A satellite company that currently provides ship monitoring and tracking is studying whether it can use its new formation flying satellites to locate GPS interference sources and possible interference. Since the beginning of 2019, in HawkEye 360 in Virginia, three microsatellites have been flying in a sun-synchronous polar orbit. The Hawk satellite can capture radio frequency transmissions from the earth’s surface and independently determine the location of the source as a coordinated cluster. They are currently used to detect the transmission of automatic identification system (AIS) equipment for transporting ships, and must independently locate the source so that the reported ship position and actual position can be compared and reported. According to the signal, the system can locate the transmitter with an accuracy of 500 meters. If HawkEye expands its constellation, this may improve.
The company has promised to launch five more clusters into space by the end of 2021, and John Serafini, CEO of HawkEye, told Inside GNSS that it plans to launch another cluster in mid-2022. As a result of the Series B financing completed earlier this year, additional satellites will receive funding. Serafini said that with seven satellite clusters in orbit, the return rate (the frequency at which satellites fly at the same point on the earth) will increase from about every five hours to about once every 30 minutes.
Each constellation of satellites is flying in formation. This capability is achieved through a specially developed propulsion system. Your software-defined radio can set the frequency from 144 MHz to 15 GHz (approximately FM to Ku band). In order to be recognized from space, the signal power on the ground must be 1 watt or higher.
Serafini said: “If the power of a signal is higher than one watt between 150 Hz and 15 GHz, we can usually identify the signal and geolocate, process, and analyze it.” In the first 14 operations In the middle of the month, cluster 1 identified the independent geographic locations of 11 million signals. All these functions are provided in a fairly small package. The first three satellites weigh only 15 kg. Starting from cluster 2, each cluster jumps to 25 to 28 kg.
The company’s initial target market is defense, intelligence and security application services. Now, HawkEye is studying the provision of a new service through which the location of the gps jammer can be determined. Serafini said: “GPS interference is on our product line.” The company hopes to provide the service in about six months. “We must evaluate opportunities and develop products.”
Logan Scott of LS Consulting, an expert in navigation and telecommunications signals, said that it is reasonable for HawkEye satellites to locate GPS jammers. Scott said he was introduced to the technology in a speech a few years ago. Although he did not do any link analysis, he believes that this technology has potential. “If this is a huge disturbance. Yes, I will definitely see something similar-you can do some good things.” Although it is indirect, it is also possible to learn more about deception. Other organizations have used AIS data in this way. For example, if the AIS location data indicates that the ship is crossing dry land, it strongly indicates that there is deception.
Hawkeye may be able to do similar things based on other modes of transportation such as trucks and trains. Serafini said that when transmitting public location data from trucks or other assets, satellites can directly receive these signals. Alternatively, companies can use data from third parties. If the reported location does not match the actual location, it may be due to spoofing. Serafini said: “We haven’t done this yet, but we will do it, and we believe that based on the assets being tracked, we can buy some commercially available databases.”
HawkEye can even map such failures over time. This may be useful if the truck driver’s GPS jamming data protection equipment interferes with the ground augmentation system (GBAS) at Newark Liberty International Airport in Newark, New Jersey. The temporary riot at the time was a mystery. The system is also able to collect enough data to determine whether signals in the frequency band around the frequency band used by GPS will interfere with the GPS receiver. GPS users have recently discovered this possibility due to a proposal by Ligado Networks, which hopes to use satellite frequencies adjacent to GPS frequencies for ground services. The signal frequency, power and location data of the HawkEye system can be used to determine whether the Ligado signal interferes with GPS equipment.
According to Scott, one of the challenges will be to identify a particular site that may cause problems, especially if the site is part of a network with other sites nearby. The fact that communication channels concentrate most of their performance on the floor complicates the situation. Scott said: “I don’t want to say impossible.” “I don’t want to shorten the capabilities of these people. They are a very capable team. At the same time, I try to evaluate carefully.” HawkEye is still conducting his analysis. It is too early to understand the potential of this skill.
Scott suggested that HawkEye can create a heat map to show the signal and its performance in different geographic locations. “The heat map shows whether there may be a problem in the area.” Serafini said they already have such a service. “One of the products we offer today is RFMosaic, which can check a specific geographic location as well as a specific time and frequency range, and map the signal of interest we see-the spectral energy of the area.” According to the company’s website, RFMosaic includes functions to identify RF activity over time and identify potential sources of interference.