Modern warfare has seen its share of technological improvements which have led to weapons that can be targeted with ever increasing levels of speed and accuracy, enabling weapon operators to react more quickly when a situation suddenly changes. While tanks, jets, missiles, combat planning systems, and other technological implements have kept pace with modern electronics, some familiar tools of modern warfare have remained virtually unchanged for centuries. Perhaps foremost among these essential components is the infantryman: the soldier carrying light arms deployed on foot.
Infantrymen have benefited to some extent from modern technology with the advent of laser sights, night vision goggles, and so forth. These have allowed the foot soldier to navigate at night, and accurately dispatch their targets. These technologies ultimately help to keep the soldier safe under the cover of darkness, help give the element of surprise when needed, and also help ensure that the first shot fired is the one that hits the mark.
In spite of these advances, one problem which persists is the cumbersome process of acquiring and striking a target. At night, modern night vision goggles passively amplify miniscule amounts of ambient light, such as starlight, and enable a soldier to see obscured targets in the dark. Once a target is found in this fashion, however, a soldier must flip the goggles out of the way and reacquire the target with the sight on his weapon. This takes time away from the soldier, during which he might be seen by the target itself, or the target might move. In addition, reacquisition with the weapon's narrower field of vision may be virtually impossible with a distant or moving target.
Alternatively, a soldier, upon viewing a target with night vision goggles, may engage a laser illuminator on his weapon. The illuminator projects a beam of laser light following the line of sight of the weapon and striking where the bullet will strike. The soldier can keep his goggles on and see the illuminated point. He can move the point of the illuminator until it points to his target, and then fire as needed. While somewhat faster than lifting the goggles and reacquiring the target through the weapon sight, the illuminator may have the unintended effect of giving away the soldier's position. The laser illuminator may be just as obvious to an enemy as it is to the soldier. In the time it takes to maneuver his weapon into position, he may already be spotted and in the weapon sight of his enemy.
In the hopes of solving this and other problems inherent with current infantry technology, U.S. military planners have envisioned a technological revolution for the foot soldiers of tomorrow, dubbed Future Force Warrior. The project envisions, among other improvements, the porting of an infantryman's weapon sight into a heads up display (HUD) built into his night vision goggles. Such goggles exist now, as in Sensor Technology Systems' Model 2733 Low Profile Night Vision Goggle. They have the ability to port a video feed into a beam combiner, overlaying a video image from a video source mounted in the weapon sight onto the center of the visual field of the goggles.
An example of such a combined image appears as prior art FIG. 1. Here, the video feed 102 from a weapon's sight is superimposed directly into the center of the night vision goggle's visual field 101. This is accomplished using a beam combiner, which optically overlays one image over another. Both images depict the same subjects, a group of soldiers accompanying an armored personnel carrier (APC). However, the video feed 102 remains stationary in the center of the visual field 101, obscuring content in the center of the visual field, in this case the APC and a soldier. The two images are distinctly offset, with the two soldiers to the right of the APC being repeated in both images. This offset, with two distinct images of the same target appearing in different places in the field of view, could confuse the soldier, causing a delay in engagement or a miss. If the soldier moves his weapon and turns his head simultaneously, the set of images moving in different directions may be even more confusing and disorienting to the soldier, potentially decreasing the soldier's ability to react and the accuracy of any shot fired.
Thus, it would be an advancement in the art if a video image from a video source could be integrated into the visual field of a heads up display without confusing or disorienting the observer, and without needlessly obscuring relevant visual content.