The existence of GPS jammers is a potential danger

A satellite company that provides ship monitoring and tracking services is studying whether it can use its new formation flying satellites to locate GPS jammers and potential interference.

Since the beginning of 2019, Virginia-based HawkEye 360 ​​has flown three microsatellites in the sun’s synchronous polar orbit. Hawk satellites can detect radio frequency transmissions on the earth’s surface and can independently determine the source as a coordinated star cluster s position. They are currently used to detect the transmission of automatic identification system (AIS) equipment that ships need to carry, and independently geotag the source so that the reported ship position and actual position can be compared and reported. The system can locate a transmitter with an accuracy of 500 meters based on the signal. This may improve as HawkEye establishes its constellation.

The company has committed to putting five more star clusters into space by the end of 2021, and HawkEye CEO John Serafini told Inside GNSS that there are plans to launch another star cluster. By mid-2022. Through the B round of financing completed earlier this year, financing for other satellites is in progress. With seven satellites in orbit, the return rate (that is, the frequency at which the satellites fly at the same location on the earth) will drop from approximately once every five hours to once every 30 minutes. Serafini said.

Each group of satellites fly in formation, and this capability is achieved through a specially designed propulsion system. Their software-defined radio can be tuned to frequencies in the range of 144 MHz to 15 GHz (approximately VHF to Ku band). To be detected from space, the signal strength on the ground must be 1 watt or higher.

Serafini said: "In general, if the power of a signal is greater than one watt between 150 Hz and 15 GHz, we can detect it, and the signal can be geo-tagged, processed, and analyzed." During the month, cluster 1 detected 11 million geographic locations regardless of various signals.

All these functions are provided in a beautiful small package. The first three satellites each weigh only 15 kilograms. Starting from cluster 2, each cluster will increase by 25 to 28 kg. The company's initial target market is services for defense, intelligence, and security applications. HawkEye is now evaluating the provision of a new service that will identify the location of gps jammer.

Serafini said: "GPS interference is part of our product roadmap," the company hopes to provide this service within about six months. "We must evaluate opportunities and develop products."

Logan Scott of LS Consulting, a navigation and telecommunications signal expert, said that it is perfectly reasonable that HawkEye satellites can locate GPS jammers. Scott said that he was introduced to the technology in a speech a few years ago, and although he has not yet conducted a link analysis, he believes the technology has this potential. . "If that's a big disruptor, yes, I can definitely see something like that-you can do some cool things.

Although indirectly, identity theft can also be better understood. Other organizations have used AIS data in this way. For example, if the AIS location data indicates that the ship is crossing land, it strongly indicates that the identity has been stolen.

Maybe Hawkeye can do similar things based on other modes of transportation such as trucks and trains. Serafini said that if publicly available location data is transmitted via trucks or other assets, satellites can receive these signals directly. The company can also use data from third-party providers. If the reported location does not match the actual location, it may be a fake result.

Serafini said: "We haven't done it yet, but we will, and we believe that depending on the assets we want to track, we can buy commercially available databases."

HawkEye can even map these disturbances over time. For the truck driver, when his GPS jamming personal privacy device interfered with the Ground Augmentation System (GBAS) at Newark Liberty International Airport in Newark, New Jersey, it might be helpful. past. The intermittent interference was a headache at the time.

The system may also be able to collect enough data to determine whether signals in frequency bands near the frequency bands used by GPS will interfere with GPS receivers. GPS users have recently faced this possibility from Ligado Networks’ proposal, which hopes to use satellite frequencies close to the frequencies GPS uses for ground services. Using the signal frequency, power and location data of the HawkEye system, it can be determined whether the Ligado signal is interfering with GPS equipment.

Scott said, however, one of the challenges of doing this is to find the specific transmitter that may be causing the problem-especially if that transmitter is part of a network with other nearby transmitters. The fact that the communications transmitter directs most of its power to the ground makes the situation even more complicated.

"I'm not saying it's impossible," Scott said. "I don't want to compromise the capabilities of these people; this is a very capable group. But at the same time, I have to be careful when evaluating."

HawkEye is still analyzing it, and it is too early to further understand the potential of this capability.

Scott suggested that HawkEye might be able to create a heat map to show the signal and its strength in various geographic locations. "The heat map will indicate whether you can see any problems in that area."