초록 ▼

Sensors determine the kinematic measurements of a boosting missile, and the information is applied to a plurality of pairs or sets of filters, one of which is matched to the characteristics of a particular target type, and the other of which is general, and not matched to a particular target, for pr

Sensors determine the kinematic measurements of a boosting missile, and the information is applied to a plurality of pairs or sets of filters, one of which is matched to the characteristics of a particular target type, and the other of which is general, and not matched to a particular target, for producing from each filter of the set missile position, velocity, acceleration, and specific mass flow rate states, and covariances of those states. From the filtered information, the estimates are made of at least missile mass flow rate, thrust, velocity at stage burnout, and remaining burn time. The likelihood is computed that the states and covariances from the filter sets represent the same target. The largest likelihood is selected as representing the target. In one mode, the estimated parameters are weighted and summed for a composite likelihood.

대표청구항 ▼

What is claimed is: 1. A method for tracking a target, said method comprising the steps of: sensing information about the target, which information comprises at least one of (a) position over time and (b) positional angle as a function of time relative to the sensor, coupled with sensor position; a

What is claimed is: 1. A method for tracking a target, said method comprising the steps of: sensing information about the target, which information comprises at least one of (a) position over time and (b) positional angle as a function of time relative to the sensor, coupled with sensor position; applying said information to a plurality of filter sets, each filter set including a special filter matched to the parameters of a one predetermined possible type of target and a general filter which is of a more general type, in that the general filter does not include specifics of the predetermined possible type of target, for producing, from each of the special and general filters, target position, velocity, acceleration, and specific mass flow rate states, and covariances of those states; calculating from the states and covariances of each of said set of filters at least (a) estimated actual mass flow rate, (b) estimated thrust, (c) estimated velocity at staging burnout, and (d) estimate of remaining burn time for that stage; computing the likelihood that the states and covariances produced by said special and general filters of each of said set of filters represent the same target; selecting as representing the target, from among said plurality of likelihoods, that one which has the greatest magnitude. 2. A method according to claim 1, wherein said step of calculating from the states includes the step of calculating (e) estimated specific impulse, (f) estimated mass at burnout of the current stage, and (g) estimated initial mass of the current stage. 3. A method according to claim 1, wherein said step of computing the likelihood in each of said set of filters includes the steps of: multiplying each of said mass flow rate, thrust, and states (position, velocity, acceleration, and specific mass flow rate) by at least one weighting factor to produce weighted parameters; and adding together said weighted parameters to produce a composite likelihood. 4. A method according to claim 1, further comprising the step of removing sensor biases by removing the measurement angular biases description="In-line Formulae" end="lead"θ(t)=(δθ o1T . . . δθ oNT δθr1T . . . δθrMT)description="In-line Formulae" end="tail" from the measurements of the reporting sensors. 5. A method for tracking a target, said method comprising the steps of: sensing information about the target, which information comprises at least one of (a) position over time and (b) positional angle as a function of time relative to the sensor, coupled with sensor position; applying said information to a plurality of filter sets, each filter set including a special filter matched to the parameters of a one predetermined possible type of target and a general filter which is of a more general type, in that the general filter makes no assumptions about the target, for producing, from each of the special and general filters, position, velocity, acceleration, and specific mass flow rate states, and covariances of those states; calculating from the states and covariances of each of said set of filters at least (a) estimated actual mass flow rate, (b) estimated thrust, (c) estimated velocity at staging burnout of the current stage, and (d) estimate of remaining burn time for the current stage; computing the likelihood that the states and covariances produced by said special and general filters of each of said set of filters represent the same target; and selecting from among said plurality of likelihoods, as representing the target, that one of said likelihoods which has the greatest magnitude. 6. A method according to claim 5, wherein said step of calculating from the states includes the step of calculating (e) estimated specific impulse, (f) estimated mass at burnout of the current stage, and (g) estimated initial mass of the current stage.