摘要:
The method according to the invention allows to determine the yaw angle of a satellite from the reading of two different sensors measuring the roll and/or pitch angles, provided that the reference point of the two sensors are not identical. A description is given basically for geostationary satellites but the method can be applied directly to satellites which are stationary with respect to any star. The method can be employed for circular and non-circular orbits.
摘要:
A computing device may detect that a space object has undergone a maneuver and may attempt to calculate a solution to that maneuver based in part on start and stop times and thrust uncertainties associated with the detected maneuver. However, the computing device may sometimes be unable to calculate an acceptable solution for a detected maneuver given these initial start and stop times and thrust uncertainties. Thus, the various embodiments provide for a computing device and methods implemented by a processor executing on the device for identifying and calculating a recovery maneuver of a space object when an acceptable solution for a detected maneuver cannot be determined. In the various embodiments, a computing device processor may generate a recovery maneuver based on the detected maneuver, and the processor may adjust the start and stop times and the uncertainty values of the recovery maneuver until an acceptable solution is found.
摘要:
A trilateration positioning system comprising: a plurality of transmitters having known ephemerides that transmit dual frequency ephemeris and time data wherein at least one of said transmitters is beyond earth orbit; a plurality of transmitter clocks providing time data to each of said transmitters; a receiver that receives said dual frequency ephemeris and time data from four or more of said transmitters and uses trilateration to determine the location of said receiver; and a receiver clock providing time data to said receiver.
摘要:
This disclosure provides a vertical position and velocity determination system for inertial measurement unit (IMU) integrated with a barometric altimeter in the same device (IMU-baro). The system includes a rate of turn input connected to receive a measured IMU-baro rate of turn; an acceleration input connected to receive a measured IMU-baro acceleration; a barometric pressure input connected to receive a measured IMU-baro altitude; a first Kalman filter connected to the rate of turn input and to the acceleration input to estimate a roll and pitch of the IMU-baro based on the measured IMU-baro rate of turn and the measured IMU-baro acceleration; and a second Kalman filter connected to the acceleration input, to the barometric pressure input, and to the first Kalman filter
摘要:
A method and apparatus for autonomous navigation for deep space missions using the sun as the reference body and determining the spacecraft orbit based on observations made on the sun using onboard instruments. Two types of observation data, the direction of the spacecraft relative to the sun as a function of time and the optical Doppler shift due to the motion of the spacecraft relative to the sun, can be used for the spacecraft orbit determination. A dual imaging system which functions as a sun imager taking images of the sun against star backgrounds during the cruise phase and as a regular optical imager taking pictures of the targeting planetary body during the approaching phase is also described.
摘要:
A method and a device for determining the attitude of a spacecraft by attitude determination using fast star identification using a so-called star tracker is proposed with an improved algorithm with pattern extraction based on rings having an equal area. In some embodiments a confidence value is attributed to the candidates of the matching process improving significantly the verification process.
摘要:
The present disclosure provides a jump detection system for inertial measurement unit (IMU) integrated with a barometric altimeter in the same device (IMU-baro). The processor is configured to record time-series data of both a vertical component of the measured IMU-baro acceleration and the estimated vertical velocity of the IMU-baro, detect a potential jump by comparing the vertical component of the measured IMU-baro acceleration to one or more acceleration thresholds, and, validate the potential jump by comparing a difference between a maximum velocity and a minimum velocity within a vicinity of the potential jump in the time-series data of the estimated vertical velocity of the IMU-baro to a velocity threshold.