Abstract: Systems and techniques for laser metrology. Two or more fanned probe beams are scanned relative to a surface including one or more targets. A position detection module receives return beam information from the fanned probe beams, and determines a position of at least a first target of the one or more targets based on the return beam information.

Abstract: Systems and techniques for laser metrology. A system may include a laser source and a fanning apparatus configured to generate a fanned laser beam. The fanned laser beam may be scanned across the surface of an object, and may reflect off a plurality of targets positioned on the surface. A position detection module may determine a position of the metrology targets based on the reflected beam.

Abstract: A system and associated method for compensating for thermal deformation of a spaced-based structure having a spacecraft payload. The system including a beacon source coupled to a first spacecraft for transmitting a first signal and a beacon sensor coupled to a second spacecraft for receiving the first signal and providing measurement data derived from the first signal. At least one attitude sensing device is coupled to the second spacecraft for determining estimated spacecraft attitude data for the second spacecraft. A processor on the second spacecraft is configured to process ephemeris data of the first and second spacecraft, beacon measurement data, estimated spacecraft attitude data, and gimbal angular position data to estimate spacecraft structural deformation.

Abstract: Various embodiments of the present invention are directed to precision control system for spacecraft gimbaled payloads. Embodiments of the invention provide an innovative technique of calibrating gimbals disturbances to directly canceling gimbal control disturbances. Such a calibration system includes a receiver for receiving telemetry data for pointing a payload, a processor for calculating a disturbance parameter vector for a gimbal disturbance model with the telemetry data and a transmitter for transmitting the disturbance parameter vector to compensate for pointing error when applied in pointing the payload. The gimbal disturbance model comprises a harness stiffness term, a disturbance harmonics term and at least one friction hysteresis term. The telemetry data may be time matched prior to calculating the disturbance parameter vector.

Abstract: A system and associated method for compensating for thermal deformation of a spaced-based structure having a spacecraft payload. The system including a beacon source coupled to a first spacecraft for transmitting a first signal and a beacon sensor coupled to a second spacecraft for receiving the first signal and providing measurement data derived from the first signal. At least one attitude sensing device is coupled to the second spacecraft for determining estimated spacecraft attitude data for the second spacecraft. A processor on the second spacecraft is configured to process ephemeris data of the first and second spacecraft, beacon measurement data, estimated spacecraft attitude data, and gimbal angular position data to estimate spacecraft structural deformation.

Abstract: In accordance with an embodiment of the present invention, a resolver system has at least one resolver and at least one amplifier in electrical communication with each resolver. A reference circuit is in electrical communication with the amplifiers. The reference circuit provides reference signals to the amplifiers. A non-linearity calibration and compensation circuit in communication with each amplifier uses the amplified reference signals to provide scale factors, so as to enhance a precision of the resolver system.

Abstract: A method and apparatus for controlling a gimbaled platform. The method comprises the steps of computing an acquisition phase gimbal angle rate command ?cmd—Acq from a measured LOS angle error ??LOS for an initial control period T while computing an estimated LOS angle rate {circumflex over (?)}LOS, computing a tracking phase gimbal angle rate command ?cmd—Trk using a controller having an output initialized with the estimated LOS angle rate {circumflex over (?)}LOS, and commanding the gimballed platform according to an angle rate command ?cmd, wherein the angle rate command ?cmd is the acquisition phase angle rate command ?cmd—Acq during the initial control period T and the tracking phase gimbal angle rate command ?cmd—Trk after the initial control period T.

Abstract: A system and associated method for compensating for thermal deformation of a spaced-based structure having a spacecraft payload. The system including a beacon source coupled to a first spacecraft for transmitting a first signal and a beacon sensor coupled to a second spacecraft for receiving the first signal and providing measurement data derived from the first signal. At least one attitude sensing device is coupled to the second spacecraft for determining estimated spacecraft attitude data for the second spacecraft. A processor on the second spacecraft is configured to process ephemeris data of the first and second spacecraft, beacon measurement data, estimated spacecraft attitude data, and gimbal angular position data to estimate spacecraft structural deformation.

Abstract: A laser metrology system for estimating the deformation of a structure is provided. The system includes a plurality of laser beam position detectors distributed across a surface of the structure. Each laser beam position detector is intersected by a laser beam and is configured to determine the change in location of the intersection point in at least one dimension. By determining the change in location of the intersection point for each laser beam position detector, the laser metrology system can calculate the deformation of the structure that caused these changes in location.

