Target Oriented Tracking System (TOTS)
TOTS is a generic, real-time, low-latency, multi-target sensor data fusion and tracking system designed to track air-breathing, ballistic missile and maritime surface targets.
The principles upon which TOTS is based have been developed from initial concepts arising out of the concurrent scalable computing field that was under intense development in the mid-1980s. During this time L3 ASA was very active in this area. These scalable processing concepts were viewed as being particularly appropriate to countering the massive ballistic missile threats of the “cold war”, but remain equally applicable to today’s threats.
TOTS’s low-latency architecture and Autonomous Multiple Model (AMM) construct ensures that target tracks are formed as quickly as possible after entering sensor coverage or separating from a parent object.
The TOTS Approach
The TOTS system provides robust, high-precision, low-latency target tracking using data either from a single 3-D sensor, or from multiple, disparate sources, which can include both active and passive sensor types. It can also incorporate track data from platforms unable to supply unfiltered plots.
TOTS is based on an unscented Kalman filter paradigm to provide track filtering closely matched to target behaviour over a wide range of kinematic envelopes. In this concept, each track comprises a number of track models, each representing a specific subset of the target’s kinematic envelope, and decides which of these best represents the targets current behaviour. In this way, very accurate tracking can be maintained during periods of steady behaviour while allowing tracks to be maintained continuously through periods of more changeable dynamics.
TOTS is equipped with models covering all phases of a ballistic missile’s trajectory and the full extent of an airborne and surface target’s kinematic envelope. The models are individually enabled for any given system and environment — allowing the optimum set for any specific system to be active while the non-relevant ones are disabled to prevent them corrupting the tracking or consuming unnecessary computing resources. Each model is parametrically configurable to allow optimisation for any given target set. As a result, TOTS can be used in a wide variety of applications with many target types — ranging from maritime targets, aircraft (fixed and rotary wing types), cruise missiles, ballistic missiles, or space objects — even simultaneously. Should the need arise to deal with new target types, new models, designed to match their specific behaviour, may readily be incorporated into TOTS.
TOTS’s AMM construct is maintained within a multiple hypothesis tracking (MHT) architecture to ensure that tracks are formed as quickly as possible after entering sensor coverage or after separating from a parent object. Rigorous pruning of less-likely hypotheses keeps the computing requirements within bounds even for dense target environments. This combined AMM/MHT approach supports not only data fusion tracking from more than one sensor of similar capabilities, also provides robust tracking between sensors of differing capabilities.