Alternative Navigation Systems where GPS is Unavailable

Alternative Navigation Systems where GPS is Unavailable

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The US Army is turning to tiny cameras to help troops pinpoint positions in places where GPS navigation is unavailable.   

Although GPS has become a near-indispensable navigation aid for troops, the technology is not without its faults. GPS’s biggest drawback is that its signals can be easily blocked by local terrain features, such as mountains and tall buildings. The technology is also vulnerable to jamming and other forms of signal interference. Whatever the cause, when GPS fails warfighters are left to estimate their position by using traditional–and far less precise–methods, including maps and compasses.  

The Army Materiel Command’s Communications-Electronics Research, Development and Engineering Center (CERDEC) is looking to miniature cameras to provide vision-aided navigation support in satellite-denied situations. Vision Aided Navigation (VAN) for Army Applications is an applied research project aimed at characterizing the performance of vision-aided navigation systems and components as an alternate navigation solution for GPS denied or degraded Army combat environments. The project, which got underway in its current form in FY12 is estimated to mature to the point of technology transition by approximately FY22.

VAN uses a camera featuring a rapid frame rate to snap pictures of nearby objects. The system also incorporates inertial measurement units (IMUs)– accelerometers, gyroscopes and various other types of sensors. Working along with the camera, the IMUs generate continuous motion and direction data.  

The project  will likely first be deployed as a vehicle-mounted technology.

According to c4isr.net, CERDEC has already tested this approach by installing the system in a standard vehicle and driving along a major highway. In trials, the camera’s feature detection capability accurately captured everything in its path at both high and low speeds, including signage, other vehicles and trees.

There’s also the potential VAN could eventually be integrated with aerial vehicles.

Early test results have been encouraging. During recent tests in urban settings, a soldier-mounted prototype enabled the operator to stay on nearly the exact trajectory to the path generated by GPS and other sources. The positioning performance obtained from prototype systems showed very good performance, similar to that which can be obtained from GPS position estimates.

A dual-camera version of VAN, capable of stereo imaging, could become a viable option at some future point as long as size, weight, power and cost requirements can be met. Such a system would provide 3-D-level imaging, with objects appearing to shift between camera views, providing depth/distance information the current single camera system lacks.

VAN is still in the early development phase and only a limited number of advanced laboratory prototype systems have been built.Laboratory studies and field trials are currently in progress and expected to continue for the next several years.