comprising one or more menu options and a reference to a network location for retrieving specified content associated with each menu option for inclusion in a first electronic document, receiving a selection of one or more menu options from the electronic advertisement and delivering a subsequent accessible document including content from the referenced network location associated with the menu option selected, the subsequent accessible document including the electronic advertisement.