Image: Prof Todd Humphreys, Univ Texas Radionavigation Lab
What’s New: A graphic from Prof. Todd Humphreys showing loss of GPS/GNSS signals by satellites in Low Earth Orbit (LEO) because of jamming on the ground.
Why It’s Important:
- :Most LEO satellites use location and timing data from GPS or another GNSS to synchronize operations, and so they know where they are, when and how to broadcast.
- While most of the satellites are able to carry-over valid time and location as they pass through the area of interference, the more interference they see, the more their operations can be degraded.
What Else to Know:
- GPS/GNSS signals, and therefore jamming and spoofing signals, are line-of-sight. This is why aircraft across a large are can be impacted by jamming and spoofing, but receivers on the ground much less so. Satellites can be impacted over an even greater area.
- Some LEO satellites get their time from suites of clocks on the ground and are a bit more resilient to interference.
This slide was part of a presentation to CGSIC 2024 in Baltimore by Professor Todd Humphreys. Our thanks to Todd for his on-going insights!
Civil PNT Threats and Countermeasures
Todd Humphreys
The University of Texas at Austin
