The military relies heavily on the Global Positioning System (GPS) for positioning, navigation, and timing (PNT), but GPS access is easily blocked by methods such as jamming. In addition, many environments in which the country’s military operates (inside buildings, in urban canyons, under dense foliage, underwater, and underground) have limited or no GPS access. To solve this challenge, Adaptable Navigation Systems (ANS) seeks to provide GPS-quality PNT to military users regardless of the operational environment.
ANS addresses three basic challenges through its Precision Inertial Navigation Systems (PINS) and All Source Positioning and Navigation (ASPN) efforts: 1) better inertial measurement units (IMUs) that require fewer external position fixes; 2) alternate sources to GPS for those external position fixes; and 3) new algorithms and architectures for rapidly reconfiguring a navigation system with new and non-traditional sensors for a particular mission.
Complementing DARPA's Micro-PNT program, which is developing chip-scale inertial sensors that are navigation grade or better, PINS is developing an IMU that uses cold atom interferometry for high-precision navigation without dependence on external fixes for long periods of time. Atom interferometry
involves measuring the relative acceleration and rotation of a cloud of atoms within a sensor case, with potentially far greater accuracy than today's state-of-the-art IMUs.
However, because even long-duration IMUs require an eventual position fix, the ASPN effort is developing sensors that use signals of opportunity that are non-navigation signals from sources like television, radio and cell towers, and satellites, as well as natural phenomena, such as lightning.
Integrating and tuning different sensors, maps and other components into a navigation system is expensive and slow, resulting in platform and mission-specific solutions. To address this integration challenge, the ASPN effort is also developing new fusion algorithms and plug-and-play processing architectures for rapid integration and near-real-time reconfiguration or upgrading of sensors, IMU devices, maps and databases on a navigation system. By allowing flexible combinations of existing and new navigation sensors, ASPN seeks improvements in accuracy, robustness and cost of navigation systems across a wide range of platforms, environments and missions.