Abstract: The present inventions comprise a A method of estimating a minimum range for a target with respect to a first point of interest, independent of actual, range to the target, comprising obtaining three bearing data points; using the three bearing data points to determine a speed contribution Vos cos (??) of a first point of interest to a distance from a relative velocity vector over a time frame comprising t0 to t0?; determining an angle ?? as defined by the bearing relative to ownship's heading at the point in time of closest approach to a second point of interest; and calculating a minimum range using a predetermined formula.