by John Conrad (gCaptain) Loran-C was an incredibly reliable and accurate analog land navigation system operated by the US Coast Guard. Despite its impressive performance, it had some drawbacks, such as limited coverage, expensive infrastructure, and the need to maintain a large number of radio stations in remote areas. Now with concerns about GPS jamming and hacking, should we consider restoring the United States’ once robust system of Loran-C stations?
Before it was decommissioned in 2010, then-USCG Commander Tad Allen proposed upgrading the system to E-Loran, a digitized and automated version of Loran-C that would provide improved accuracy and resistance to jamming and other forms of interference. However, due to a lack of Pentagon concern regarding a potential technological or space war with China and vulnerabilities to Russian hackers at the time, Congress did not fund the proposal and the old Loran stations were decommissioned. To implement future upgrades, the entire network of Loran stations will have to be rebuilt.
Several countries, including the United Kingdom and Russia, continued to invest in the development of E-Loran systems. Despite the potential advantages of E-Loran, however, it has not been widely adopted and is not currently used as a backup to GPS.
The death blow for E-Loran came from a complete lack of interest from Silicon Valley, which in 2010—before the advent of crowd-sharing networks like Uber—preferred bits over atoms and mostly didn’t believe that small devices like cellphones – which operate on very short wavelength radio frequencies – could handle the long wavelength transmissions of a high frequency radio system like Loran.
Also read: eLORAN 101 – The return of LORAN C?
Today, however, high-frequency chips are ubiquitous—you can decode HF navtex and DSD signals with a $30 dongle from Amazon—and the benefits of E-Loran can be significant. What benefits? First is penetration. The phone now uses advanced signal processing and intelligence to augment GPS to provide a location when you enter a parking lot, a building, or even on a hike in dense foliage. This is necessary because GPS signals use short wavelengths that do not penetrate structures very well. Loran signals – with their long wavelengths that travel long distances – do.
Read also: LAURENT Overboard
What is better for Laurent?
Some of the advantages of Loran-C over GPS were:
- Better performance in high latitude regions: GPS signals can be significantly degraded in high latitude regions due to the geometry of satellite orbits. In contrast, Loran-C signals are not affected by satellite orbits and can provide accurate navigation information in high latitude regions. This has become increasingly important as Arctic security has become a top priority.
- Higher accuracy for short-range navigation: Loran-C was originally designed for short-range navigation and can provide higher accuracy than GPS for distances up to 1000 nautical miles.
- Greater resistance to jamming: GPS signals are vulnerable to intentional or unintentional interference, such as jamming or spoofing. Loran-C signals are less susceptible to jamming or tampering, making it more reliable in certain situations.
- Availability of back-up systems: Loran-C had back-up systems and could provide back-up navigational information in the event of GPS outage or failure.
- Being a ground-based system, it can be better protected and repaired during a conflict with a space-based adversary like Russia.
In the United States, the Department of Homeland Security (DHS) conducted a feasibility study of establishing an E-Loran system as a backup to GPS in 2008. The study concluded that E-Loran has significant potential as a backup system, but implementation of the system would require significant investment and support from the private sector. Despite promising survey results, the E-Loran system was not implemented as a backup to GPS in the United States due to budget constraints and lack of interest from the private sector.
Also read: eLoran sparks debate in Washington – does it really matter?
Can the Loran system be restored?
As space-savvy adversaries such as Russia and China become increasingly aggressive, the Defense Department has begun reinvesting in high-frequency communications systems. While the US Navy and US Coast Guard continue to have limited interest in terrestrial radio, the US Air Force is investing heavily in “legacy” radio systems. Just last year, the US Air Force, in partnership with BAE Systems, awarded a $176 million contract to ham radio maker FlexRadio to put HF radio back into the cockpits of its planes, and Ukraine uses ham radios to communicate behind enemy lines. Old is new again, but rebuilding the entire Loran system will require buying land, running millions of miles of cable, installing new radio infrastructure, and training personnel to operate and maintain the system. This cost will far exceed the several hundred million the USAF is investing in the HF.
The Loran system could be restored in densely populated areas with existing infrastructure for less, but coverage would be limited. So is there a better way?
Amateur radio FT8
FT8 is a digital communication mode used by radio amateurs to make radio contact over long distances. It was developed by Nobel Prize winning physicist Joe Taylor (K1JT) and radio amateur Steve Franke (K9AN) as part of the WSJT-X software package for amateur radio communications.
The FT8 is designed for weak signal communications and is particularly useful for making contacts in poor propagation conditions, such as during low solar activity or when atmospheric noise is high. The mode uses Internet Synchronized Clocks, a fixed length 15 second transmission, during which the transmission is spread over multiple subcarriers, providing a high degree of error correction.
The FT8 is characterized by its highly automated operation, where the operator simply selects a frequency, sets the transmit power and lets the software handle the rest. The software exchanges information between the two stations, and the operator receives confirmation of successful contact.
The FT8 has gained popularity among radio amateurs due to its ease of use, high degree of error correction, and ability to make contacts over long distances in poor propagation conditions. It is usually used for weak signal digital modes in the HF bands such as 6 meters, 2 meters and 70 centimeters. Today, thousands of stations transmit time-synchronized FT8 signals from fixed stations around the world that provide access to every corner of the planet.
Don’t build, Crowd Source
Building a new E-Loran system would probably be too expensive for even the best-funded defense organizations such as the Ministry of Defense or NATO, but with radio amateurs already broadcasting time-accurate HF signals synchronized from fixed transmission sites, it is now possible to triangulate a position. The problem is noisy. Are all these ham clocks perfectly synchronized? Is everyone streaming from their claimed locations? What if a HAM radio operator moves and doesn’t update his position with the FCC or operates the FT8 from a mobile trailer or boat?
This is where AI can help. It is possible for the AI to monitor for inaccuracies in the system. It can monitor stations over a long period of time and rate them according to their accuracy and signal strength. It can flag and remove false alarms. All of this, of course, requires a lot of processing power, but any iPhone was more powerful than any supercomputer when GPS was invented.
Programming would also be a challenge, but with a Nobel Laureate like Dr. Joe Taylor, smart radio amateurs, help from Apple and Google, and funding from the Ministry of Defense, it should be possible to use the system for navigational purposes and provide a back-up to GPS while allowing better location for our phones.
In conclusion, rebuilding the Loran-C system is a feasible endeavor, albeit one that will require significant investment, time and expertise. However, this is not an insurmountable task, given that the most popular and revolutionary vessel tracking technology today – web-based AIS systems such as Marine Traffic – is already in use by hobbyist reception radios around the world and has proven itself to be reliable and an invaluable asset to the shipping industry. A radio-based navigation system like E-Loran would require licensed and regulated radio transmitters, but fortunately thousands of these stations are already operating with FT8 on every continent, making mass demand for an HF navigation alternative to GPS possible, eliminating the need for the USCG to acquire land and to maintain stations.
At least theoretically.
Related Video – FT8 Review by HRCC
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