> There are plenty of techniques the military could use to make jamming or spoofing almost impossible. The US DOD is not as confident as you are, as they looki

> There are plenty of techniques the military could use to make jamming or spoofing almost impossible. The US DOD is not as confident as you are, as they looking at backups/alternatives: > DOD primarily relies on GPS for accurate PNT data, which is essential to effective military operations. However, multiple threats can render GPS data unavailable or inaccurate. DOD recognizes the threats to GPS and is taking steps to address them by developing more robust GPS capabilities and alternative PNT technologies. GAO was asked to review DOD's acquisition of alternative PNT technologies. * https://www.gao.gov/products/gao-22-106010 https://www.gao.gov/products/gao-22-106010 > To fully block a military unit receiving GPS, the enemy would need to have ~30 planes in the sky over the unit, between the unit and each GPS satellite, broadcasting the jamming signal. Pretty infeasible for them. All GNSS signals live on a finite number of frequency bands: L5/E5, L2, E6, L1/E1: * https://gssc.esa.int/navipedia/index.php?title=GNSS_signal https://gssc.esa.int/navipedia/index.php?title=GNSS_signal * https://www.geospatialworld.net/blogs/gnss-frequency-bands-for-constellations/ https://www.geospatialworld.net/blogs/gnss-frequency-bands-f... * https://www.tallysman.com/gnss-constellations-radio-frequencies-and-signals/ https://www.tallysman.com/gnss-constellations-radio-frequenc... * https://en.wikipedia.org/wiki/Satellite_navigation#Frequency_allocation https://en.wikipedia.org/wiki/Satellite_navigation#Frequency... > The ITU have allocated the following L-band frequencies to GNSS (bold are aeronautically used): > *GPS, the centre frequencies are 1575.42 MHz (L1), 1227.6 MHz (L2) and 1176.45 MHz (L5). > *GLONASS operates as frequency divisional multiple access (FDMA) and there are two operational centre frequencies 1602 MHz (L1) and 1246 MHz (L2) and at 1207.14 MHz (L3). GLONASS over this decade will also introduce Code Divisional Multiple Access (CDMA) similar to GPS. > *GALILEO has a range of frequencies assigned in the L-band as follows: > ** E2 – L1 – E1 – Centre frequency 1575.42 MHz (band from 1559MHz – 1591MHz). > ** E5A – Centre frequency 1176.45 MHz (band from 1164 MHz – 1188 MHz). > ** E5B - Centre frequency 1207.14 MHz (band from 1188 MHz – 1215 MHz). > ** E6 – Centre frequency 1278,75 MHz (band from 1260 MHz – 1300 MHz). * https://pbnportal.eu/epbn/main/Overview-of-PBN/PBN-Concept---Unpacked/PBN-Infrastructure/Space-based/GNSS-Spectrum-Allocation.html https://pbnportal.eu/epbn/main/Overview-of-PBN/PBN-Concept--... A handful of planes (or drones) focussing on those few frequency ranges can do a lot of mischief. And this is not theoretical, but observed events: > Russia has been thwarting US-made mobile rocket systems in Ukraine more frequently in recent months, using electronic jammers to throw off its GPS guided targeting system to cause rockets to miss their targets, multiple people briefed on the matter told CNN. * https://www.cnn.com/2023/05/05/politics/russia-jamming-himars-rockets-ukraine/index.html https://www.cnn.com/2023/05/05/politics/russia-jamming-himar...