1. An apparatus to track a mobile subject based on Global Navigation Satellite Systems (GNSS) data, comprising: a motion detector to detect motion of the mobile subject independently of the GNSS data; an actionable position and speed determination unit configured to receive the GNSS data and determine an actionable position and an actionable speed of the mobile subject, wherein a current actionable position is a sum of a prior actionable position and a product of a degraded position difference and a position tracking coefficient, the degraded position difference being a product of a position degrade coefficient and a difference between a current GNSS position and the prior actionable position, the position degrade coefficient being a function of most recent and prior GNSS position solution metrics and GNSS signal metrics, and the position tracking coefficient being a function of the actionable speed and a detected motion from the motion detector, and wherein a current actionable speed is a function of a prior actionable speed and a degraded speed estimate, the degraded speed estimate being a product of a speed estimate and a speed degrade coefficient, the speed estimate being a function of the prior speed estimate and a GNSS speed estimate, the speed degrade coefficient being a function of most recent and prior GNSS speed solution metrics, and the speed degrade coefficient being a function of the GNSS signal metrics; and a boundary test unit configured to evaluate a boundary violation according to the current actionable position and current actionable speed of the mobile subject relative to a predetermined boundary.