Day: December 27, 2023

A screenshot from open-source satellite navigation interference tracking website, GPSjam.org from … [+] October 29 shows extensive navigational signal jamming in and around Israel but the area around Gaza near the Egypt border shows no activity.

GPSJam.org

While a number of reports describe Israeli jamming of GPS signals to thwart Hamas drones, there have been suggestions that Hamas itself is jamming satnav signals.

According to a recent article in the Israeli press, the country has stepped up efforts to jam or spoof GPS/GNSS signals to disrupt potential drone and missile attacks in northern Israel from Lebanon-based Hezbollah. It has also interfered with satellite navigation in and around Gaza.

The Israel Defense Force (IDF) said in a statement to Haaretz that it is disrupting satellite navigation systems “in a proactive manner for various operational needs… Citizens should be aware that the disruption can cause various and temporary effects on location-based applications.”

Observations by Israelis in northern Israel along the frontier with Lebanon appear to confirm the jamming with users noting occasional loss of GPS signals. GPS-enabled interactive navigation apps (Waze, Google, Apple) are apparently not showing traffic data or reports even when the GPS is working.

Real-time traffic data may have been purposely disabled to prevent Hezbollah or others from spotting patterns which may indicate the location of roadblocks or the movements of IDF formations in the area.

However, these observations relate to northern Israel as do most reports on jamming in the region. The latest public snapshot of jamming-spoofing activity from open-source GNSS (global navigation satellite system) interference tracking website GPSJAM shows significant jamming activity around Israel and the eastern Mediterranean region.

But it does not indicate jamming-spoofing activity in the lower lefthand corner of the Israel map overlay above where Gaza sits near the Egyptian border. That may be because there is not active jamming by Hamas or that such jamming is so localized that the tracking sensors that sites like GPSJAM aggregate data from cannot pick it up.

There is a thriving global market for consumer GPS-jamming devices. A quick browse online yields numerous choices for users seeking to evade GPS tracking with low-power devices that disrupt commercial GPS signals. One example is the APJ-16, a $1,200 all-in-one portable jammer.

The APJ-16 is advertised as an all-in-one portable GPS jammer capable of blocking signals on 16 … [+] frequencies at a range of 30 meters.

Jammer-store.com

According to the ad for the device, the APJ-16 can block GPS signals at 16 different frequencies in the 164-5900 MHz band. Users can “can select the frequencies you want to mute to leave others free,” a feature which might be useful for Hamas. The small four-pound (1.8 kg) device has a range of 30 meters (100 ft.) and a battery life of three hours.

Such power and range would theoretically be useful in throwing off the aerial or terrestrial drones which Israeli forces are now operating in Gaza. A 2020 feature in online blog Hackaday on commercially available mini GPS jammers illustrated their function and effectiveness.

Noting that the bulk of the GPS constellation is located at a significant distance (an altitude of 12,500 miles) from the earth’s surface and that antennas on most GPS-equipped devices – phones and to a lesser extent, drones – are quite small, the author pointed out that the signals they receive are weak.

“It doesn’t take much to overpower the legitimate signal,” Hackaday observed. “Keep in mind that a device like this isn’t trying to mimic a GPS satellite, it’s simply broadcasting out enough loud nonsense that the real satellite can no longer be heard.”

While the military grade drones the IDF is using have larger antennas and may enjoy greater signal strength, jammers like the APJ-16 go beyond simple mini car-tracker jammers.

One Israeli drone-maker currently claims that its platforms and operating system are the only drones not affected by Hamas’s GPS blocking efforts. I queried the company regarding this claim but received no response by publication time.

Information on how to build GPS jammers with commercial electronic components has been available for years and Hamas, Hezbollah and many other non-state actors have surely studied it. So have states like Iran which could possibly have provided Hamas and other terror groups with its own jamming equipment or jammers acquired on the open market.

Low power GPS jammers might not be visible to open-source tracking yet because they have not been activated as the IDF has only just begun to penetrate Gaza. Israel and the U.S. likely have intelligence (human or signals intel) as to whether they are present in numbers in Gaza or not.

But there is the possibility that they could be tactically relevant and play a role in the street battles now unfolding. As Hackaday’s author noted, the efficacy of devices costing as little as $8 is concerningly potent.

“Part of me assumed that the Mini GPS Jammer just wouldn’t work, or at least, it would work so poorly as to not be an issue. But no, in a break from tradition, a cheap imported device from eBay managed to actually exceed all of my expectations.”

If more powerful, sophisticated commercial or state-supplied portable GPS blockers can do better, another one of the technological advantages that Israel may have expected could be eroded.