DARPA H6 Program To Develop Microsecond Precision Clocks For Use In Specific Climates

The DARPA Microsystems Technology Office recently issued a broad agency announcement for the H6 program which will seek to develop ultra-small, low power clocks that can maintain microsecond precision for at least one week in temperatures from -40 to 85 degrees Celsius. These clocks will be used to aid military forces in maintaining precise positioning, navigation, and timing (PNT) in case of GPS navigation failure due to satellites being damaged, destroyed, or jammed.

Ubiquitous compact timing is critical for navigation, and also for communications, electronic warfare (EW), and intelligence, surveillance, and reconnaissance (ISR). The use of H6 level clocks would remove PNT timing from dependence on navigational satellites, and enable signal assurance, pervasive communications security, and high-bandwidth communications. Currently, clocks do exist which can achieve the necessary performance, but their size, weight, and power consumption (SWaP) limitations preclude their use in a tactical setting.

H6 will be SWaP-constrained clocks that rely on compound mechanical clock technologies; sub-terahertz molecular clock technologies; or potentially an entirely new technology. The H6 project will be a five-year program with three phases:

  1. focusing on clock dependence on temperature and SWaP reduction;
  2. focusing on clock aging throughout the tactical temperature environment; and
  3. demonstrating an integrated tactical-grade clock and building five clocks.

Interestingly, the program is named H6 in a nod to an 18th century British ocean-navigation project that in five stages developed precise chronometers that helped British ocean navigators determine their vessels’ positions in longitude. British inventor John Harrison developed five generations of clocks, which he called H1 through H5. As Darpa points out, the longitude problem was the preeminent PNT challenge of the last millennium, while GPS denial is the greatest problem navigators face today.