Abstract: The invention is a method for radar registration by determining initially unknown azimuth and range biases (errors) in a system of multiple, overlapping coverage radars. Track data from multiple radar systems corresponding to a common target are associated into track pairs. Track pair data is then used to calculate state vectors in a multi-dimensional vector space (preferably six-dimensional), with state vector components corresponding to both position and velocity information. From these state vectors an average normalized statistical distance is calculated, where the averaging is over multiple track pairs. An azimuthal bias parameter (and preferably also a range bias parameter) are then varied to minimize the average normalized statistical distance, thereby finding the best estimates of the corrections required to register the multiple radars.

Abstract: A low cost easily deployed, yet highly accurate weapon mounted trajectory analysis radar system uses optimized Doppler radar signals to detect the actual trajectory of a projectile fired from an artillery piece such as a 155 mm Howitzer. The actual trajectory data is used to determine an atmospheric model that may be used to aim the weapon for future firings. The system includes a Doppler radar system having a turret mounted antenna that tracks the projectile, a digital signal processor using a FFT to convert radar pulses to trajectory data and a data processing system that analyzes the trajectory data to develop a true atmospheric model.

Abstract: A muzzle velocity chronograph method and apparatus for providing an accurate and precise measurement of the muzzle velocity of a projectile ejected from a gun.A conventional radar Doppler signal is sampled and digitized and arranged in a succession of groups, each group representing a separate time period. A fast-Fourier transform is then computed for each group of samples, and peak frequency measurements in the transformed data are tracked from one time period to the next. These peaks indicate the velocities of the projectile of interest and any other nearby moving objects. Finally, a least mean square error curve fit and standard regression algorithm are used to deduce the projectile's initial, muzzle velocity. The invention provides accurate muzzle velocity determinations even in circumstances where the Doppler signal contains substantial interference caused, for example, by random noise and the presence of moving fragments in the direction of the projectile.