Defense Advanced Research Projects AgencyTagged Content List

Position, Navigation and Timing

Technologies relating to precision geolocation, time-keeping and synchronization

Showing 45 results for PNT RSS
Early GPS receivers were bulky, heavy devices. In 1983, DARPA set out to miniaturize them, leading to a much broader adoption of GPS capability.

In response to a call by Congress to establish a program to develop and efficiently transfer new hull, mechanical, and electrical technologies outside of normal U.S. Navy research and development channels, DARPA answered with the Advanced Submarine Technology (SUBTECH) program. Among ten technology demonstrations that successfully transitioned from the program to the Navy between 1989 and 1994 was the Non-Penetrating Periscope (NPP).

The NPP transformed submarine mast development when a prototype system using commercial visible and infrared spectrum cameras was built and demonstrated on the submarine USS Memphis in 1992. Using fiber optic data transmission, the new telescoping mast eliminated the need for the deep, hull-penetrating well that had been required to accommodate the optics tube on the then-current generation of submarines. The NPP also allowed greater flexibility in hull and interior design for future submarines.


ARPA launched the first satellite in what would become the world's first global satellite navigation system. Known as Transit, the system provided accurate, all-weather navigation to both military and commercial vessels, including most importantly the U.S. Navy’s ballistic missile submarine force.

Transit, whose concept and technology were developed by Johns Hopkins University Applied Physics Laboratory, established the basis for wide acceptance of satellite navigation systems. The system's surveying capabilities—generally accurate to tens of meters—contributed to improving the accuracy of maps of the Earth's land areas by nearly two orders of magnitude.

ARPA funded the Transit program in 1958, launched its first satellite in 1960, and transitioned the technology to the Navy in the mid-1960s. By 1968, a fully operational constellation of 36 satellites was in place. Transit operated for 28 years until 1996, when the Defense Department replaced it with the current Global Positioning System (GPS).

The U.S. Military relies on the space-based Global Positioning System (GPS) to aid air, land and sea navigation. Like the GPS units in many automobiles today, a simple receiver and some processing power is all that is needed for accurate navigation. But, what if the GPS satellites suddenly became unavailable due to malfunction, enemy action or simple interference, such as driving into a tunnel? Unavailability of GPS would be inconvenient for drivers on the road, but could be disastrous for military missions. DARPA is working to protect against such a scenario, and an emerging solution is much smaller than the navigation instruments in today’s defense systems.
In science, many of the most interesting events occur at a scale far smaller than the unaided human eye can see. Medical researchers might realize a range of breakthroughs if they could look deep inside living biological cells, but existing methods for imaging either lack the desired sensitivity and resolution or require conditions that lead to cell death, such as cryogenic temperatures. Recently, however, a team of Harvard University-led researchers working on DARPA’s Quantum-Assisted Sensing and Readout (QuASAR) program demonstrated imaging of magnetic structures inside of living cells.