Abstract: A method and system for minimizing the solar array sun tracking disturbance is disclosed. The method separates the North solar array wing stepping and South solar array wing stepping in time, and use the disturbance caused by one solar array wing to cancel the disturbance caused by the other solar array wing. It separates the step times of these two solar arrays by a half cycle of the array frequency excited by the solar wing drive stepping. Because of the symmetry between the North and South solar arrays, their disturbances cancel each other out.

Abstract: Methods and structures are provided for reducing pointing errors &zgr; of satellite antennas and for generating broad field-of-view satellite attitude acquisition patterns. In one method embodiment, satellite transmit beams have estimated pointing attitudes &bgr; and are transmitted to overlap on a ground-based receiving terminal which has a known terminal location &lgr; and which measures received signal strengths &agr;. Pointing errors &zgr; of the transmit beams are then determined from the estimated pointing attitudes &bgr;, the terminal location &lgr; and the signal strengths &agr; and the pointing errors &zgr; are subsequently reduced by revising the pointing attitudes &bgr;. Other method embodiments utilize known signal-strength functions and antenna signals with known signal parameters such as frequencies and/or modulations.

Abstract: A method and apparatus for determining and correcting for phased array mispointing errors, particularly those due to structural deformation, is disclosed. The method comprises the steps of receiving a signal from each of a plurality of signal sources at at least one receiving sensor disposed away from the phased array in a direction at least partially toward a receiver of a transmitted signal from the phased array, and determining the phased array pointing from the received signals. The apparatus comprises a receiving sensor for receiving a signal from each of a plurality of signal sources, the receiving sensor disposed away from the phased array in a direction at least partially toward a receiver of a transmitted signal from the phased array, and an array pointing computer for determining the direction of the phased array from the received signals.

Abstract: A method and system for minimizing the solar array sun tracking disturbance is disclosed. The method separates the North solar array wing stepping and South solar array wing stepping in time, and use the disturbance caused by one solar array wing to cancel the disturbance caused by the other solar array wing. It separates the step times of these two solar arrays by a half cycle of the array frequency excited by the solar wing drive stepping. Because of the symmetry between the North and South solar arrays, their disturbances cancel each other out.

Abstract: Methods and structures are provided for reducing pointing errors &zgr; of satellite antennas and for generating broad field-of-view satellite attitude acquisition patterns. In one method embodiment, satellite transmit beams have estimated pointing attitudes &bgr; and are transmitted to overlap on a ground-based receiving terminal which has a known terminal location &lgr; and which measures received signal strengths &agr;. Pointing errors &zgr; of the transmit beams are then determined from the estimated pointing attitudes &bgr;, the terminal location &lgr; and the signal strengths &agr; and the pointing errors &zgr; are subsequently reduced by revising the pointing attitudes &bgr;. Other method embodiments utilize known signal-strength functions and antenna signals with known signal parameters such as frequencies and/or modulations.

Abstract: A method, apparatus, article of manufacture, and a memory structure for compensating for instrument induced spacecraft jitter is disclosed. The apparatus comprises a spacecraft control processor for producing an actuator command signal, a signal generator, for producing a cancellation signal having at least one harmonic having a frequency and an amplitude substantially equal to that of a disturbance harmonic interacting with a spacecraft structural resonance and a phase substantially out of phase with the disturbance harmonic interacting with the spacecraft structural resonance, and at least one spacecraft control actuator, communicatively coupled to the spacecraft control processor and the signal generator for inducing satellite motion according to the actuator command signal and the cancellation signal.

Abstract: A method, apparatus, article of manufacture for compensating for solar wing thermal shock in a spacecraft. The method comprises the steps of determining solar wing compensation to compensate for the thermal shock disturbance and rotating the solar wing about a second axis according to the determined compensation, wherein the second axis is substantially perpendicular to the first axis and to a vector from the spacecraft to the sun. The solar wing compensation can be based on predicted solar wing deflections due to thermal shock perturbations, or if available, solar wing temperature measurements. In an embodiment of the present invention applicable to satellites with multiple solar wings, asymmetric control is applied by independent adjustment of the thermal shock compensation loop controlling each solar wing. In yet another embodiment of the present invention, the solar wing position actuator is further commanded by a feedback control loop using the measured spacecraft attitude.