How can they track gps devices? I thought gps devices are passive in the sense that they don’t emit any signals but only read signatures from satellites.
Or am I reading the article wrong?
> (U//PROPIN) Additionally, HawkEye 360 satellites can detect RF signals in the GPS bands, as well as other GNSS systems, e.g. GLONASS. If detected by all three spacecraft, the RF energy from a GNSS interference can be geolocated to its point of origin using an adaptation of the company’s existing geolocation techniques. Due to the global coverage of the constellation, geolocation of GNSS jamming or spoofing can be conducted over denied areas without exposing airborne or terrestrial sensors or personnel to hostile conditions.
So you can target these jamming devices with force projection and disable them to improve location services for local assets (force projection can typically switch to ring laser INS or terrain guidance when GNSS is degraded or unavailable during terminal phase).
> HawkEye 360 satellites can detect RF signals in the GPS bands, as well as other GNSS systems, e.g. GLONASS
Seems like a misunderstanding. They claim detection in that frequency, not GPS devices that listen to that frequency. So jammers, probably.
There are also panic buttons for remote backpackers that collect gps coordinates and send them to a satellite. All things I wouldn't call satellite phones, even if they're basically just more rudimentary versions. Looks like the quote was referring to something else, though.
GNSS receivers are passive devices just like regular radio receivers, but in addition to regular radios they use math to process the deltas from GNSS satellite clock signals to pinpoint their position.
Exceptions to (most) include plasma antennas, which can disappear on demand.
In theory, a reflector antenna can have a zero RCS, so putting a reflector behind a dipole will reduce the RCS. It’s totally non-intuitive.