The problem of real-time, on-board star pattern identification is considered which must precede any spacecraft attitude estimation algorithm based on measured line of sight directions to stars. Following the use of the search-less k-vector method[1, 2] to access feasible candidate stars, a tiered logical structure is introduced in which inter-star angles for pairs, triples and general elementar...

Star trackers provide spacecraft with the most precise estimate of their orientation,or attitude, with respect to a fixed celestial coordinate system. The star tracker camera views a patch of the celestial sphere and attempts to recognize the stars contained within. Then from the known star positions it will calculate the attitude. A number of pattern recognition methods, each with various stre...

We propose a spatio-temporal array-receiver (STAR) for asynchronous code division multiple access (CDMA), using a new space/time structural approach. First, STAR performs blind identification and equalization of the propagation channel from each mobile transmitter. Second, it provides fast and accurate estimates of the number, relative magnitude, and delay of the multipath components. From this...

A new star recognition method based on the Adaptive Ant Colony (AAC) algorithm has been developed to increase the star recognition speed and success rate for star sensors. This method draws circles, with the center of each one being a bright star point and the radius being a special angular distance, and uses the parallel processing ability of the AAC algorithm to calculate the angular distance...