Patent ID: 9432637
Filing Date: 2016-08-30
CPC Classification: G06K,G06T,H04N

Claim Text:
1. A computer-based method for generating vehicle position fixes of a vehicle having a vehicle position, a vehicle heading, a vehicle attitude, a vehicle coordinate system, and a vehicle position uncertainty, comprising: (a) selecting a snippet pixel from each of a plurality of image snippets, the plurality of image snippets being associated with a target, the target having a target position, each of the snippet pixels being associated with an estimated target position, a snippet pixel time, and a target size of the target, each of the snippet pixels having a snippet pixel azimuth angle, a snippet pixel azimuth angle uncertainty, a snippet pixel declination angle, a snippet pixel declination angle uncertainty, a snippet pixel distance from the vehicle, and a snippet pixel distance uncertainty; (b) measuring the target size; (c) computing a pixel selection uncertainty for the snippet pixel based on the measured target size; (d) repeating steps (a)-(c) for each of the plurality of snippets; (e) computing a snippet pixel position in an earth coordinate system at the snippet pixel time for each of the snippet pixels based on the vehicle position in the earth coordinate system at the snippet pixel time, the vehicle heading in the earth coordinate system at the snippet pixel time, the vehicle attitude in the earth coordinate system at the snippet pixel time, the snippet pixel azimuth angle in the vehicle coordinate system at the snippet pixel time, the snippet pixel declination angle in the vehicle coordinate system at the snippet pixel time, and the snippet pixel distance from the vehicle at the snippet pixel time; (f) computing a snippet pixel position uncertainty for each of the snippet pixel positions based on the vehicle position uncertainty at the snippet pixel time, an estimate of the snippet pixel azimuth angle uncertainty, an estimate of the snippet pixel declination angle uncertainty, an estimate of the snippet pixel distance uncertainty, and the pixel selection uncertainty; (g) selecting a reference position and a reference time based on the snippet pixel position uncertainties and the snippet pixel times; (h) determining remaining snippet pixels based on the reference position, the remaining snippet pixels each having a remaining pixel's pixel selection uncertainty and a remaining pixel snippet pixel pointing uncertainty at the snippet pixel time; (i) computing a pixel offset based on the reference position and the remaining snippet pixels; (j) computing a remaining snippet pixel position uncertainty for each of the remaining snippet pixels based on the vehicle position uncertainty at the snippet pixel time of the reference position, the remaining pixel snippet pixel pointing uncertainty, and the remaining pixel selection uncertainty; and (k) creating the vehicle position fixes for the target based on the remaining snippet pixels, the reference position, the snippet pixel times, and the remaining snippet pixel position uncertainties.