An orbiting detector of infrared energy may be used to detect the rock
et plumes generated by ballistic missiles during the powered segment o
f their trajectory, By measuring the angular directions of arrival of
the detections over several observations, the trajectory properties, l
aunch location, and impact area may be estimated using a nonlinear lea
st squares iteration procedure. Observations from two or more sensors
may be combined to form stereoscopic lines of sight, increasing the ac
curacy of the algorithm, A computer model is presented of an estimatio
n algorithm that determines what parameter, or combination of paramete
rs, will have a significant effect on the error of the tactical parame
ter estimation. This model generates observation data and then, using
the data, produces an estimate of the tactical parameters, i.e., the t
ime, position, and heading at launch and burnout, and an impact time a
nd position. For the expected range of values of each of the error sou
rces, the line-of-sight errors, a combination of focal-plane and attit
ude errors, had the greatest effect on the estimation of the launch an
d impact points.