Theme of the Week
PNT? It should be TNP We use the acronym PNT because position, navigation, and timing are inextricably connected. Of these, position is the easiest, as you can simply reference local landmarks. If that isn't an option, you can use the local time and the angle of the stars and sun in the sky (and a bit of skill) to locate your position. Conversely, once you establish your position, you can use these celestial coordinates to accurately deduce local time. This was the function of early observatories like the Royal Observatory Greenwich (ROG). Early mariners knew that you need time for navigating the open seas, which led to the world’s first synchronization network, and the rise of the first global empire (see below). Today, GPS is the world's primary source of PNT. While most people associate GPS with the P and N, in reality, its single biggest value is the T. Your location app may be free (though, is it really?), but the GPS time reference is critical for networks, financial transactions, and power grids and the source of a multi-billion dollar enterprise timing industry.
That being said, there is still value for position and navigation in areas that GPS cannot reach:
Self-driving vehicles, delivery drones, and flying taxis in urban canyons that block GPS signals. There are efforts to solve this “last 500 foot problem” using terrestrial beacons that are accurately (and securely) synchronized.
Underseas navigation, as the search for the lost submersible Titan has shown. Naval centers have traditionally driven the development of accurate clocks, inertial reference units, and quantum sensors that can accurately sense the Earth’s magnetic and gravity fields.
Last Week's Theme: Time is Money
As authorities scramble to locate the lost submersible Titan, the general public is finding out what navies have long known: you can't navigate underwater with GPS. This has spurred the development of stable clocks and inertial measurement units, as well as quantum sensors that can deduce position from variations in the Earth's gravity or magnetic field. Another option: a new paper that suggests we could use cosmic rays, or muons, that “pass through buildings, rocks, or water” for navigating underwater, underground, and indoors.
The head of space policy at the UK Ministry of Defense talked about the importance of space: “In Ukraine, we saw how denied airspace led to the necessity of space-based intelligence,surveillance and reconnaissance for informing decision-makers on the ground and identifying Russian disinformation,” but warned that “states are developing counter-space capabilities that threaten current and future satellites.”
Meanwhile, the UK Space Command chief innovation officer talked about the need to adapt to faster innovation from commercial space: “As technologies such as Lunar GPS start to become realities in the near future, standards are going to have to be set that are definitionally international.”
Another “open, collaborative, adaptable, and scalable” Quantum Communications Testbed was recently announced in Montreal “to provide companies, research organizations, institutions and small enterprises with an industrialized environment to experiment quantum networking technologies and as well to accelerate adoption strategies for use and application cases.”
While funding for startups in 2022 “was down 31% from 2021,” the “amount of money VC firms raised themselves hit $170.8 billion in 2022, according to PitchBook data, up from $158.5 billion in 2021.”
Quantum 2.0 Conference, June 18 - 22, Denver, CO
Q4I, June 27 – 29, Rome, New York
World of Quantum 2023, June 27 - 30, Munich, Germany
Small Satellite, August 5 – 10, Logan, Utah
Euroconsult, September 11 – 15, Paris, France
APSCC, October 10 – 12, KL, Malaysia
ITSF, Oct 30 – Nov 2, Antwerp, Belgium
UK National Quantum Technologies Showcase 2023, Nov 2, London, UK
SLUSH, Nov 30 – Dec 1, Helsinki, Finland
The More You Know...
“Whosoever commands the sea commands the trade; whosoever commands the trade of the world commands the riches of the world, and consequently the world itself," claimed Sir Walter Raleigh in the early 17th century. Portugal, Spain, France and Netherlands spent the 15th and 16th centuries carving up their part of the spice trade and the new world. Even though the British Empire held dominion over a quarter of the world by the 20th century, at that point they were well behind their rivals. So they passed the Longitude Act in 1714 with the understanding that maritime navigation relies on time. The first step: setting a time standard. Time can be deduced from the position of the stars and sun, but that requires a known location and precise observation equipment. Hence, the ROG was commissioned in 1675, setting the Greenwich Mean Time standard that we still use today. The next step: you need a stable and accurate timepiece. That was solved by John Harrison with the marine chronometer in the early 1700s.
The final step: you need a way to synchronize the two. So observatories were built at ports around the world to provide a time reference for passing ships using a time ball or other visual synchronization methods. By 1908, the British Navy operated 200 of these time signals in "coastlines or ports around the world." But this ambitious synchronization network didn't stop there. By the early 1800s, watchmakers, train stations, financial markets, and merchants started to require synchronization. At first, they would visit the ROG to set their timepieces. But this became an annoyance for the ROG, so a synchronization service was set up in 1840. For a fee, John Belville, then his wife Maria and daughter Ruth, would make the trip from Greenwich to their shop with a freshly synchronized watch. This manual synchronization process was replaced with telegraph lines by the mid-1800s, then radio synchronization in the 1920s, then, of course, GPS in the late 20th century.